Fix up typos.
Move "query result" tables to left side of page (remove leading spaces).
This commit is contained in:
Thomas G. Lockhart
parent
ff7b9f5541
commit
ee7f92b76b
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@ -1,5 +1,5 @@
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<!--
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$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.9 2000/05/02 20:01:52 thomas Exp $
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$Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.10 2000/06/14 13:10:48 thomas Exp $
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-->
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<chapter id="sql">
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@ -155,20 +155,22 @@ $Header: /cvsroot/pgsql/doc/src/sgml/sql.sgml,v 1.9 2000/05/02 20:01:52 thomas E
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<example>
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<title id="supplier-fig">The Suppliers and Parts Database</title>
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<programlisting>
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SUPPLIER SNO | SNAME | CITY SELLS SNO | PNO
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-----+---------+-------- -----+-----
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1 | Smith | London 1 | 1
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2 | Jones | Paris 1 | 2
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3 | Adams | Vienna 2 | 4
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4 | Blake | Rome 3 | 1
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3 | 3
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4 | 2
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PART PNO | PNAME | PRICE 4 | 3
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-----+---------+--------- 4 | 4
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1 | Screw | 10
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2 | Nut | 8
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3 | Bolt | 15
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4 | Cam | 25
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SUPPLIER: SELLS:
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SNO | SNAME | CITY SNO | PNO
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----+---------+-------- -----+-----
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1 | Smith | London 1 | 1
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2 | Jones | Paris 1 | 2
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3 | Adams | Vienna 2 | 4
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4 | Blake | Rome 3 | 1
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3 | 3
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4 | 2
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PART: 4 | 3
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PNO | PNAME | PRICE 4 | 4
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----+---------+---------
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1 | Screw | 10
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2 | Nut | 8
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3 | Bolt | 15
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4 | Cam | 25
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</programlisting>
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</example>
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</para>
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@ -474,7 +476,7 @@ attributes are taken from. We often write a relation scheme as
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INTERSECT (∩): builds the set-theoretic intersection of two
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tables. Given the tables <classname>R</classname> and
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<classname>S</classname>,
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<classname>R</classname> ∪ <classname>S</classname> is the
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<classname>R</classname> ∩ <classname>S</classname> is the
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set of tuples
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that are in <classname>R</classname> and in
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<classname>S</classname>.
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@ -532,11 +534,12 @@ attributes are taken from. We often write a relation scheme as
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Let the following two tables be given:
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<programlisting>
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R A | B | C S C | D | E
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---+---+--- ---+---+---
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1 | 2 | 3 3 | a | b
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4 | 5 | 6 6 | c | d
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7 | 8 | 9
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R: S:
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A | B | C C | D | E
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---+---+--- ---+---+---
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1 | 2 | 3 3 | a | b
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4 | 5 | 6 6 | c | d
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7 | 8 | 9
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</programlisting>
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</para>
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</example>
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@ -547,14 +550,15 @@ attributes are taken from. We often write a relation scheme as
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get:
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<programlisting>
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R x S A | B | R.C | S.C | D | E
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---+---+-----+-----+---+---
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1 | 2 | 3 | 3 | a | b
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1 | 2 | 3 | 6 | c | d
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4 | 5 | 6 | 3 | a | b
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4 | 5 | 6 | 6 | c | d
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7 | 8 | 9 | 3 | a | b
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7 | 8 | 9 | 6 | c | d
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R x S:
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A | B | R.C | S.C | D | E
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---+---+-----+-----+---+---
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1 | 2 | 3 | 3 | a | b
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1 | 2 | 3 | 6 | c | d
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4 | 5 | 6 | 3 | a | b
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4 | 5 | 6 | 6 | c | d
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7 | 8 | 9 | 3 | a | b
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7 | 8 | 9 | 6 | c | d
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</programlisting>
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</para>
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@ -564,10 +568,10 @@ attributes are taken from. We often write a relation scheme as
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we get:
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<programlisting>
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A | B | R.C | S.C | D | E
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---+---+-----+-----+---+---
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1 | 2 | 3 | 3 | a | b
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4 | 5 | 6 | 6 | c | d
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A | B | R.C | S.C | D | E
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---+---+-----+-----+---+---
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1 | 2 | 3 | 3 | a | b
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4 | 5 | 6 | 6 | c | d
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</programlisting>
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</para>
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@ -579,10 +583,10 @@ attributes are taken from. We often write a relation scheme as
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and get:
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<programlisting>
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A | B | C | D | E
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---+---+---+---+---
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1 | 2 | 3 | a | b
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4 | 5 | 6 | c | d
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A | B | C | D | E
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---+---+---+---+---
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1 | 2 | 3 | a | b
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4 | 5 | 6 | c | d
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</programlisting>
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</para>
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</listitem>
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@ -595,8 +599,9 @@ attributes are taken from. We often write a relation scheme as
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C and D.
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Then we define the division as:
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R ÷ S = {t ∣ ∀ t<subscript>s</subscript> ∈ S
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∃ t<subscript>r</subscript> ∈ R
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<programlisting>
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R ÷ S = {t ∣ ∀ t<subscript>s</subscript> ∈ S ∃ t<subscript>r</subscript> ∈ R
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</programlisting>
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such that
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t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>s</subscript>}
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@ -614,24 +619,25 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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Given the following tables
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<programlisting>
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R A | B | C | D S C | D
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---+---+---+--- ---+---
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a | b | c | d c | d
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a | b | e | f e | f
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b | c | e | f
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e | d | c | d
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e | d | e | f
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a | b | d | e
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R: S:
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A | B | C | D C | D
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---+---+---+--- ---+---
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a | b | c | d c | d
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a | b | e | f e | f
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b | c | e | f
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e | d | c | d
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e | d | e | f
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a | b | d | e
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</programlisting>
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R ÷ S
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is derived as
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<programlisting>
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A | B
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---+---
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a | b
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e | d
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A | B
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---+---
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a | b
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e | d
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</programlisting>
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</para>
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</listitem>
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@ -668,10 +674,10 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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we will obtain the following result:
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<programlisting>
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SNAME
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-------
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Smith
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Adams
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SNAME
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-------
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Smith
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Adams
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</programlisting>
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</para>
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</example>
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@ -720,7 +726,10 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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<para>
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The queries used in <acronym>TRC</acronym> are of the following
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form:
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x(A) ∣ F(x)
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<programlisting>
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x(A) ∣ F(x)
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</programlisting>
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where <literal>x</literal> is a tuple variable
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<classname>A</classname> is a set of attributes and <literal>F</literal> is a
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@ -733,11 +742,11 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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<xref linkend="suppl-rel-alg" endterm="suppl-rel-alg">
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using <acronym>TRC</acronym> we formulate the following query:
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<programlisting>
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{x(SNAME) ∣ x ∈ SUPPLIER ∧ \nonumber
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∃ y ∈ SELLS ∃ z ∈ PART (y(SNO)=x(SNO) ∧ \nonumber
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z(PNO)=y(PNO) ∧ \nonumber
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z(PNAME)='Screw')} \nonumber
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<programlisting>
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{x(SNAME) ∣ x ∈ SUPPLIER ∧
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∃ y ∈ SELLS ∃ z ∈ PART (y(SNO)=x(SNO) ∧
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z(PNO)=y(PNO) ∧
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z(PNAME)='Screw')}
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</programlisting>
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</para>
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@ -806,7 +815,9 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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to involve
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arithmetic operations as well as comparisons, e.g.
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A < B + 3.
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<programlisting>
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A < B + 3.
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</programlisting>
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Note
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that + or other arithmetic operators appear neither in relational
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@ -843,17 +854,17 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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used to retrieve data. The syntax is:
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<synopsis>
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SELECT [ALL|DISTINCT]
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{ * | <replaceable class="parameter">expr_1</replaceable> [AS <replaceable class="parameter">c_alias_1</replaceable>] [, ...
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[, <replaceable class="parameter">expr_k</replaceable> [AS <replaceable class="parameter">c_alias_k</replaceable>]]]}
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FROM <replaceable class="parameter">table_name_1</replaceable> [<replaceable class="parameter">t_alias_1</replaceable>]
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[, ... [, <replaceable class="parameter">table_name_n</replaceable> [<replaceable class="parameter">t_alias_n</replaceable>]]]
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[WHERE <replaceable class="parameter">condition</replaceable>]
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[GROUP BY <replaceable class="parameter">name_of_attr_i</replaceable>
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[,... [, <replaceable class="parameter">name_of_attr_j</replaceable>]] [HAVING <replaceable class="parameter">condition</replaceable>]]
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[{UNION [ALL] | INTERSECT | EXCEPT} SELECT ...]
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[ORDER BY <replaceable class="parameter">name_of_attr_i</replaceable> [ASC|DESC]
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[, ... [, <replaceable class="parameter">name_of_attr_j</replaceable> [ASC|DESC]]]];
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SELECT [ALL|DISTINCT]
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{ * | <replaceable class="parameter">expr_1</replaceable> [AS <replaceable class="parameter">c_alias_1</replaceable>] [, ...
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[, <replaceable class="parameter">expr_k</replaceable> [AS <replaceable class="parameter">c_alias_k</replaceable>]]]}
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FROM <replaceable class="parameter">table_name_1</replaceable> [<replaceable class="parameter">t_alias_1</replaceable>]
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[, ... [, <replaceable class="parameter">table_name_n</replaceable> [<replaceable class="parameter">t_alias_n</replaceable>]]]
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[WHERE <replaceable class="parameter">condition</replaceable>]
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[GROUP BY <replaceable class="parameter">name_of_attr_i</replaceable>
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[,... [, <replaceable class="parameter">name_of_attr_j</replaceable>]] [HAVING <replaceable class="parameter">condition</replaceable>]]
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[{UNION [ALL] | INTERSECT | EXCEPT} SELECT ...]
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[ORDER BY <replaceable class="parameter">name_of_attr_i</replaceable> [ASC|DESC]
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[, ... [, <replaceable class="parameter">name_of_attr_j</replaceable> [ASC|DESC]]]];
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</synopsis>
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</para>
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@ -876,17 +887,17 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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greater than 10 we formulate the following query:
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<programlisting>
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SELECT * FROM PART
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WHERE PRICE > 10;
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SELECT * FROM PART
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WHERE PRICE > 10;
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</programlisting>
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and get the table:
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<programlisting>
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PNO | PNAME | PRICE
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-----+---------+--------
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3 | Bolt | 15
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4 | Cam | 25
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PNO | PNAME | PRICE
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-----+---------+--------
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3 | Bolt | 15
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4 | Cam | 25
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</programlisting>
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</para>
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@ -896,9 +907,9 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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from table PART we use the statement:
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<programlisting>
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SELECT PNAME, PRICE
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FROM PART
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WHERE PRICE > 10;
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SELECT PNAME, PRICE
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FROM PART
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WHERE PRICE > 10;
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</programlisting>
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In this case the result is:
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@ -920,18 +931,18 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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using the keywords OR, AND, and NOT:
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<programlisting>
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SELECT PNAME, PRICE
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FROM PART
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WHERE PNAME = 'Bolt' AND
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SELECT PNAME, PRICE
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FROM PART
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WHERE PNAME = 'Bolt' AND
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(PRICE = 0 OR PRICE < 15);
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</programlisting>
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will lead to the result:
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<programlisting>
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PNAME | PRICE
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--------+--------
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Bolt | 15
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PNAME | PRICE
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--------+--------
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Bolt | 15
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</programlisting>
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</para>
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@ -941,19 +952,19 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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take two pieces of a part we could use the following query:
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<programlisting>
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SELECT PNAME, PRICE * 2 AS DOUBLE
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FROM PART
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WHERE PRICE * 2 < 50;
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SELECT PNAME, PRICE * 2 AS DOUBLE
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FROM PART
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WHERE PRICE * 2 < 50;
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</programlisting>
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and we get:
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<programlisting>
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PNAME | DOUBLE
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--------+---------
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Screw | 20
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Nut | 16
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Bolt | 30
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PNAME | DOUBLE
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--------+---------
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Screw | 20
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Nut | 16
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Bolt | 30
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</programlisting>
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Note that the word DOUBLE after the keyword AS is the new title of the
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@ -980,25 +991,25 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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attributes we formulate the following statement:
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<programlisting>
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SELECT S.SNAME, P.PNAME
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FROM SUPPLIER S, PART P, SELLS SE
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WHERE S.SNO = SE.SNO AND
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P.PNO = SE.PNO;
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SELECT S.SNAME, P.PNAME
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FROM SUPPLIER S, PART P, SELLS SE
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WHERE S.SNO = SE.SNO AND
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P.PNO = SE.PNO;
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</programlisting>
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and get the following table as a result:
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<programlisting>
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SNAME | PNAME
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-------+-------
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Smith | Screw
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Smith | Nut
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Jones | Cam
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Adams | Screw
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Adams | Bolt
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Blake | Nut
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Blake | Bolt
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Blake | Cam
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SNAME | PNAME
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-------+-------
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Smith | Screw
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Smith | Nut
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Jones | Cam
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Adams | Screw
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Adams | Bolt
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Blake | Nut
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Blake | Bolt
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Blake | Cam
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</programlisting>
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</para>
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@ -1040,8 +1051,8 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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the following query:
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<programlisting>
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SELECT AVG(PRICE) AS AVG_PRICE
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FROM PART;
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SELECT AVG(PRICE) AS AVG_PRICE
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FROM PART;
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</programlisting>
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</para>
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@ -1049,9 +1060,9 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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The result is:
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<programlisting>
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AVG_PRICE
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-----------
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14.5
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AVG_PRICE
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-----------
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14.5
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</programlisting>
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</para>
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@ -1060,16 +1071,16 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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the statement:
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<programlisting>
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SELECT COUNT(PNO)
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FROM PART;
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SELECT COUNT(PNO)
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FROM PART;
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</programlisting>
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and get:
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<programlisting>
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COUNT
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-------
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4
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COUNT
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-------
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4
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</programlisting>
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</para>
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@ -1108,21 +1119,21 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
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formulate the query:
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<programlisting>
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SELECT S.SNO, S.SNAME, COUNT(SE.PNO)
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FROM SUPPLIER S, SELLS SE
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WHERE S.SNO = SE.SNO
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GROUP BY S.SNO, S.SNAME;
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SELECT S.SNO, S.SNAME, COUNT(SE.PNO)
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FROM SUPPLIER S, SELLS SE
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WHERE S.SNO = SE.SNO
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GROUP BY S.SNO, S.SNAME;
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</programlisting>
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and get:
|
||||
|
||||
<programlisting>
|
||||
SNO | SNAME | COUNT
|
||||
-----+-------+-------
|
||||
1 | Smith | 2
|
||||
2 | Jones | 1
|
||||
3 | Adams | 2
|
||||
4 | Blake | 3
|
||||
SNO | SNAME | COUNT
|
||||
-----+-------+-------
|
||||
1 | Smith | 2
|
||||
2 | Jones | 1
|
||||
3 | Adams | 2
|
||||
4 | Blake | 3
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1132,16 +1143,16 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
|
|||
tables SUPPLIER and SELLS is derived:
|
||||
|
||||
<programlisting>
|
||||
S.SNO | S.SNAME | SE.PNO
|
||||
-------+---------+--------
|
||||
1 | Smith | 1
|
||||
1 | Smith | 2
|
||||
2 | Jones | 4
|
||||
3 | Adams | 1
|
||||
3 | Adams | 3
|
||||
4 | Blake | 2
|
||||
4 | Blake | 3
|
||||
4 | Blake | 4
|
||||
S.SNO | S.SNAME | SE.PNO
|
||||
-------+---------+--------
|
||||
1 | Smith | 1
|
||||
1 | Smith | 2
|
||||
2 | Jones | 4
|
||||
3 | Adams | 1
|
||||
3 | Adams | 3
|
||||
4 | Blake | 2
|
||||
4 | Blake | 3
|
||||
4 | Blake | 4
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1150,19 +1161,19 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
|
|||
together that agree on both attributes S.SNO and S.SNAME:
|
||||
|
||||
<programlisting>
|
||||
S.SNO | S.SNAME | SE.PNO
|
||||
-------+---------+--------
|
||||
1 | Smith | 1
|
||||
| 2
|
||||
--------------------------
|
||||
2 | Jones | 4
|
||||
--------------------------
|
||||
3 | Adams | 1
|
||||
| 3
|
||||
--------------------------
|
||||
4 | Blake | 2
|
||||
| 3
|
||||
| 4
|
||||
S.SNO | S.SNAME | SE.PNO
|
||||
-------+---------+--------
|
||||
1 | Smith | 1
|
||||
| 2
|
||||
--------------------------
|
||||
2 | Jones | 4
|
||||
--------------------------
|
||||
3 | Adams | 1
|
||||
| 3
|
||||
--------------------------
|
||||
4 | Blake | 2
|
||||
| 3
|
||||
| 4
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1204,21 +1215,21 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
|
|||
query:
|
||||
|
||||
<programlisting>
|
||||
SELECT S.SNO, S.SNAME, COUNT(SE.PNO)
|
||||
FROM SUPPLIER S, SELLS SE
|
||||
WHERE S.SNO = SE.SNO
|
||||
GROUP BY S.SNO, S.SNAME
|
||||
HAVING COUNT(SE.PNO) > 1;
|
||||
SELECT S.SNO, S.SNAME, COUNT(SE.PNO)
|
||||
FROM SUPPLIER S, SELLS SE
|
||||
WHERE S.SNO = SE.SNO
|
||||
GROUP BY S.SNO, S.SNAME
|
||||
HAVING COUNT(SE.PNO) > 1;
|
||||
</programlisting>
|
||||
|
||||
and get:
|
||||
|
||||
<programlisting>
|
||||
SNO | SNAME | COUNT
|
||||
-----+-------+-------
|
||||
1 | Smith | 2
|
||||
3 | Adams | 2
|
||||
4 | Blake | 3
|
||||
SNO | SNAME | COUNT
|
||||
-----+-------+-------
|
||||
1 | Smith | 2
|
||||
3 | Adams | 2
|
||||
4 | Blake | 3
|
||||
</programlisting>
|
||||
</para>
|
||||
</example>
|
||||
|
|
@ -1243,10 +1254,10 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
|
|||
named 'Screw' we use the query:
|
||||
|
||||
<programlisting>
|
||||
SELECT *
|
||||
FROM PART
|
||||
WHERE PRICE > (SELECT PRICE FROM PART
|
||||
WHERE PNAME='Screw');
|
||||
SELECT *
|
||||
FROM PART
|
||||
WHERE PRICE > (SELECT PRICE FROM PART
|
||||
WHERE PNAME='Screw');
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1254,10 +1265,10 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
|
|||
The result is:
|
||||
|
||||
<programlisting>
|
||||
PNO | PNAME | PRICE
|
||||
-----+---------+--------
|
||||
3 | Bolt | 15
|
||||
4 | Cam | 25
|
||||
PNO | PNAME | PRICE
|
||||
-----+---------+--------
|
||||
3 | Bolt | 15
|
||||
4 | Cam | 25
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1272,16 +1283,16 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
|
|||
greater.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
<para>
|
||||
If we want to know all suppliers that do not sell any part
|
||||
(e.g. to be able to remove these suppliers from the database) we use:
|
||||
|
||||
<programlisting>
|
||||
SELECT *
|
||||
FROM SUPPLIER S
|
||||
WHERE NOT EXISTS
|
||||
(SELECT * FROM SELLS SE
|
||||
WHERE SE.SNO = S.SNO);
|
||||
SELECT *
|
||||
FROM SUPPLIER S
|
||||
WHERE NOT EXISTS
|
||||
(SELECT * FROM SELLS SE
|
||||
WHERE SE.SNO = S.SNO);
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1310,22 +1321,22 @@ t<subscript>r</subscript>(A,B)=t∧t<subscript>r</subscript>(C,D)=t<subscript>
|
|||
The following query is an example for UNION:
|
||||
|
||||
<programlisting>
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNAME = 'Jones'
|
||||
UNION
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNAME = 'Adams';
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNAME = 'Jones'
|
||||
UNION
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNAME = 'Adams';
|
||||
</programlisting>
|
||||
|
||||
gives the result:
|
||||
|
||||
<programlisting>
|
||||
SNO | SNAME | CITY
|
||||
-----+-------+--------
|
||||
2 | Jones | Paris
|
||||
3 | Adams | Vienna
|
||||
SNO | SNAME | CITY
|
||||
-----+-------+--------
|
||||
2 | Jones | Paris
|
||||
3 | Adams | Vienna
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1333,45 +1344,46 @@ gives the result:
|
|||
Here an example for INTERSECT:
|
||||
|
||||
<programlisting>
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 1
|
||||
INTERSECT
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 2;
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 1
|
||||
INTERSECT
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 2;
|
||||
</programlisting>
|
||||
|
||||
gives the result:
|
||||
|
||||
<programlisting>
|
||||
SNO | SNAME | CITY
|
||||
-----+-------+--------
|
||||
2 | Jones | Paris
|
||||
The only tuple returned by both parts of the query is the one having $SNO=2$.
|
||||
SNO | SNAME | CITY
|
||||
-----+-------+--------
|
||||
2 | Jones | Paris
|
||||
</programlisting>
|
||||
|
||||
The only tuple returned by both parts of the query is the one having $SNO=2$.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Finally an example for EXCEPT:
|
||||
|
||||
<programlisting>
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 1
|
||||
EXCEPT
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 3;
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 1
|
||||
EXCEPT
|
||||
SELECT S.SNO, S.SNAME, S.CITY
|
||||
FROM SUPPLIER S
|
||||
WHERE S.SNO > 3;
|
||||
</programlisting>
|
||||
|
||||
gives the result:
|
||||
|
||||
<programlisting>
|
||||
SNO | SNAME | CITY
|
||||
-----+-------+--------
|
||||
2 | Jones | Paris
|
||||
3 | Adams | Vienna
|
||||
SNO | SNAME | CITY
|
||||
-----+-------+--------
|
||||
2 | Jones | Paris
|
||||
3 | Adams | Vienna
|
||||
</programlisting>
|
||||
</para>
|
||||
</example>
|
||||
|
|
@ -1395,11 +1407,11 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
one that creates a new relation (a new table). The syntax of the
|
||||
CREATE TABLE command is:
|
||||
|
||||
<synopsis>
|
||||
CREATE TABLE <replaceable class="parameter">table_name</replaceable>
|
||||
(<replaceable class="parameter">name_of_attr_1</replaceable> <replaceable class="parameter">type_of_attr_1</replaceable>
|
||||
[, <replaceable class="parameter">name_of_attr_2</replaceable> <replaceable class="parameter">type_of_attr_2</replaceable>
|
||||
[, ...]]);
|
||||
<synopsis>
|
||||
CREATE TABLE <replaceable class="parameter">table_name</replaceable>
|
||||
(<replaceable class="parameter">name_of_attr_1</replaceable> <replaceable class="parameter">type_of_attr_1</replaceable>
|
||||
[, <replaceable class="parameter">name_of_attr_2</replaceable> <replaceable class="parameter">type_of_attr_2</replaceable>
|
||||
[, ...]]);
|
||||
</synopsis>
|
||||
|
||||
<example>
|
||||
|
|
@ -1411,23 +1423,23 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
following <acronym>SQL</acronym> statements are used:
|
||||
|
||||
<programlisting>
|
||||
CREATE TABLE SUPPLIER
|
||||
(SNO INTEGER,
|
||||
SNAME VARCHAR(20),
|
||||
CITY VARCHAR(20));
|
||||
</programlisting>
|
||||
CREATE TABLE SUPPLIER
|
||||
(SNO INTEGER,
|
||||
SNAME VARCHAR(20),
|
||||
CITY VARCHAR(20));
|
||||
</programlisting>
|
||||
|
||||
<programlisting>
|
||||
CREATE TABLE PART
|
||||
(PNO INTEGER,
|
||||
PNAME VARCHAR(20),
|
||||
PRICE DECIMAL(4 , 2));
|
||||
</programlisting>
|
||||
<programlisting>
|
||||
CREATE TABLE PART
|
||||
(PNO INTEGER,
|
||||
PNAME VARCHAR(20),
|
||||
PRICE DECIMAL(4 , 2));
|
||||
</programlisting>
|
||||
|
||||
<programlisting>
|
||||
CREATE TABLE SELLS
|
||||
(SNO INTEGER,
|
||||
PNO INTEGER);
|
||||
<programlisting>
|
||||
CREATE TABLE SELLS
|
||||
(SNO INTEGER,
|
||||
PNO INTEGER);
|
||||
</programlisting>
|
||||
</para>
|
||||
</example>
|
||||
|
|
@ -1463,7 +1475,7 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
<replaceable class="parameter">q</replaceable>
|
||||
of them right to the decimal point.
|
||||
|
||||
(15 ≥ <replaceable class="parameter">p</replaceable> ≥ <replaceable class="parameter">q</replaceable>q ≥ 0).
|
||||
(15 ≥ <replaceable class="parameter">p</replaceable> ≥ <replaceable class="parameter">q</replaceable> ≥ 0).
|
||||
|
||||
If <replaceable class="parameter">q</replaceable>
|
||||
is omitted it is assumed to be 0.
|
||||
|
|
@ -1514,8 +1526,8 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
the CREATE INDEX command is used. The syntax is:
|
||||
|
||||
<programlisting>
|
||||
CREATE INDEX <replaceable class="parameter">index_name</replaceable>
|
||||
ON <replaceable class="parameter">table_name</replaceable> ( <replaceable class="parameter">name_of_attribute</replaceable> );
|
||||
CREATE INDEX <replaceable class="parameter">index_name</replaceable>
|
||||
ON <replaceable class="parameter">table_name</replaceable> ( <replaceable class="parameter">name_of_attribute</replaceable> );
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1528,8 +1540,7 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
we use the following statement:
|
||||
|
||||
<programlisting>
|
||||
CREATE INDEX I
|
||||
ON SUPPLIER (SNAME);
|
||||
CREATE INDEX I ON SUPPLIER (SNAME);
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1578,8 +1589,8 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
is:
|
||||
|
||||
<programlisting>
|
||||
CREATE VIEW <replaceable class="parameter">view_name</replaceable>
|
||||
AS <replaceable class="parameter">select_stmt</replaceable>
|
||||
CREATE VIEW <replaceable class="parameter">view_name</replaceable>
|
||||
AS <replaceable class="parameter">select_stmt</replaceable>
|
||||
</programlisting>
|
||||
|
||||
where <replaceable class="parameter">select_stmt</replaceable>
|
||||
|
|
@ -1597,12 +1608,12 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
<xref linkend="supplier-fig" endterm="supplier-fig"> again):
|
||||
|
||||
<programlisting>
|
||||
CREATE VIEW London_Suppliers
|
||||
AS SELECT S.SNAME, P.PNAME
|
||||
FROM SUPPLIER S, PART P, SELLS SE
|
||||
WHERE S.SNO = SE.SNO AND
|
||||
P.PNO = SE.PNO AND
|
||||
S.CITY = 'London';
|
||||
CREATE VIEW London_Suppliers
|
||||
AS SELECT S.SNAME, P.PNAME
|
||||
FROM SUPPLIER S, PART P, SELLS SE
|
||||
WHERE S.SNO = SE.SNO AND
|
||||
P.PNO = SE.PNO AND
|
||||
S.CITY = 'London';
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1612,17 +1623,16 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
if it were another base table:
|
||||
|
||||
<programlisting>
|
||||
SELECT *
|
||||
FROM London_Suppliers
|
||||
WHERE P.PNAME = 'Screw';
|
||||
SELECT * FROM London_Suppliers
|
||||
WHERE P.PNAME = 'Screw';
|
||||
</programlisting>
|
||||
|
||||
which will return the following table:
|
||||
|
||||
<programlisting>
|
||||
SNAME | PNAME
|
||||
-------+-------
|
||||
Smith | Screw
|
||||
SNAME | PNAME
|
||||
-------+-------
|
||||
Smith | Screw
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1646,7 +1656,7 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
DROP TABLE command is used:
|
||||
|
||||
<programlisting>
|
||||
DROP TABLE <replaceable class="parameter">table_name</replaceable>;
|
||||
DROP TABLE <replaceable class="parameter">table_name</replaceable>;
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1654,7 +1664,7 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
To destroy the SUPPLIER table use the following statement:
|
||||
|
||||
<programlisting>
|
||||
DROP TABLE SUPPLIER;
|
||||
DROP TABLE SUPPLIER;
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1662,7 +1672,7 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
The DROP INDEX command is used to destroy an index:
|
||||
|
||||
<programlisting>
|
||||
DROP INDEX <replaceable class="parameter">index_name</replaceable>;
|
||||
DROP INDEX <replaceable class="parameter">index_name</replaceable>;
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1670,7 +1680,7 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
Finally to destroy a given view use the command DROP VIEW:
|
||||
|
||||
<programlisting>
|
||||
DROP VIEW <replaceable class="parameter">view_name</replaceable>;
|
||||
DROP VIEW <replaceable class="parameter">view_name</replaceable>;
|
||||
</programlisting>
|
||||
</para>
|
||||
</sect3>
|
||||
|
|
@ -1689,10 +1699,9 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
The syntax is:
|
||||
|
||||
<programlisting>
|
||||
INSERT INTO <replaceable class="parameter">table_name</replaceable> (<replaceable class="parameter">name_of_attr_1</replaceable>
|
||||
[, <replaceable class="parameter">name_of_attr_2</replaceable> [,...]])
|
||||
VALUES (<replaceable class="parameter">val_attr_1</replaceable>
|
||||
[, <replaceable class="parameter">val_attr_2</replaceable> [, ...]]);
|
||||
INSERT INTO <replaceable class="parameter">table_name</replaceable> (<replaceable class="parameter">name_of_attr_1</replaceable>
|
||||
[, <replaceable class="parameter">name_of_attr_2</replaceable> [,...]])
|
||||
VALUES (<replaceable class="parameter">val_attr_1</replaceable> [, <replaceable class="parameter">val_attr_2</replaceable> [, ...]]);
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1702,8 +1711,8 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
following statement:
|
||||
|
||||
<programlisting>
|
||||
INSERT INTO SUPPLIER (SNO, SNAME, CITY)
|
||||
VALUES (1, 'Smith', 'London');
|
||||
INSERT INTO SUPPLIER (SNO, SNAME, CITY)
|
||||
VALUES (1, 'Smith', 'London');
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1711,8 +1720,8 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
To insert the first tuple into the relation SELLS we use:
|
||||
|
||||
<programlisting>
|
||||
INSERT INTO SELLS (SNO, PNO)
|
||||
VALUES (1, 1);
|
||||
INSERT INTO SELLS (SNO, PNO)
|
||||
VALUES (1, 1);
|
||||
</programlisting>
|
||||
</para>
|
||||
</sect3>
|
||||
|
|
@ -1725,10 +1734,10 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
UPDATE command is used. The syntax is:
|
||||
|
||||
<programlisting>
|
||||
UPDATE <replaceable class="parameter">table_name</replaceable>
|
||||
SET <replaceable class="parameter">name_of_attr_1</replaceable> = <replaceable class="parameter">value_1</replaceable>
|
||||
[, ... [, <replaceable class="parameter">name_of_attr_k</replaceable> = <replaceable class="parameter">value_k</replaceable>]]
|
||||
WHERE <replaceable class="parameter">condition</replaceable>;
|
||||
UPDATE <replaceable class="parameter">table_name</replaceable>
|
||||
SET <replaceable class="parameter">name_of_attr_1</replaceable> = <replaceable class="parameter">value_1</replaceable>
|
||||
[, ... [, <replaceable class="parameter">name_of_attr_k</replaceable> = <replaceable class="parameter">value_k</replaceable>]]
|
||||
WHERE <replaceable class="parameter">condition</replaceable>;
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1737,9 +1746,9 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
relation PART we use:
|
||||
|
||||
<programlisting>
|
||||
UPDATE PART
|
||||
SET PRICE = 15
|
||||
WHERE PNAME = 'Screw';
|
||||
UPDATE PART
|
||||
SET PRICE = 15
|
||||
WHERE PNAME = 'Screw';
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1757,8 +1766,8 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
FROM. The syntax is:
|
||||
|
||||
<programlisting>
|
||||
DELETE FROM <replaceable class="parameter">table_name</replaceable>
|
||||
WHERE <replaceable class="parameter">condition</replaceable>;
|
||||
DELETE FROM <replaceable class="parameter">table_name</replaceable>
|
||||
WHERE <replaceable class="parameter">condition</replaceable>;
|
||||
</programlisting>
|
||||
</para>
|
||||
|
||||
|
|
@ -1767,8 +1776,8 @@ The only tuple returned by both parts of the query is the one having $SNO=2$.
|
|||
following statement is used:
|
||||
|
||||
<programlisting>
|
||||
DELETE FROM SUPPLIER
|
||||
WHERE SNAME = 'Smith';
|
||||
DELETE FROM SUPPLIER
|
||||
WHERE SNAME = 'Smith';
|
||||
</programlisting>
|
||||
</para>
|
||||
</sect3>
|
||||
|
|
|
|||
Loading…
Reference in New Issue