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libpgtcl.sgml still needs work, but at least there are 

fewer errors than there were.
This commit is contained in:
Tom Lane 1998-10-08 03:23:03 +00:00
parent deaaf96975
commit 0a1c2805b3
1 changed files with 402 additions and 227 deletions
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629
doc/src/sgml/libpgtcl.sgml
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@ -14,12 +14,6 @@ This package was originally written by Jolly Chen.
<Sect1>
<Title>Commands</Title>
<Para>
The pg_lo* routines are interfaces to the Inversion Large Objects in <ProductName>Postgres</ProductName>.
The functions are designed to mimic the analogous file system functions in
the standard Unix file system interface.
</Para>
<Para>
<TABLE TOCENTRY="1">
<TITLE>PGTCL Commands</TITLE>
@ -110,7 +104,11 @@ These commands are described further on subsequent pages.
</Para>
<Para>
The pg_lo* routines should typically be used within a BEGIN/END transaction
The pg_lo* routines are interfaces to the Large Object features of
<ProductName>Postgres</ProductName>.
The functions are designed to mimic the analogous file system functions in
the standard Unix file system interface.
The pg_lo* routines should be used within a BEGIN/END transaction
block because the file descriptor returned by pg_lo_open is only valid for
the current transaction. pg_lo_import and pg_lo_export MUST be used
in a BEGIN/END transaction block.
@ -137,6 +135,7 @@ proc getDBs { {host "localhost"} {port "5432"} } {
for {set i 0} {$i < $ntups} {incr i} {
lappend datnames [pg_result $res -getTuple $i]
}
pg_result $res -clear
pg_disconnect $conn
return $datnames
}
@ -167,14 +166,20 @@ proc getDBs { {host "localhost"} {port "5432"} } {
</REFSYNOPSISDIVINFO>
<SYNOPSIS>
pg_connect <REPLACEABLE CLASS="PARAMETER">dbName</REPLACEABLE> <OPTIONAL>-host <REPLACEABLE CLASS="PARAMETER">hostName</REPLACEABLE></OPTIONAL>
<OPTIONAL>-port <REPLACEABLE CLASS="PARAMETER">portNumber</REPLACEABLE></OPTIONAL> <OPTIONAL>-tty <REPLACEABLE CLASS="PARAMETER">pqtty</REPLACEABLE></OPTIONAL> <OPTIONAL>-options <REPLACEABLE CLASS="PARAMETER">optionalBackendArgs</REPLACEABLE></OPTIONAL>
<OPTIONAL>-port <REPLACEABLE
CLASS="PARAMETER">portNumber</REPLACEABLE></OPTIONAL> <OPTIONAL>-tty
<REPLACEABLE CLASS="PARAMETER">pqtty</REPLACEABLE></OPTIONAL>
<OPTIONAL>-options <REPLACEABLE
CLASS="PARAMETER">optionalBackendArgs</REPLACEABLE></OPTIONAL>
<para>
pg_connect -conninfo <REPLACEABLE CLASS="PARAMETER">connectOptions</REPLACEABLE>
</SYNOPSIS>
<REFSECT2 ID="R2-PGTCL-PGCONNECT-1">
<REFSECT2INFO>
<DATE>1997-12-24</DATE>
</REFSECT2INFO>
<TITLE>Inputs
<TITLE>Inputs (old style)
</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
@ -227,6 +232,25 @@ pg_connect <REPLACEABLE CLASS="PARAMETER">dbName</REPLACEABLE> <OPTIONAL>-host <
<REFSECT2 ID="R2-PGTCL-PGCONNECT-2">
<REFSECT2INFO>
<DATE>1998-10-07</DATE>
</REFSECT2INFO>
<TITLE>Inputs (new style)
</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">connectOptions</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>A string of connection options, each written in the form keyword = value.
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
</REFSECT2>
<REFSECT2 ID="R2-PGTCL-PGCONNECT-3">
<REFSECT2INFO>
<DATE>1997-12-24</DATE>
</REFSECT2INFO>
<TITLE>Outputs
@ -238,8 +262,8 @@ pg_connect <REPLACEABLE CLASS="PARAMETER">dbName</REPLACEABLE> <OPTIONAL>-host <
</TERM>
<LISTITEM>
<PARA>
The return result is either an error message or a handle for a database
connection. Handles start with the prefix "pgsql"
If successful, a handle for a database connection is returned.
Handles start with the prefix "pgsql".
</PARA>
</LISTITEM>
</VARLISTENTRY>
@ -255,7 +279,15 @@ The return result is either an error message or a handle for a database
</REFSECT1INFO>
<TITLE>Description
</TITLE>
<PARA><FUNCTION>pg_connect</FUNCTION> opens a connection to the <ProductName>Postgres</ProductName> backend.
<PARA><FUNCTION>pg_connect</FUNCTION> opens a connection to the
<ProductName>Postgres</ProductName> backend.
<para>
Two syntaxes are available. In the older one, each possible option
has a separate option switch in the pg_connect statement. In the
newer form, a single option string is supplied that can contain
multiple option values. See <FUNCTION>pg_conndefaults</FUNCTION>
for info about the available options in the newer syntax.
</PARA>
</REFSECT1>
<REFSECT1 ID="R1-PGTCL-PGCONNECT-2">
@ -338,10 +370,91 @@ pg_disconnect <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE>
</REFENTRY>
<REFENTRY ID="PGTCL-PGCONNDEFAULTS">
<REFMETA>
<REFENTRYTITLE>pg_conndefaults</REFENTRYTITLE>
<REFMISCINFO>PGTCL - Connection Management</REFMISCINFO>
</REFMETA>
<REFNAMEDIV>
<REFNAME>pg_conndefaults
</REFNAME>
<REFPURPOSE>obtain information about default connection parameters
</REFPURPOSE>
<INDEXTERM ID="IX-PGTCL-PGCONNDEFAULTS-1"><PRIMARY>pgtcl</PRIMARY><SECONDARY>connecting</SECONDARY></INDEXTERM>
<INDEXTERM ID="IX-PGTCL-PGCONNDEFAULTS-2"><PRIMARY>pg_conndefaults</PRIMARY></INDEXTERM>
</REFNAMEDIV>
<REFSYNOPSISDIV>
<REFSYNOPSISDIVINFO>
<DATE>1998-10-07</DATE>
</REFSYNOPSISDIVINFO>
<SYNOPSIS>
pg_conndefaults
</SYNOPSIS>
<REFSECT2 ID="R2-PGTCL-PGCONNDEFAULTS-1">
<REFSECT2INFO>
<DATE>1998-10-07</DATE>
</REFSECT2INFO>
<TITLE>Inputs
</TITLE>
<PARA>
None.
</PARA>
</REFSECT2>
<REFSECT2 ID="R2-PGTCL-PGCONNDEFAULTS-2">
<REFSECT2INFO>
<DATE>1998-10-07</DATE>
</REFSECT2INFO>
<TITLE>Outputs
</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">option list</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
The result is a list describing the possible connection options and their
current default values.
Each entry in the list is a sublist of the format:
<para>
{optname label dispchar dispsize value}
<Para>
where the optname is usable as an option in pg_connect -conninfo.
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
</REFSECT2>
</REFSYNOPSISDIV>
<REFSECT1 ID="R1-PGTCL-PGCONNDEFAULTS-1">
<REFSECT1INFO>
<DATE>1998-10-07</DATE>
</REFSECT1INFO>
<TITLE>Description
</TITLE>
<FUNCTION>pg_conndefaults</FUNCTION> returns info about the connection
options available in <FUNCTION>pg_connect -conninfo</FUNCTION> and the
current default value for each option.
</PARA>
</REFSECT1>
<REFSECT1 ID="R1-PGTCL-PGCONNDEFAULTS-2">
<TITLE>Usage
</TITLE>
<PARA>pg_conndefaults
</PARA>
</REFSECT1>
</REFENTRY>
<REFENTRY ID="PGTCL-PGEXEC">
<REFMETA>
<REFENTRYTITLE>pg_exec</REFENTRYTITLE>
<REFMISCINFO>PGTCL - Connection Management</REFMISCINFO>
<REFMISCINFO>PGTCL - Query Processing</REFMISCINFO>
</REFMETA>
<REFNAMEDIV>
<REFNAME>pg_exec
@ -399,11 +512,14 @@ pg_exec <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLASS
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">queryHandle</REPLACEABLE>
<REPLACEABLE CLASS="PARAMETER">resultHandle</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
the return result is either an error message or a handle for a query result.
A Tcl error will be returned if Pgtcl was unable to obtain a backend
response. Otherwise, a query result object is created and a handle for
it is returned. This handle can be passed to <FUNCTION>pg_result</FUNCTION>
to obtain the results of the query.
</PARA>
</LISTITEM>
</VARLISTENTRY>
@ -421,116 +537,240 @@ pg_exec <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLASS
Query result handles start with the connection handle and add a period
and a result number.
<PARA>
Note that lack of a Tcl error is not proof that the query succeeded!
An error message returned by the backend will be processed
as a query result with failure status, not by generating a Tcl error
in pg_exec.
</PARA>
</REFSECT1>
<REFENTRY ID="PGTCL-PGLISTEN">
<REFENTRY ID="PGTCL-PGRESULT">
<REFMETA>
<REFENTRYTITLE>pg_listen</REFENTRYTITLE>
<REFMISCINFO>PGTCL - Asynchronous Notify</REFMISCINFO>
<REFENTRYTITLE>pg_result</REFENTRYTITLE>
<REFMISCINFO>PGTCL - Query Processing</REFMISCINFO>
</REFMETA>
<REFNAMEDIV>
<REFNAME>pg_listen
<REFNAME>pg_result
</REFNAME>
<REFPURPOSE>sets or changes a callback for asynchronous NOTIFY messages
<REFPURPOSE>
get information about a query result
</REFPURPOSE>
<INDEXTERM ID="IX-PGTCL-PGLISTEN-1"><PRIMARY>pgtcl</PRIMARY><SECONDARY>notify</SECONDARY></INDEXTERM>
<INDEXTERM ID="IX-PGTCL-PGLISTEN-2"><PRIMARY>notify</PRIMARY></INDEXTERM>
<INDEXTERM ID="IX-PGTCL-PGRESULT-1"><PRIMARY>pgtcl</PRIMARY><SECONDARY>connecting</SECONDARY></INDEXTERM>
<INDEXTERM ID="IX-PGTCL-PGRESULT-2"><PRIMARY>pg_connect</PRIMARY></INDEXTERM>
</REFNAMEDIV>
<REFSYNOPSISDIV>
<REFSYNOPSISDIVINFO>
<DATE>1998-5-22</DATE>
<DATE>1997-12-24</DATE>
</REFSYNOPSISDIVINFO>
<SYNOPSIS>
pg_listen <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLASS="PARAMETER">notifyName</REPLACEABLE> <REPLACEABLE CLASS="PARAMETER">callbackCommand</REPLACEABLE>
pg_result <REPLACEABLE CLASS="PARAMETER">resultHandle</REPLACEABLE> <REPLACEABLE CLASS="PARAMETER">resultOption</REPLACEABLE>
</SYNOPSIS>
<REFSECT2 ID="R2-PGTCL-PGLISTEN-1">
<REFSECT2 ID="R2-PGTCL-PGRESULT-1">
<REFSECT2INFO>
<DATE>1998-5-22</DATE>
<DATE>1997-12-24</DATE>
</REFSECT2INFO>
<TITLE>Inputs
</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>Specifies a valid database handle.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">notifyName</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>Specifies the notification name to start or stop listening to.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">callbackCommand</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>If present and not empty, provides the command string to execute
when a matching notification arrives.
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
</REFSECT2>
<REFSECT2 ID="R2-PGTCL-PGLISTEN-2">
<REFSECT2INFO>
<DATE>1998-5-22</DATE>
</REFSECT2INFO>
<TITLE>Outputs
</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
None
<REPLACEABLE CLASS="PARAMETER">resultHandle</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
The handle for a query result.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">resultOption</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
Specifies one of several possible options.
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
</REFSECT2>
</REFSYNOPSISDIV>
<REFSECT1 ID="R1-PGTCL-PGLISTEN-1">
<REFSECT3>
<TITLE>Options</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
-status
</TERM>
<LISTITEM>
<PARA>
the status of the result.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-error
</TERM>
<LISTITEM>
<PARA>
the error message, if the status indicates error; otherwise an empty string.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-conn
</TERM>
<LISTITEM>
<PARA>
the connection that produced the result.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-oid
</TERM>
<LISTITEM>
<PARA>
if the command was an INSERT, the OID of the
inserted tuple; otherwise an empty string.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-numTuples
</TERM>
<LISTITEM>
<PARA>
the number of tuples returned by the query.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-numAttrs
</TERM>
<LISTITEM>
<PARA>
the number of attributes in each tuple.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-assign arrayName
</TERM>
<LISTITEM>
<PARA>
assign the results to an array, using subscripts of the form
(tupno,attributeName).
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-assignbyidx arrayName ?appendstr?
</TERM>
<LISTITEM>
<PARA>
assign the results to an array using the first attribute's value and
the remaining attributes' names as keys. If appendstr is given then
it is appended to each key. In short, all but the first field of each
tuple are stored into the array, using subscripts of the form
(firstFieldValue,fieldNameAppendStr).
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-getTuple tupleNumber
</TERM>
<LISTITEM>
<PARA>
returns the fields of the indicated tuple in a list. Tuple numbers
start at zero.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-tupleArray tupleNumber arrayName
</TERM>
<LISTITEM>
<PARA>
stores the fields of the tuple in array arrayName, indexed by field names.
Tuple numbers start at zero.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-attributes
</TERM>
<LISTITEM>
<PARA>
returns a list of the names of the tuple attributes.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-lAttributes
</TERM>
<LISTITEM>
<PARA>
returns a list of sublists, {name ftype fsize} for each tuple attribute.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-clear
</TERM>
<LISTITEM>
<PARA>
clear the result query object.
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
</REFSECT3>
</REFSECT2>
<REFSECT2 ID="R2-PGTCL-PGRESULT-2">
<REFSECT2INFO>
<DATE>1997-12-24</DATE>
</REFSECT2INFO>
<TITLE>Outputs
</TITLE>
<PARA>
The result depends on the selected option, as described above.
</PARA>
</REFSECT2></REFSYNOPSISDIV>
<REFSECT1 ID="R1-PGTCL-PGRESULT-1">
<REFSECT1INFO>
<DATE>1998-5-22</DATE>
<DATE>1997-12-24</DATE>
</REFSECT1INFO>
<TITLE>Description
</TITLE>
<PARA><FUNCTION>pg_listen</FUNCTION> creates, changes, or cancels a request
to listen for asynchronous NOTIFY messages from the
<ProductName>Postgres</ProductName> backend. With a callbackCommand
parameter, the request is established, or the command string of an already
existing request is replaced. With no callbackCommand parameter, a prior
request is canceled.
</PARA>
<PARA>
<FUNCTION>pg_result</FUNCTION> returns information about a query result
created by a prior <FUNCTION>pg_exec</FUNCTION>.
<para>
After a <PARA><FUNCTION>pg_listen</FUNCTION> request is established,
the specified command string is executed whenever a NOTIFY message bearing
the given name arrives from the backend. This occurs when any
<ProductName>Postgres</ProductName> client application issues a NOTIFY command
referencing that name. (Note that the name can be, but does not have to be,
that of an existing relation in the database.)
The command string is executed from the Tcl idle loop. That is the normal
idle state of an application written with Tk. In non-Tk Tcl shells, you can
execute <FUNCTION>update</FUNCTION> or <FUNCTION>vwait</FUNCTION> to cause
the idle loop to be entered.
You can keep a query result around for as long as you need it, but when
you are done with it, be sure to free it by
executing <FUNCTION>pg_result -clear</FUNCTION>. Otherwise, you have
a memory leak, and Pgtcl will eventually start complaining that you've
created too many query result objects.
</PARA>
</REFSECT1>
</REFENTRY>
<!-- ********************************************************** -->
@ -538,7 +778,7 @@ the idle loop to be entered.
<REFENTRY ID="PGTCL-PGSELECT">
<REFMETA>
<REFENTRYTITLE>pg_select</REFENTRYTITLE>
<REFMISCINFO>PGTCL - Connection Management</REFMISCINFO>
<REFMISCINFO>PGTCL - Query Processing</REFMISCINFO>
</REFMETA>
<REFNAMEDIV>
<REFNAME>pg_select
@ -614,7 +854,7 @@ pg_select <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLA
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">queryHandle</REPLACEABLE>
<REPLACEABLE CLASS="PARAMETER">resultHandle</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
@ -632,14 +872,18 @@ pg_select <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLA
<TITLE>Description
</TITLE>
<PARA>
<FUNCTION>pg_select</FUNCTION> submits a query to the <ProductName>Postgres</ProductName> backend.
and returns the results.
<FUNCTION>pg_select</FUNCTION> submits a SELECT query to the
<ProductName>Postgres</ProductName> backend, and executes a
given chunk of code for each tuple in the result.
The <REPLACEABLE CLASS="PARAMETER">queryString</REPLACEABLE>
must be a select statement. Anything else returns an error.
must be a SELECT statement. Anything else returns an error.
The <REPLACEABLE CLASS="PARAMETER">arrayVar</REPLACEABLE>
variable is an array name used in the loop. It is filled
out with the result of the query for each tuple using the field
names as the associative indices.
variable is an array name used in the loop. For each tuple,
<REPLACEABLE CLASS="PARAMETER">arrayVar</REPLACEABLE> is filled in
with the tuple field values, using the field names as the array
indexes. Then the
<REPLACEABLE CLASS="PARAMETER">queryProcedure</REPLACEABLE>
is executed.
</PARA>
</REFSECT1>
@ -647,13 +891,12 @@ pg_select <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLA
<TITLE>Usage
</TITLE>
<PARA>
This would work if table "table" has fields "control" and "name"
(and, perhaps, other fields):
<ProgramListing>
set DB "mydb"
set conn [pg_connect $DB]
pg_select $conn "SELECT * from table" array {
pg_select $pgconn "SELECT * from table" array {
puts [format "%5d %s" array(control) array(name)]
}
pg_disconnect $conn
</ProgramListing>
</PARA>
</REFSECT1>
@ -662,187 +905,119 @@ pg_select <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLA
<!-- ********************************************************** -->
<REFENTRY ID="PGTCL-PGRESULT">
<REFENTRY ID="PGTCL-PGLISTEN">
<REFMETA>
<REFENTRYTITLE>pg_result</REFENTRYTITLE>
<REFMISCINFO>PGTCL - Connection Management</REFMISCINFO>
<REFENTRYTITLE>pg_listen</REFENTRYTITLE>
<REFMISCINFO>PGTCL - Asynchronous Notify</REFMISCINFO>
</REFMETA>
<REFNAMEDIV>
<REFNAME>pg_result
<REFNAME>pg_listen
</REFNAME>
<REFPURPOSE>
get information about a query result
<REFPURPOSE>sets or changes a callback for asynchronous NOTIFY messages
</REFPURPOSE>
<INDEXTERM ID="IX-PGTCL-PGRESULT-1"><PRIMARY>pgtcl</PRIMARY><SECONDARY>connecting</SECONDARY></INDEXTERM>
<INDEXTERM ID="IX-PGTCL-PGRESULT-2"><PRIMARY>pg_connect</PRIMARY></INDEXTERM>
<INDEXTERM ID="IX-PGTCL-PGLISTEN-1"><PRIMARY>pgtcl</PRIMARY><SECONDARY>notify</SECONDARY></INDEXTERM>
<INDEXTERM ID="IX-PGTCL-PGLISTEN-2"><PRIMARY>notify</PRIMARY></INDEXTERM>
</REFNAMEDIV>
<REFSYNOPSISDIV>
<REFSYNOPSISDIVINFO>
<DATE>1997-12-24</DATE>
<DATE>1998-5-22</DATE>
</REFSYNOPSISDIVINFO>
<SYNOPSIS>
pg_result <REPLACEABLE CLASS="PARAMETER">queryHandle</REPLACEABLE> <REPLACEABLE CLASS="PARAMETER">resultOption</REPLACEABLE>
pg_listen <REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE> <REPLACEABLE CLASS="PARAMETER">notifyName</REPLACEABLE> <REPLACEABLE CLASS="PARAMETER">callbackCommand</REPLACEABLE>
</SYNOPSIS>
<REFSECT2 ID="R2-PGTCL-PGRESULT-1">
<REFSECT2 ID="R2-PGTCL-PGLISTEN-1">
<REFSECT2INFO>
<DATE>1997-12-24</DATE>
<DATE>1998-5-22</DATE>
</REFSECT2INFO>
<TITLE>Inputs
</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">queryHandle</REPLACEABLE>
<REPLACEABLE CLASS="PARAMETER">dbHandle</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
The handle for a query result.
<PARA>Specifies a valid database handle.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">resultOption</REPLACEABLE>
<REPLACEABLE CLASS="PARAMETER">notifyName</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>
Specifies one of several possible options.
<PARA>Specifies the notify condition name to start or stop listening to.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">callbackCommand</REPLACEABLE>
</TERM>
<LISTITEM>
<PARA>If present and not empty, provides the command string to execute
when a matching notification arrives.
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
<REFSECT3>
<TITLE>Options</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
-status
</TERM>
<LISTITEM>
<PARA>
the status of the result.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-oid
</TERM>
<LISTITEM>
<PARA>
if the last query was an insert, returns the oid of the
inserted tuple
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-conn
</TERM>
<LISTITEM>
<PARA>
the connection that produced the result
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-assign arrayName
</TERM>
<LISTITEM>
<PARA>
assign the results to an array
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-assignbyidx arrayName ?appendstr?
</TERM>
<LISTITEM>
<PARA>
assign the results to an array using the first field as a key
and optionally append appendstr to the key name. Useful for
creating pseudo-multi dimensional arrays in tcl.
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-numTuples
</TERM>
<LISTITEM>
<PARA>
the number of tuples in the query
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-attributes
</TERM>
<LISTITEM>
<PARA>
returns a list of the name/type pairs of the tuple attributes
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-getTuple tupleNumber
</TERM>
<LISTITEM>
<PARA>
returns the values of the tuple in a list
</PARA>
</LISTITEM>
</VARLISTENTRY>
<VARLISTENTRY>
<TERM>
-clear
</TERM>
<LISTITEM>
<PARA>
clear the result buffer. Do not reuse after this
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
</REFSECT3>
</REFSECT2>
<REFSECT2 ID="R2-PGTCL-PGRESULT-2">
<REFSECT2 ID="R2-PGTCL-PGLISTEN-2">
<REFSECT2INFO>
<DATE>1997-12-24</DATE>
<DATE>1998-5-22</DATE>
</REFSECT2INFO>
<TITLE>Outputs
</TITLE>
<VARIABLELIST>
<VARLISTENTRY>
<TERM>
<REPLACEABLE CLASS="PARAMETER">queryHandle</REPLACEABLE>
None
</TERM>
<LISTITEM>
<PARA>
the return result is either an error message or a handle for a query result.
</PARA>
</LISTITEM>
</VARLISTENTRY>
</VARIABLELIST>
</REFSECT2></REFSYNOPSISDIV>
</REFSECT2>
</REFSYNOPSISDIV>
<REFSECT1 ID="R1-PGTCL-PGRESULT-1">
<REFSECT1 ID="R1-PGTCL-PGLISTEN-1">
<REFSECT1INFO>
<DATE>1997-12-24</DATE>
<DATE>1998-5-22</DATE>
</REFSECT1INFO>
<TITLE>Description
</TITLE>
<PARA>
<FUNCTION>pg_result</FUNCTION> returns information about a query.
<PARA><FUNCTION>pg_listen</FUNCTION> creates, changes, or cancels a request
to listen for asynchronous NOTIFY messages from the
<ProductName>Postgres</ProductName> backend. With a callbackCommand
parameter, the request is established, or the command string of an already
existing request is replaced. With no callbackCommand parameter, a prior
request is canceled.
</PARA>
<para>
After a <FUNCTION>pg_listen</FUNCTION> request is established,
the specified command string is executed whenever a NOTIFY message bearing
the given name arrives from the backend. This occurs when any
<ProductName>Postgres</ProductName> client application issues a NOTIFY command
referencing that name. (Note that the name can be, but does not have to be,
that of an existing relation in the database.)
The command string is executed from the Tcl idle loop. That is the normal
idle state of an application written with Tk. In non-Tk Tcl shells, you can
execute <FUNCTION>update</FUNCTION> or <FUNCTION>vwait</FUNCTION> to cause
the idle loop to be entered.
<para>
You should not invoke the SQL statements LISTEN or UNLISTEN directly when
using <FUNCTION>pg_listen</FUNCTION>. Pgtcl takes care of issuing those
statements for you. But if you want to send a NOTIFY message yourself,
invoke the SQL NOTIFY statement using <FUNCTION>pg_exec</FUNCTION>.
</PARA>
</REFSECT1>
</REFENTRY>
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