Add CREATE DATABASE LOCALE option

This sets both LC_COLLATE and LC_CTYPE with one option.  Similar
behavior is already supported in initdb, CREATE COLLATION, and
createdb.

Reviewed-by: Fabien COELHO <coelho@cri.ensmp.fr>
Discussion: https://www.postgresql.org/message-id/flat/d9d5043a-dc70-da8a-0166-1e218e6e34d4%402ndquadrant.com

doc/src/sgml/ref/create_database.sgml

@@ -25,6 +25,7 @@ CREATE DATABASE <replaceable class="parameter">name</replaceable>
     [ [ WITH ] [ OWNER [=] <replaceable class="parameter">user_name</replaceable> ]
            [ TEMPLATE [=] <replaceable class="parameter">template</replaceable> ]
            [ ENCODING [=] <replaceable class="parameter">encoding</replaceable> ]
+           [ LOCALE [=] <replaceable class="parameter">locale</replaceable> ]
            [ LC_COLLATE [=] <replaceable class="parameter">lc_collate</replaceable> ]
            [ LC_CTYPE [=] <replaceable class="parameter">lc_ctype</replaceable> ]
            [ TABLESPACE [=] <replaceable class="parameter">tablespace_name</replaceable> ]
@@ -111,6 +112,26 @@ CREATE DATABASE <replaceable class="parameter">name</replaceable>
        </para>
       </listitem>
      </varlistentry>
+     <varlistentry>
+      <term><replaceable class="parameter">locale</replaceable></term>
+      <listitem>
+       <para>
+        This is a shortcut for setting <symbol>LC_COLLATE</symbol>
+        and <symbol>LC_CTYPE</symbol> at once.  If you specify this,
+        you cannot specify either of those parameters.
+       </para>
+       <tip>
+        <para>
+         The other locale settings <xref linkend="guc-lc-messages"/>, <xref
+         linkend="guc-lc-monetary"/>, <xref linkend="guc-lc-numeric"/>, and
+         <xref linkend="guc-lc-time"/> are not fixed per database and are not
+         set by this command.  If you want to make them the default for a
+         specific database, you can use <literal>ALTER DATABASE
+         ... SET</literal>.
+        </para>
+       </tip>
+      </listitem>
+     </varlistentry>
      <varlistentry>
       <term><replaceable class="parameter">lc_collate</replaceable></term>
       <listitem>
@@ -287,7 +308,7 @@ CREATE DATABASE sales OWNER salesapp TABLESPACE salesspace;
    To create a database <literal>music</literal> with a different locale:
 <programlisting>
 CREATE DATABASE music
-    LC_COLLATE 'sv_SE.utf8' LC_CTYPE 'sv_SE.utf8'
+    LOCALE 'sv_SE.utf8'
     TEMPLATE template0;
 </programlisting>
     In this example, the <literal>TEMPLATE template0</literal> clause is required if
@@ -300,7 +321,7 @@ CREATE DATABASE music
    different character set encoding:
 <programlisting>
 CREATE DATABASE music2
-    LC_COLLATE 'sv_SE.iso885915' LC_CTYPE 'sv_SE.iso885915'
+    LOCALE 'sv_SE.iso885915'
     ENCODING LATIN9
     TEMPLATE template0;
 </programlisting>

src/backend/commands/dbcommands.c

@@ -124,6 +124,7 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 	DefElem    *downer = NULL;
 	DefElem    *dtemplate = NULL;
 	DefElem    *dencoding = NULL;
+	DefElem    *dlocale = NULL;
 	DefElem    *dcollate = NULL;
 	DefElem    *dctype = NULL;
 	DefElem    *distemplate = NULL;
@@ -184,6 +185,15 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 						 parser_errposition(pstate, defel->location)));
 			dencoding = defel;
 		}
+		else if (strcmp(defel->defname, "locale") == 0)
+		{
+			if (dlocale)
+				ereport(ERROR,
+						(errcode(ERRCODE_SYNTAX_ERROR),
+						 errmsg("conflicting or redundant options"),
+						 parser_errposition(pstate, defel->location)));
+			dlocale = defel;
+		}
 		else if (strcmp(defel->defname, "lc_collate") == 0)
 		{
 			if (dcollate)
@@ -244,6 +254,12 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 					 parser_errposition(pstate, defel->location)));
 	}
 
+	if (dlocale && (dcollate || dctype))
+		ereport(ERROR,
+				(errcode(ERRCODE_SYNTAX_ERROR),
+				 errmsg("conflicting or redundant options"),
+				 errdetail("LOCALE cannot be specified together with LC_COLLATE or LC_CTYPE.")));
+
 	if (downer && downer->arg)
 		dbowner = defGetString(downer);
 	if (dtemplate && dtemplate->arg)
@@ -276,6 +292,11 @@ createdb(ParseState *pstate, const CreatedbStmt *stmt)
 						 parser_errposition(pstate, dencoding->location)));
 		}
 	}
+	if (dlocale && dlocale->arg)
+	{
+		dbcollate = defGetString(dlocale);
+		dbctype = defGetString(dlocale);
+	}
 	if (dcollate && dcollate->arg)
 		dbcollate = defGetString(dcollate);
 	if (dctype && dctype->arg)

src/bin/pg_dump/pg_dump.c

@@ -2812,15 +2812,23 @@ dumpDatabase(Archive *fout)
 		appendPQExpBufferStr(creaQry, " ENCODING = ");
 		appendStringLiteralAH(creaQry, encoding, fout);
 	}
-	if (strlen(collate) > 0)
+	if (strlen(collate) > 0 && strcmp(collate, ctype) == 0)
 	{
-		appendPQExpBufferStr(creaQry, " LC_COLLATE = ");
+		appendPQExpBufferStr(creaQry, " LOCALE = ");
 		appendStringLiteralAH(creaQry, collate, fout);
 	}
-	if (strlen(ctype) > 0)
+	else
 	{
-		appendPQExpBufferStr(creaQry, " LC_CTYPE = ");
-		appendStringLiteralAH(creaQry, ctype, fout);
+		if (strlen(collate) > 0)
+		{
+			appendPQExpBufferStr(creaQry, " LC_COLLATE = ");
+			appendStringLiteralAH(creaQry, collate, fout);
+		}
+		if (strlen(ctype) > 0)
+		{
+			appendPQExpBufferStr(creaQry, " LC_CTYPE = ");
+			appendStringLiteralAH(creaQry, ctype, fout);
+		}
 	}
 
 	/*

src/bin/pg_dump/t/002_pg_dump.pl

@@ -1407,6 +1407,15 @@ my %tests = (
 		like => { pg_dumpall_dbprivs => 1, },
 	},
 
+	"CREATE DATABASE dump_test2 LOCALE = 'C'" => {
+		create_order => 47,
+		create_sql   => "CREATE DATABASE dump_test2 LOCALE = 'C' TEMPLATE = template0;",
+		regexp       => qr/^
+			\QCREATE DATABASE dump_test2 \E.*\QLOCALE = 'C';\E
+			/xm,
+		like => { pg_dumpall_dbprivs => 1, },
+	},
+
 	'CREATE EXTENSION ... plpgsql' => {
 		regexp => qr/^
 			\QCREATE EXTENSION IF NOT EXISTS plpgsql WITH SCHEMA pg_catalog;\E