diff options
Diffstat (limited to 'doc/src/sgml/syntax.sgml')
| -rw-r--r-- | doc/src/sgml/syntax.sgml | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/doc/src/sgml/syntax.sgml b/doc/src/sgml/syntax.sgml index ae6ae9468dd..135fe7aca89 100644 --- a/doc/src/sgml/syntax.sgml +++ b/doc/src/sgml/syntax.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.103 2005/08/14 22:19:50 petere Exp $ +$PostgreSQL: pgsql/doc/src/sgml/syntax.sgml,v 1.104 2005/10/23 19:29:49 tgl Exp $ --> <chapter id="sql-syntax"> @@ -260,7 +260,7 @@ UPDATE "my_table" SET "a" = 5; <literal>\n</literal> is a newline, <literal>\r</literal> is a carriage return, <literal>\t</literal> is a tab. Also supported is <literal>\<replaceable>digits</replaceable></literal>, where - <replaceable>ddd</replaceable> represents an octal byte value, and + <replaceable>digits</replaceable> represents an octal byte value, and <literal>\x<replaceable>hexdigits</replaceable></literal>, where <replaceable>hexdigits</replaceable> represents a hexadecimal byte value. (It is your responsibility that the byte sequences you create are @@ -544,6 +544,16 @@ CAST ( '<replaceable>string</replaceable>' AS <replaceable>type</replaceable> ) is that it does not work for array types; use <literal>::</literal> or <literal>CAST()</literal> to specify the type of an array constant. </para> + + <para> + The <literal>CAST()</> syntax conforms to SQL. The + <literal><replaceable>type</replaceable> '<replaceable>string</replaceable>'</literal> + syntax is a generalization of the standard: SQL specifies this syntax only + for a few datatypes, but <productname>PostgreSQL</productname> allows it + for all types. The syntax with + <literal>::</literal> is historical <productname>PostgreSQL</productname> + usage, as is the function-call syntax. + </para> </sect3> </sect2> @@ -1105,8 +1115,8 @@ CREATE FUNCTION dept(text) RETURNS dept LANGUAGE SQL; </programlisting> - Here the <literal>$1</literal> will be replaced by the first - function argument when the function is invoked. + Here the <literal>$1</literal> references the value of the first + function argument whenever the function is invoked. </para> </sect2> |