diff options
Diffstat (limited to 'doc/src/sgml/ref/create_function.sgml')
| -rw-r--r-- | doc/src/sgml/ref/create_function.sgml | 30 |
1 files changed, 19 insertions, 11 deletions
diff --git a/doc/src/sgml/ref/create_function.sgml b/doc/src/sgml/ref/create_function.sgml index 8b29d830826..4929524cff4 100644 --- a/doc/src/sgml/ref/create_function.sgml +++ b/doc/src/sgml/ref/create_function.sgml @@ -1,5 +1,5 @@ <!-- -$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.55 2003/11/29 19:51:38 pgsql Exp $ +$PostgreSQL: pgsql/doc/src/sgml/ref/create_function.sgml,v 1.56 2004/05/16 23:22:07 neilc Exp $ --> <refentry id="SQL-CREATEFUNCTION"> @@ -54,10 +54,10 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable> To update the definition of an existing function, use <command>CREATE OR REPLACE FUNCTION</command>. It is not possible to change the name or argument types of a function this way (if you - tried, you'd just be creating a new, distinct function). Also, - <command>CREATE OR REPLACE FUNCTION</command> will not let you - change the return type of an existing function. To do that, you - must drop and recreate the function. + tried, you would actually be creating a new, distinct function). + Also, <command>CREATE OR REPLACE FUNCTION</command> will not let + you change the return type of an existing function. To do that, + you must drop and recreate the function. </para> <para> @@ -250,7 +250,14 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable> <para> A string defining the function; the meaning depends on the language. It may be an internal function name, the path to an - object file, an SQL command, or text in a procedural language. + object file, an SQL command, or text in a procedural + language. When this string contains the text of a procedural + language function definition, it may be helpful to use dollar + quoting to specify this string, rather than the normal single + quote syntax (this avoids the need to escape any single quotes + that occur in the function definition itself). For more + information on dollar quoting, see <xref + linkend="sql-syntax-strings">. </para> </listitem> </varlistentry> @@ -350,13 +357,14 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable> </para> <para> - Use <command>DROP FUNCTION</command> - to remove user-defined functions. + Use <xref linkend="sql-dropfunction" + endterm="sql-dropfunction-title"> to remove user-defined + functions. </para> <para> - Any single quotes or backslashes in the function definition must be - escaped by doubling them. + Unless dollar quoting is used, any single quotes or backslashes in + the function definition must be escaped by doubling them. </para> <para> @@ -374,7 +382,7 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable> information and examples, see <xref linkend="xfunc">. <programlisting> CREATE FUNCTION add(integer, integer) RETURNS integer - AS 'select $1 + $2;' + AS $$select $1 + $2;$$ LANGUAGE SQL IMMUTABLE RETURNS NULL ON NULL INPUT; |