提交 7d1d7200 编写于 作者: B Bruce Momjian

Minor doc patch: create function

Gavin Sherry
上级 ee303739
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$Header: /cvsroot/pgsql/doc/src/sgml/ref/create_function.sgml,v 1.44 2003/01/19 00:13:29 momjian Exp $ $Header: /cvsroot/pgsql/doc/src/sgml/ref/create_function.sgml,v 1.45 2003/03/20 04:41:13 momjian Exp $
--> -->
<refentry id="SQL-CREATEFUNCTION"> <refentry id="SQL-CREATEFUNCTION">
...@@ -66,18 +66,22 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable> ...@@ -66,18 +66,22 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
<listitem> <listitem>
<para> <para>
The data type(s) of the function's arguments, if any. The The data type(s) of the function's arguments (optionally
input types may be base, complex, or domain types, schema-qualified), if any. The input types may be base, complex, or
or the same as the type of an existing column. domain types, or the same as the type of an existing column.
The type of a column is referenced by writing <replaceable </para>
class="parameter">tablename</replaceable>.<replaceable <para>
class="parameter">columnname</replaceable><literal>%TYPE</literal>; The type of a column is referenced by writing <replaceable
using this can sometimes help make a function independent from class="parameter">tablename</replaceable>.<replaceable
changes to the definition of a table. class="parameter">columnname</replaceable><literal>%TYPE</literal>;
Depending on the implementation language it may also be allowed using this can sometimes help make a function independent from
to specify <quote>pseudo-types</> such as <type>cstring</>. changes to the definition of a table.
Pseudo-types indicate that the actual argument type is either </para>
incompletely specified, or outside the set of ordinary SQL data types. <para>
Depending on the implementation language it may also be allowed
to specify <quote>pseudo-types</> such as <type>cstring</>.
Pseudo-types indicate that the actual argument type is either
incompletely specified, or outside the set of ordinary SQL data types.
</para> </para>
</listitem> </listitem>
</varlistentry> </varlistentry>
...@@ -87,9 +91,13 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable> ...@@ -87,9 +91,13 @@ CREATE [ OR REPLACE ] FUNCTION <replaceable class="parameter">name</replaceable>
<listitem> <listitem>
<para> <para>
The return data type. The return type may be specified as a The return data type (optionally schema-qualified). The return type
base, complex, or domain type, or the same as the type of an may be specified as a base, complex, domain type
existing column. or the same as the type of an existing column. See the description
under <literal>argtype</literal> above on how to reference the type
of an existing column.
</para>
<para>
Depending on the implementation language it may also be allowed Depending on the implementation language it may also be allowed
to specify <quote>pseudo-types</> such as <type>cstring</>. to specify <quote>pseudo-types</> such as <type>cstring</>.
The <literal>setof</literal> The <literal>setof</literal>
...@@ -432,13 +440,13 @@ CREATE FUNCTION point(complex) RETURNS point ...@@ -432,13 +440,13 @@ CREATE FUNCTION point(complex) RETURNS point
<programlisting> <programlisting>
Point * complex_to_point (Complex *z) Point * complex_to_point (Complex *z)
{ {
Point *p; Point *p;
p = (Point *) palloc(sizeof(Point)); p = (Point *) palloc(sizeof(Point));
p->x = z->x; p->x = z->x;
p->y = z->y; p->y = z->y;
return p; return p;
} }
</programlisting> </programlisting>
......
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