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Clean up sql functions examples.

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This commit is contained in:
Bruce Momjian 2000-05-20 11:24:37 +00:00
parent a9876533d6
commit c99e851eea
1 changed files with 41 additions and 28 deletions
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69
doc/src/sgml/xfunc.sgml
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@ -1,5 +1,5 @@
<!--
$Header: /cvsroot/pgsql/doc/src/sgml/xfunc.sgml,v 1.15 2000/05/18 14:24:32 momjian Exp $
$Header: /cvsroot/pgsql/doc/src/sgml/xfunc.sgml,v 1.16 2000/05/20 11:24:37 momjian Exp $
-->
<chapter id="xfunc">
@ -87,11 +87,13 @@ $Header: /cvsroot/pgsql/doc/src/sgml/xfunc.sgml,v 1.15 2000/05/18 14:24:32 momji
which might be used to debit a bank account:
<programlisting>
create function TP1 (int4, float8) returns int4
as 'update BANK set balance = BANK.balance - $2
where BANK.acctountno = $1
select(x = 1)'
language 'sql';
CREATE FUNCTION tp1 (int4, float8)
RETURNS int4
AS ' UPDATE bank
SET balance = bank.balance - $2
WHERE bank.acctountno = $1;
SELECT 1;'
LANGUAGE 'sql';
</programlisting>
A user could execute this function to debit account 17 by $100.00 as
@ -108,7 +110,7 @@ select (x = TP1( 17,100.0));
<programlisting>
select function hobbies (EMP) returns set of HOBBIES
as 'select (HOBBIES.all) from HOBBIES
as 'select HOBBIES.* from HOBBIES
where $1.name = HOBBIES.person'
language 'sql';
</programlisting>
@ -123,8 +125,10 @@ select function hobbies (EMP) returns set of HOBBIES
simply returns a base type, such as <literal>int4</literal>:
<programlisting>
CREATE FUNCTION one() RETURNS int4
AS 'SELECT 1 as RESULT' LANGUAGE 'sql';
CREATE FUNCTION one()
RETURNS int4
AS 'SELECT 1 as RESULT;'
LANGUAGE 'sql';
SELECT one() AS answer;
@ -149,8 +153,10 @@ SELECT one() AS answer;
and $2:
<programlisting>
CREATE FUNCTION add_em(int4, int4) RETURNS int4
AS 'SELECT $1 + $2;' LANGUAGE 'sql';
CREATE FUNCTION add_em(int4, int4)
RETURNS int4
AS 'SELECT $1 + $2;'
LANGUAGE 'sql';
SELECT add_em(1, 2) AS answer;
@ -175,12 +181,14 @@ SELECT add_em(1, 2) AS answer;
salary would be if it were doubled:
<programlisting>
CREATE FUNCTION double_salary(EMP) RETURNS int4
AS 'SELECT $1.salary * 2 AS salary;' LANGUAGE 'sql';
CREATE FUNCTION double_salary(EMP)
RETURNS int4
AS 'SELECT $1.salary * 2 AS salary;'
LANGUAGE 'sql';
SELECT name, double_salary(EMP) AS dream
FROM EMP
WHERE EMP.cubicle ~= '(2,1)'::point;
FROM EMP
WHERE EMP.cubicle ~= '(2,1)'::point;
+-----+-------+
@ -223,12 +231,13 @@ SELECT name(EMP) AS youngster
that returns a single EMP instance:
<programlisting>
CREATE FUNCTION new_emp() RETURNS EMP
AS 'SELECT \'None\'::text AS name,
1000 AS salary,
25 AS age,
\'(2,2)\'::point AS cubicle'
LANGUAGE 'sql';
CREATE FUNCTION new_emp()
RETURNS EMP
AS ' SELECT \'None\'::text AS name,
1000 AS salary,
25 AS age,
\'(2,2)\'::point AS cubicle'
LANGUAGE 'sql';
</programlisting>
</para>
<para>
@ -303,10 +312,12 @@ NOTICE:parser: syntax error at or near "."
specified as the function's returntype.
<programlisting>
CREATE FUNCTION clean_EMP () RETURNS int4
AS 'DELETE FROM EMP WHERE EMP.salary &lt;= 0;
SELECT 1 AS ignore_this'
LANGUAGE 'sql';
CREATE FUNCTION clean_EMP ()
RETURNS int4
AS ' DELETE FROM EMP
WHERE EMP.salary &lt;= 0;
SELECT 1 AS ignore_this;'
LANGUAGE 'sql';
SELECT clean_EMP();
@ -837,8 +848,10 @@ str = (char *) GetAttributeByName(t, "name", &amp;isnull)
know about the c_overpaid function:
<programlisting>
* CREATE FUNCTION c_overpaid(EMP, int4) RETURNS bool
AS '<replaceable>PGROOT</replaceable>/tutorial/obj/funcs.so' LANGUAGE 'c';
CREATE FUNCTION c_overpaid(EMP, int4)
RETURNS bool
AS '<replaceable>PGROOT</replaceable>/tutorial/obj/funcs.so'
LANGUAGE 'c';
</programlisting>
</para>
@ -999,7 +1012,7 @@ str = (char *) GetAttributeByName(t, "name", &amp;isnull)
<para>
For functions written in C, the SQL name declared in
<command>CREATE FUNCTION</command>
<command>CREATE FUNC TION</command>
must be exactly the same as the actual name of the function in the
C code (hence it must be a legal C function name).
</para>