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<HTML
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>Cursor Handling</A
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><P
> A cursor is a declares a SQL query with its input and result
parameters. The result set is created when the cursor is opened.
The syntax for declaring, opening and closing a cursor is shown
below.
</P
><PRE
CLASS="PROGRAMLISTING"
> 'DECLARE' <name> [ 'REOPENABLE' | 'LOCAL' ] 'CURSOR'
'FOR' <sql query>
'OPEN' <name>
'CLOSE' <name> ['FINAL']
</PRE
><P
> LOCAL cursors are only defined within the scope of the block
where the nearest DECLARE section is. If the scope is left,
the cursor and the associated result set are deleted.
</P
><DIV
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><B
>Example 11-4. Local Cursors</B
></P
><P
> As shown in the example below, the cursor emp_cursor will only be
valid in the scope of the procedure Print_Departement:
</P
><PRE
CLASS="PROGRAMLISTING"
> procedure Print_Departement( ..........
... departement : in Integer ) is
EXEC SQL BEGIN DECLARE SECTION ;
....
Depno : INT := INT( Departement );
....
EXEC SQL END DECLARE SECTION ;
begin
EXEC SQL AT DB01
DECLARE emp_cursor LOCAL CURSOR FOR
SELECT EMPNO, FIRSTNAME, NAME, JOB, MANAGER, SALARY
FROM employees
WHERE deptno = :Depno ORDER BY EMPNO, NAME;
.......
</PRE
></DIV
><P
> Normally it is not possible to open the same cursor twice. The
type REOPENABLE has been introduced, in order to allow the recursive
opening of cursors. This feature may also be emulated by means of
recursive procedures with local cursors.
</P
><P
> If the cursor type is omitted the cursor and its associated
result set to exist only once.
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