1  LOOP_Control
   Allows the repetitive execution of one or more SQL statements in
   a compound statement.

   See also the FOR, REPEAT and WHILE statements.
 

2  Environment
   You can use the LOOP control statement only within a compound
   statement:

   o  In interactive SQL

   o  Embedded in host language programs to be precompiled

   o  As part of a procedure in an SQL module

   o  In dynamic SQL as a statement to be dynamically executed
 

2  Format

 loop-statement =
 
 ---+-----------------------+-------------------+
    +-> <beginning-label> : +                   |
    +-------------------------------------------+
    +-> LOOP --+-> compound-use-statement -+---+
               +-------------<-------------+   |
    +------------------------------------------+
    +-> END LOOP --+------------------+->
                   +-> <ending-label> +
 



 compound-use-statement =
 
 ----+-> call-statement --------------+--> ;
     +-> commit-statement ------------+
     +-> control-statement -----------+
     +-> delete-statement ------------+
     +-> get-diagnostics-statement ---+
     +-> insert-statement ------------+
     +-> lock-table-statement --------+
     +-> rollback-statement ----------+
     +-> set-transaction-statement ---+
     +-> singleton-select-statement --+
     +-> start-transaction-statement -+
     +-> trace-statement -------------+
     +-> update-statement ------------+

 

2  Arguments
 

3  beginning-label

   Assigns a name to a control loop. A beginning label used with the
   LEAVE statement lets you perform a controlled exit from a loop. A
   named loop is called a labeled loop statement. If you include an
   ending label, it must be identical to its corresponding beginning
   label. A beginning label must be unique within the procedure in
   which the label is contained.
 

3  compound-use-statement

   Identifies the SQL statements allowed in a compound statement
   block. See the Compound_Statement HELP topic for the list of
   valid statements.
 

3  END_LOOP

   Marks the end of a control loop. If you choose to include the
   optional ending label, it must match exactly its corresponding
   beginning label. An ending label must be unique within the
   procedure in which the label is contained.

   The optional end-label argument makes multistatement procedures
   easier to read, especially in very complex multistatement
   procedure blocks.
 

3  LOOP

   Marks the start of a control loop. A LOOP statement enables you
   to execute the associated sequence of SQL statements called a
   compound statement. After SQL executes the statements within the
   loop, control returns to the LOOP statement at the top of the
   loop for subsequent statement execution. Looping occurs until
   SQL encounters an error exception or executes a LEAVE statement.
   In either case, SQL passes control out of the LOOP block to the
   statement immediately after the LOOP statement.
 

2  Examples
   Example 1: Executing a loop statement

   SQL> create table ENROLLMENTS
   cont>     (last_name          char(20),
   cont>      first_name         char(10),
   cont>      middle_initial     char,
   cont>      class_name         char(10));
   SQL>
   SQL> begin
   cont> declare :n integer default 5;
   cont> loop
   cont>     insert into ENROLLMENTS
   cont>       values ('Jones', 'Robert', 'A',
   cont>               'Class ' || CAST(:n as char(1)));
   cont>     set :n = :n - 1;
   cont>     if :n <= 0 then
   cont>         leave;
   cont>     end if;
   cont> end loop;
   cont> end;
   SQL>
   SQL> select * from ENROLLMENTS;
    LAST_NAME              FIRST_NAME   MIDDLE_INITIAL   CLASS_NAME
    Jones                  Robert       A                Class 5
    Jones                  Robert       A                Class 4
    Jones                  Robert       A                Class 3
    Jones                  Robert       A                Class 2
    Jones                  Robert       A                Class 1
   5 rows selected
   SQL>