IBM DB2 Control Loop

Question

I am migrating from MS SQL Server to IBM DB2 (Version 9.7). Trying to write a compound SQL While Loop with local variables (Not a part of Stored Procedure), something like -

BEGIN ATOMIC
   DECLARE i INT DEFAULT 12;
     WHILE i > 0 
     "DO ....";
     SET COUNT = COUNT - 1;
     END WHILE;
 END

But I get an error just in first line for declaring variables-

SQL0104N  An unexpected token "12" was found following "ECLARE I INT DEFAULT". Expected tokens may include:  "END-OF-STATEMENT"

Any help is greatly appreciated.

Answer 1

I assume that your problem has to do with statement terminator (easier to see if you provide the actual errors you get). I tested the following and it worked:

[ ... ]$ cat aa.sql 

CREATE TABLE TEMP_ITERATIONS ( X VARCHAR(50) ) @

BEGIN ATOMIC 
    DECLARE i INT DEFAULT 12; 
    WHILE i > 0 DO 
        INSERT INTO TEMP_ITERATIONS VALUES ('IT'|| RTRIM(CHAR(i))); 
        SET i = i - 1; 
    END WHILE; 
END @

[ ... ]$ db2 -td@ -f aa.sql

DB20000I  The SQL command completed successfully.
DB20000I  The SQL command completed successfully.

[ ... ]$ db2 "select * from TEMP_ITERATIONS"

X                                                 
--------------------------------------------------
IT12                                              
IT11                                              
IT10
[...]
12 record(s) selected.

Here I used @ as a statement terminator since ; has a special meaning. If you don't want to change the statement terminator a trick is to "hide" the ; inside the compound statement by adding a comment at the end of the line:

[ ... ]$ cat aa.sql 

CREATE TABLE TEMP_ITERATIONS ( X VARCHAR(50) ) ;

BEGIN ATOMIC 
    DECLARE i INT DEFAULT 12; --
    WHILE i > 0 DO 
        INSERT INTO TEMP_ITERATIONS VALUES ('IT'|| RTRIM(CHAR(i))); --
        SET i = i - 1; --
    END WHILE; --
END ;

[ ... ] db2 -tf aa.sql
DB20000I  The SQL command completed successfully.
DB20000I  The SQL command completed successfully.

[ ... ]$ db2 "select * from TEMP_ITERATIONS"

X                                                 
--------------------------------------------------
IT12                                              
IT11                                              
IT10
[...]
12 record(s) selected.