Hi ,

I got struct over here , i am getting NULL when i am running this procedure ...I call one procedure , where it has a call to another procedure ,
below is my proc named test_call ,where it call test_out, an another procedure

1 ...............

DELIMITER $$

DROP PROCEDURE IF EXISTS `test_call` $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `test_call`()
BEGIN

/*
I am getting NULL when i run in and out as param , where as i am getting the result
when i am running this as in param ..
*/

# 1. Has in and out param
set @call2 = concat('call ' ,'test_out(',concat('21','0'),',',@b,')');
select @call2,@b;

# 2. Has in param only
#set @call2 = concat('call ' ,'test1(',concat('21','0'),')');
#select @call2;


PREPARE stmt2 FROM @call2;
EXECUTE stmt2;
DEALLOCATE PREPARE stmt2;


END $$

DELIMITER ;

----------------------------------------------------------------------
Proc 2
----------------------------------------------------------------------
DELIMITER $$

DROP PROCEDURE IF EXISTS `test_out` $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `test_out`(in numbersWith2Digit varchar(5),out sa text)
BEGIN

set @c = concat('123','456',concat('789'),numbersWith2Digit );
set sa = @c;
select sa;

END $$

DELIMITER ;
-------------------------------------------------------------------

Firstly, test_call is expecting @b before it is called. If you do not set this the result of the concat will be NULL.

Secondly, the IN OUT parameter must be a variable name and not a value. So in the first procedure test_call() you must define @b inside a string variable

Hi Ronan,

Thankyou very much for the reply... Now i understand where i did the mistake .Now code is working properly...