Mysql stored procedure don't take table name as parameter

Question

I\'ve written a stored procedure. It\'s working fine except taking the table name as input parameter.

Let see my proc in MySQL:

DELIMITER $$
USE `d         


        

Answer 1

An SP cannot be optimized with a dynamic table name, so many DBs, MySQL included, don't allow table names to be specified dynamically.

One way around this is to use Dynamic SQL.

CREATE DEFINER=`root`@`localhost` PROCEDURE `test_proc`(IN serviceName VARCHAR(10),IN newsInfoTable VARCHAR(100))
BEGIN                  
    SET @sql = CONCAT('SELECT COUNT(*) FROM ',newsInfoTable,' WHERE newsServiceName=?;'); 
    PREPARE s1 from @sql;
    SET @paramA = serviceName;
    EXECUTE s1 USING @paramA;
END$$

Answer 2

You can use EXECUTE IMMEDIATE for a "less is more" solution (for me, less code = good)

CREATE PROCEDURE test_proc(IN serviceName VARCHAR(10), IN newsInfoTable VARCHAR(100))
BEGIN                  
    EXECUTE IMMEDIATE CONCAT('SELECT COUNT(*) FROM ',newsInfoTable,' WHERE newsServiceName=''', serviceName, ''''); 
END

Answer 3

that part of a query cannot be dynamic.

you may consider implementing as a string that is executed dynamically at runtime

Answer 4

Although may not be what you want, alternatively, can consider to use conditionally if and prepare the statement.

DELIMITER $$
CREATE PROCEDURE select_count(IN table_name VARCHAR(20))
BEGIN
  IF table_name = 'xxx' THEN
     SELECT * FROM xxx;
  ELSEIF table_name = 'yyy' THEN
     ...
  ENDIF
END$$