Dynamic table names in stored procedure function

Question

I\'ve written a stored procedure function to get a name from a table. The trouble is that I want the table name to be passed in as a parameter (there are several different t

Answer 1

If you want to buld a SQL statement using identifiers, then you need to use prepared statements; but prepared statements cannot be used in functions. So, you can create a stored procedure with OUT parameter -

CREATE PROCEDURE getName
 (IN tableName VARCHAR(50), IN myId INT(11), OUT myName VARCHAR(50))
BEGIN

  SET @GetName =
    CONCAT('SELECT name INTO @var1 FROM ', tableName, ' WHERE id=', myId);
  PREPARE stmt FROM @GetName;
  EXECUTE stmt;

  SET myName = @var1;
END

Using example -

SET @tableName = 'tbl';
SET @myId = 1005;
SET @name = NULL;
CALL getName(@tableName, @myId, @name);
SELECT @name;