Determining if MySQL table index exists before creating

Question

Our system\'s automated database migration process involves running .sql scripts containing new table definitions and their accompanying indexes.

I require the ability t

Answer 1

Not a new version but a more complete solution that includes a call to create 2 indexes.

USE MyDatabaseName;
DELIMITER $$
-- Create a temporary stored procedure for checking if Indexes exist before attempting to re-create them.
DROP PROCEDURE IF EXISTS `MyDatabaseName`.`spCreateIndex` $$
CREATE PROCEDURE `MyDatabaseName`.`spCreateIndex` (tableName VARCHAR(128), in indexName VARCHAR(128), in indexColumns VARCHAR(128))
BEGIN
  IF((SELECT COUNT(*) AS index_exists FROM information_schema.statistics WHERE TABLE_SCHEMA = DATABASE() AND table_name = tableName AND index_name = indexName)  = 0) THEN
    SET @sqlCommand = CONCAT('CREATE INDEX ' , indexName , ' ON ' , tableName, '(', indexColumns, ')');
    PREPARE _preparedStatement FROM @sqlCommand;
    EXECUTE _preparedStatement;
  END IF;
END $$
DELIMITER ;

-- Create the Indexes if they do not exist already.
CALL spCreateIndex('MyCustomers', 'idxCustNum', 'CustomerNumber');
CALL spCreateIndex('MyProducts', 'idxProductName', 'ProductName');

DELIMITER $$
-- Drop the temporary stored procedure.
DROP PROCEDURE IF EXISTS `MyDatabaseName`.`spCreateIndex` $$
DELIMITER ;