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

Since Text and Blobs need a size, I added it to the stored procedure.

DROP PROCEDURE IF EXISTS createIndex;

DELIMITER $$
-- Create a temporary stored procedure for checking if Indexes exist before attempting to re-create them. => can be called
$$
CREATE PROCEDURE `createIndex`(
    IN `tableName` VARCHAR(128),
    IN `indexName` VARCHAR(128),
    IN `indexColumns` VARCHAR(128),
    IN `indexSize` 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
        IF(indexSize > 0) THEN
            SET @sqlCommand = CONCAT('CREATE INDEX ' , indexName , ' ON ' , tableName, '(', indexColumns, '(' , indexSize, '))');
        ELSE
            SET @sqlCommand = CONCAT('CREATE INDEX ' , indexName , ' ON ' , tableName, '(', indexColumns, ')');
        END IF;
    PREPARE _preparedStatement FROM @sqlCommand;
    EXECUTE _preparedStatement;
  END IF;
END $$
DELIMITER ;