/SQL/Drop column from table if exist on live server mysql

Drop column from table if exist on live server mysql

-- column_exists:

DROP FUNCTION IF EXISTS column_exists;

DELIMITER $$
CREATE FUNCTION column_exists(
  tname VARCHAR(64),
  cname VARCHAR(64)
)
  RETURNS BOOLEAN
  READS SQL DATA
  BEGIN
    RETURN 0 < (SELECT COUNT(*)
                FROM `INFORMATION_SCHEMA`.`COLUMNS`
                WHERE `TABLE_SCHEMA` = SCHEMA()
                      AND `TABLE_NAME` = tname
                      AND `COLUMN_NAME` = cname);
  END $$
DELIMITER ;

-- drop_column_if_exists:

DROP PROCEDURE IF EXISTS drop_column_if_exists;

DELIMITER $$
CREATE PROCEDURE drop_column_if_exists(
  tname VARCHAR(64),
  cname VARCHAR(64)
)
  BEGIN
    IF column_exists(tname, cname)
    THEN
      SET @drop_column_if_exists = CONCAT('ALTER TABLE `', tname, '` DROP COLUMN `', cname, '`');
      PREPARE drop_query FROM @drop_column_if_exists;
      EXECUTE drop_query;
    END IF;
  END $$
DELIMITER ;

Source: stackoverflow.com

Similar codes

0 vote155 views1 answer
How to find table lock and row lock in mysql
SQL
3 votes145 views1 answer
Sql replace character in string in all records
SQL
0 vote165 views2 answers
Uninstall postgresql mac
SQL
0 vote136 views1 answer
Mysql find missing values
SQL
3 votes149 views2 answers
Sqlite print all column names
SQL
1 vote150 views1 answer
Decalre temp table sql
SQL
7 votes157 views3 answers
Sql server reset auto increment
SQL
0 vote175 views1 answer
Python mysql executemany
SQL
1 vote144 views1 answer
Oracle get current schema
SQL
4 votes146 views1 answer
Mac install mysql
SQL