/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 vote175 views1 answer
Sql add calculated column
SQL
0 vote260 views1 answer
ORA-00942
SQL
2 votes187 views3 answers
Sql delete duplicate
SQL
2 votes164 views1 answer
Add 2 hours to current time in MySQL
SQL
0 vote212 views1 answer
Alter column to not null with default value sql server
SQL
0 vote185 views2 answers
Timing sql queries
SQL
7 votes210 views5 answers
Sql remove spaces
SQL
7 votes171 views1 answer
Minecraft forge server host
SQL
6 votes167 views4 answers
Eloquent to sql with bindings
SQL
1 vote166 views2 answers
Into sql
SQL