I want to add a column to a table, but I don't want it to fail if it has already been added to the table. How can I achieve this?
# Add column fails if it already exists
ALTER TABLE `TableName` ADD `ColumnName` int(1) NOT NULL default '0';
Use the following in a stored procedure:
IF NOT EXISTS( SELECT NULL
FROM INFORMATION_SCHEMA.COLUMNS
WHERE table_name = 'tablename'
AND table_schema = 'db_name'
AND column_name = 'columnname') THEN
ALTER TABLE `TableName` ADD `ColumnName` int(1) NOT NULL default '0';
END IF;
Reference: