飞路| MariaDb-无法执行条件块

Question

I want to add a not null column to a table with existing data. My toolset includes MariaDb and flyway. Here's what I am doing

IF NOT EXISTS(SELECT 1
                FROM INFORMATION_SCHEMA.COLUMNS
                WHERE table_name = 'MY_DATA_TABLE'
                AND table_schema = '${schemaName}'
                AND column_name = 'NewColumnName'
              ) THEN
        ALTER TABLE MY_DATA_TABLE ADD COLUMN 'NewColumnName' INT;
        SELECT ID INTO @val FROM MASTER_TABLE WHERE lower(Name) = 'XYZ';
        UPDATE MY_DATA_TABLE SET NewColumnName = @val;
        ALTER TABLE MY_DATA_TABLE MODIFY COLUMN 'NewColumnName' INT NOT NULL;
END IF;

Doing mvn flyway:migrate gives me this error

[ERROR] SQL State  : 42000
[ERROR] Error Code : 1064
[ERROR] Message    : You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near ''NewColumnName'
INT' at line 7

I even tried placing some running select statement inside, but the error remains the same. Please suggest some workaround. Please also recommend if there's another way to achieve the objective. Thanks!

Answer 1

I suspect the issue is with quoting the column name. Try executing the SQL interactively and see if you get the same error. Then try and get it working successfully. In a related question the answer was to try no quotes around column names or to escape them with back ticks.

Answer 2

Here's how I ended up to meet the desired.

DROP PROCEDURE IF EXISTS `proc_UpdateMyColumn`;
DELIMITER //

CREATE PROCEDURE `proc_UpdateMyColumn`
(
)
BEGIN
    DECLARE valueToSet INT;

    IF NOT EXISTS (SELECT 1
        FROM INFORMATION_SCHEMA.COLUMNS
        WHERE table_name = 'MY_DATA_TABLE'
        AND table_schema = '${schemaName}'
        AND column_name = 'NewColumnName'
    ) THEN
        ALTER TABLE MY_DATA_TABLE ADD COLUMN NewColumnName INT;
        SELECT ID INTO valueToSet FROM MASTER_TABLE WHERE lower(Name) = 'XYZ';
        UPDATE MY_DATA_TABLE SET NewColumnName = valueToSet;
        ALTER TABLE MY_DATA_TABLE MODIFY COLUMN NewColumnName INT NOT NULL;
    END IF;
END;
DELIMITER;

CALL `proc_UpdateMyColumn`();
DELIMITER;