以非关系配置删除记录

Question

I am using MySQL and it is not a relational database (foreign keys constraints) so when I perform a delete on a record I want to check whether it is used in any other table, if so, don't delete.

I assume I would have to perform a database-wide search on all tables except it's own. I keep each records id uniform throughout the database.

Example:

Assets
id | date_created | type_id

History
asset_id | date_recorded | store_id

I found a script to find all the table that have the records id:

SELECT
    DISTINCT TABLE_NAME,
    TABLE_NAME.COLUMN_NAME
FROM
    INFORMATION_SCHEMA.COLUMNS
WHERE
    COLUMN_NAME IN ('desander_id')
    AND
    TABLE_SCHEMA='emp'

But I get an error on the TABLE_NAME.COLUMN_NAME part where it says COLUMN_NAME is unknown. Is there a way I can do this? Am I doing this the right way?

Answer 1

your from table is INFORMATION_SCHEMA.COLUMNS and you are selecting TABLE_NAME.COLUMN_NAME which not possible in MySQL. It should be like table_name.column_name . try this:

SELECT DISTINCT COLUMNS.TABLE_NAME,
                COLUMNS.COLUMN_NAME
FROM INFORMATION_SCHEMA.COLUMNS
WHERE COLUMN_NAME IN ('desander_id') AND
      TABLE_SCHEMA='emp';