Delete row if table exists

Question

I want to delete a row from a table if that table exists.

Below is the delete statement

DELETE 
FROM UM_CLAIM_BEHAVIOR 
WHERE UM_TENANT_ID = ?

Can I extend this query to check the existence of the table or is there any other alternative to check existence of table before executing delete query?

According to comments it is not possible to give a platform-independent solution for this.

Answer 1

In SQL Server you could do something like this

IF EXISTS (
        SELECT 1
        FROM sys.objects AS o
        INNER JOIN sys.schemas AS s
            ON s.schema_id = o.schema_id
        WHERE CONCAT (s.NAME, '.', o.NAME) = 'dbo.UM_CLAIM_BEHAVIOR'
            AND o.type_desc = 'USER_TABLE'
        )
BEGIN
    DELETE T
    FROM UM_CLAIM_BEHAVIOR AS T
    WHERE UM_TENANT_ID = ?
END

Answer 2

You can do a platform-independant method, you just have to make a round trip to the server.

SELECT 'DELETE FROM ' || t.table || ' WHERE WHATEVER;'
FROM information_schema.tables
WHERE table_name = 'mytable';

Now you execute the whatever that returns. If the table exists, it'll return the query to delete the row. If not, it'll return NULL.