How can MySQL utilize the EXISTS and NOT EXISTS keywords?

9 months ago

Isabella Edwards

1 minute

In MySQL, you can use the EXISTS and NOT EXISTS keywords to determine if a subquery returns any rows.

Using the EXISTS keyword:

SELECT column1, column2
FROM table1
WHERE EXISTS (
    SELECT *
    FROM table2
    WHERE table1.column = table2.column
);

The query above will return rows in table1 that meet the condition of having rows that match columns in table2.

Utilize the NOT EXISTS keyword:

SELECT column1, column2
FROM table1
WHERE NOT EXISTS (
    SELECT *
    FROM table2
    WHERE table1.column = table2.column
);

The query above will return the rows in table1 that meet the condition of not having a match in table2 with the columns in table1.