MySQL “NOT IN” query

MySQLsql

I wanted to run a simple query to throw up all the rows of Table1 where a principal column value is not present in a column in another table (Table2).

I tried using:

SELECT * FROM Table1 WHERE Table1.principal NOT IN Table2.principal

This is instead throwing a syntax error. Google search led me to forums where people were saying that MySQL does not support NOT IN and something extremely complex needs to be used. Is this true? Or am I making a horrendous mistake?

Best Answer

To use IN, you must have a set, use this syntax instead:

SELECT * FROM Table1 WHERE Table1.principal NOT IN (SELECT principal FROM table2)