Error #1241 - Operand should contain 1 column(s)

Question

I am trying this QUERY, and return this weird error. What does it mean?

Here is my query:

SELECT * FROM newRowP a WHERE a.rowId IN 
(SELECT * FROM newCellP b WHERE b.cellId IN 
(SELECT * FROM newproviderP c WHERE c.pId IN ('3000344','245')))

Answer 1

Your subqueries, which SELECT *, are returning more than one column; whereas IN () requires exactly one column to be returned.