I reviewed the IF NULL and COALESCE lessons but it creates only a duplicate column that fills in the null value. How do insert a value in an existing row indicated as null in an existing column? I tried INSERT INTO but I don't know how to insert in an existing row, only how to create a new row. I tried adding a WHERE clause but it gives me a syntax error.

Hi Helen! Thanks for reaching out. That's what an INSERT statement does - it inserts a new record. Otherwise, you can use an UPDATE statement. Please feel free to provide an example of a table/a state of a table, so that we can assist you more specifically. Hope this helps. Best, Martin