JDBC returns wrong number of affected rows

Question

If we have a table with 10 rows and we execute this query twice we get the wrong number of affected rows the second time.

Statement st = open();

st.executeU         


        

Answer 1

The JDBC specification apparently dictates that drivers have executeUpdate() return the number of rows found by the UPDATE statement, not the number of rows actually affected.

To have MySQL Connector/J return the number of rows actually changed you can add the property useAffectedRows=true to your connection URL, although the documentation does warn that it is

not JDBC-compliant, will break most applications that rely on "found" rows vs. "affected rows" for DML statements