如何从表中获取jdbc空对象

Question

I have an sql column PROTOCOL of Number type .It is nullable and a constraint on the table PROTOCOL IN(1,2,3).I am able to set to null. How to get the value if its null? I can do rs.getInt() but I dont think it returns null?

if(protocol==0)
            {

               stmt.setNull(15, java.sql.Types.INTEGER);                

           }
            else{
            stmt.setInt(15, protocol);
            }

Answer 1

Use wasNull() method.

 Integer myValue = rs.getInt(15);
 if (rs.wasNull()) {
   myValue = null;
 }

Answer 2

I can do rs.getInt() but I dont think it returns null?

Use ResultSet.wasNull() after getInt() to check if the last column read was NULL.

Or, use ResultSet.getObject() instead of getInt() , which returns null if the column is NULL .