如何区分MySQL中INT列中的0和null

我真不敢相信,事情就是这样。
更改实体中对象类型的基元类型(例如:int->Integer)

若要区分0和NULL,应使用ResultSet.wasNull()方法,如下所示:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Main {
public static void main(String[] args) throws Exception {    
Connection conn = getConnection();
Statement st = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,
    ResultSet.CONCUR_UPDATABLE);

st.executeUpdate("create table survey (id int,name varchar(30));");
st.executeUpdate("insert into survey (id,name ) values (1,'nameValue')");
st.executeUpdate("insert into survey (id,name ) values (2,null)");
st.executeUpdate("insert into survey (id,name ) values (3,'Tom')");
st = conn.createStatement();
ResultSet rs = st.executeQuery("SELECT * FROM survey");

while (rs.next()) {
  String name = rs.getString(2);
  if (rs.wasNull()) {
    System.out.println("was NULL");
  } else {
    System.out.println("not NULL");
  }
}

rs.close();
st.close();
conn.close();
}

Integer id;
Object o = rs.getObject("ID_COLUMN");
if(o!=null){
   id = (Integer) o;
} else {
   id = null;
}