java - 使用Prepared插入MySQL数据库

Question

我正在使用PreparedStatement至insert进入mysql，当我 checkin mysql console 时，我没有收到任何错误，但数据尚未插入。它说Empty set :

  public void insertGeometryValues(String gisuniqkey,String objkey,String objtype,String geometry)
{
    PreparedStatement statement=null;
    String sql="Insert into ZMAPERP_GIS_DB (GISUNIQKEY, GEOMETRY,OBJTYPE,OBJKEY) values(?,?,?,?);";
    try {
        conn.setAutoCommit(false);
        statement=(PreparedStatement) conn.prepareStatement(sql);
        statement.setString(1, gisuniqkey);
        statement.setString(2,geometry);
        statement.setString(3,objtype);
        statement.setString(4,objkey);
        conn.commit();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

我还尝试使用 Statement像这样并得到这个ERROR

 try {
        if(conn==null)
        {
            System.out.println("The connection was not initialized.");
            return false;
        }
        Statement st=(Statement) conn.createStatement();
        String sql="Insert into ZMAPERP_GIS_DB (GISUNIQKEY, GEOMETRY,OBJTYPE,OBJKEY) values('"+gisuniqkey+"','"+geometry+"','"+objtype+"',"+objkey+"');";
        System.out.println(sql);
        rc=st.executeUpdate(sql);
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

Answer 1

您对PreparedStatement的使用从未真正执行该语句。将代码更改为:

public void insertGeometryValues(String gisuniqkey,String objkey,String objtype,String geometry) {
    String sql="Insert into ZMAPERP_GIS_DB (GISUNIQKEY, GEOMETRY,OBJTYPE,OBJKEY) values(?,?,?,?);";
    conn.setAutoCommit(false);
    try (PreparedStatement statement = conn.prepareStatement(sql)) {
        statement.setString(1, gisuniqkey);
        statement.setString(2,geometry);
        statement.setString(3,objtype);
        statement.setString(4,objkey);
        statement.executeUpdate(); // <---- This is what is missing!
        conn.commit();
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
}

我还添加了 try-with-resources，以便该语句实际上正确关闭。