java - 你好，java/database near where syntax error

Question

每次我尝试更新它时都会说 - 在“WHERE”附近:语法错误。我已经成功地能够更新程序中类的其他部分，但这不知何故给了我这个错误。

我认为问题出在这里:

public void update_account(){
           try { //start or try
               //1)create a connection variable
               Connection con;
               //2)create an instance of the database class
               Database db=new Database();
               //3)pass the connection from DB to con
               con=db.open_connection();
               //4)create a statement variable to prepare the SQL
               Statement statement=con.createStatement();
               //5)create a query to insert the records
               String query="UPDATE tblUsers SET fullname='" + txtFullname.getText()+"',"
                    + "username='" + txtUsername.getText()+"',"
                    + "password='" + txtPassword.getText()+"',"
                    + "WHERE userID="+ accid +"";
               //6) execute the SQL code
               if(statement.executeUpdate(query)==1) { //query was successful
                   JOptionPane.showMessageDialog(null, "Reference successfully updated!");
                   //clear the inputs
                   new MainInterface(user);
                   frmAccountSett.dispose();

               }
           }//end of try
           catch (Exception e){//start of catch
               //display the error
               JOptionPane.showMessageDialog(null,e.getMessage());
           }//end of catch
        }//end of save_recipe()

为了以防万一，下面是完整的代码；

public void update_account(){
           try { //start or try
               //1)create a connection variable
               Connection con;
               //2)create an instance of the database class
               Database db=new Database();
               //3)pass the connection from DB to con
               con=db.open_connection();
               //4)create a statement variable to prepare the SQL
               Statement statement=con.createStatement();
               //5)create a query to insert the records
               String query="UPDATE tblUsers SET fullname='" + txtFullname.getText()+"',"
                    + "username='" + txtUsername.getText()+"',"
                    + "password='" + txtPassword.getText()+"',"
                    + "WHERE userID="+ accid +"";
               //6) execute the SQL code
               if(statement.executeUpdate(query)==1) { //query was successful
                   JOptionPane.showMessageDialog(null, "Reference successfully updated!");
                   //clear the inputs
                   new MainInterface(user);
                   frmAccountSett.dispose();

               }
           }//end of try
           catch (Exception e){//start of catch
               //display the error
               JOptionPane.showMessageDialog(null,e.getMessage());
           }//end of catch
        }//end of save_recipe()

Answer 1

对于sql表更新，语法如下:

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

请注意，where 关键字前没有逗号。在您的代码中，您在导致错误的 WHERE 关键字之前添加了逗号