错误1452 MySQL和NodeJS。 数据库为什么不能正确引用我的表？

Question

So im getting Error 1452 from my Node console when inserting a new user account. Here is the error

{ Error: ER_NO_REFERENCED_ROW_2: Cannot add or update a child row: a foreign key constraint fails ( myeherlpertst2 . customers , CONSTRAINT customers_ibfk_1 FOREIGN KEY ( user_id ) REFERENCES users ( user_id ))

code: 'ER_NO_REFERENCED_ROW_2', errno: 1452, sqlMessage: 'Cannot add or update a child row: a foreign key constraint fails ( myeherlpertst2 . customers , CONSTRAINT customers_ibfk_1 FOREIGN KEY ( user_id ) REFERENCES users ( user_id ))', sqlState: '23000', index: 0,

Im very sure that the reason I am getting this error is because the customers table is trying to reference something that isnt there BUT I dont understand why its not referencing it. In my Node code below I insert the user table first which auto increments user_id and is not null. Do I have to end the transaction for the first insert and then start a new one before I can insert into the customers table?

    connection.beginTransaction(function(error){

    if(error){

    console.log('Error Caught');
    return res;
}

  if (error) {throw error;
    console.log('Error Caught');
    return;}
  connection.query('Insert into users( user_name, user_password, user_type) values (?,?,?)', [customer.body.userName, customer.body.password, userType=1], function (error, results, fields) {
    if (error) {
      console.log(error);
      return;
    }
      connection.query('Insert into customers(cust_first_name, cust_last_name, cust_email, cust_city, cust_address, cust_zip_code, cust_state, cust_phone_num, cust_role, cust_website, cust_business_name) values (?,?,?,?,?,?,?,?,?,?,?)', [customer.body.firstName, customer.body.lastName, customer.body.email, customer.body.city, customer.body.address, customer.body.zipCode, customer.body.state, customer.body.phoneNumber, customer.body.custRole=1, customer.body.website, customer.body.businessName], function (error, results, fields) {
      if (error) {
        console.log(error);
      }
      });
    res.end(JSON.stringify(results));
    });
    console.log('End Transaction')
  });

Answer 1

You need to set the user_id column correctly in the customers table. MySQL's LAST_INSERT_ID() function is the source of the value you need. Here's how to do that, in SQL.

Insert into users( user_name, user_password, user_type) values (?,?,?);

Insert into customers(user_id, cust_first_name, cust_last_name, cust_email, 
                      cust_city, cust_address, cust_zip_code, cust_state,
                      cust_phone_num, cust_role, cust_website, cust_business_name) 
              values (LAST_INSERT_ID(),?,?,?,?,?,?,?,?,?,?,?);

Notice that the insert into the customers table changes the value of LAST_INSERT_ID(), to the value of the autoincrementing ID in that table. So, if you need to reuse the value from the users table, do this, with three queries rather than two:

Insert into users( user_name, user_password, user_type) values (?,?,?);

SET @userid := LAST_INSERT_ID();

Insert into customers(user_id, cust_first_name, cust_last_name, cust_email, 
                      cust_city, cust_address, cust_zip_code, cust_state,
                      cust_phone_num, cust_role, cust_website, cust_business_name) 
              values (@userid,?,?,?,?,?,?,?,?,?,?,?);

I'll leave it to you to put the queries into your node program.

Answer 2

No need for another query : The result of an insert contain the last autoincrement insert id

This information is available with results.insertId.

So corrrection would be like :

connection.query(
      "Insert into users( user_name, user_password, user_type) values (?,?,?)",
      [customer.body.userName, customer.body.password, (userType = 1)],
      function(error, results, fields) {
        if (error) {
          console.log(error);
          return;
        }
        connection.query(
          "Insert into customers(user_id, cust_first_name, cust_last_name, cust_email, cust_city, cust_address, cust_zip_code, cust_state, cust_phone_num, cust_role, cust_website, cust_business_name) values (?,?,?,?,?,?,?,?,?,?,?,?)",
          [
            results.insertId,
            customer.body.firstName,
            customer.body.lastName,
            customer.body.email,
            customer.body.city,
            customer.body.address,
            customer.body.zipCode,
            customer.body.state,
            customer.body.phoneNumber,
            (customer.body.custRole = 1),
            customer.body.website,
            customer.body.businessName
          ],
          function(error, results, fields) {
            if (error) {
              console.log(error);
            }
          }
        );
        res.end(JSON.stringify(results));
      }
    );

btw: the parameter userType=1 must probably be an error