Detailed example of MySQL joint table update data

UPDATE T1, T2,
[INNER JOIN | LEFT JOIN] T1 ON T1.C1 = T2.C1
SET T1.C2 = T2.C2, 
 T2.C3 = expr
WHERE condition

CREATE DATABASE IF NOT EXISTS empdb;

USE empdb;
--create tables
CREATE TABLE merits (
 performance INT(11) NOT NULL,
 percentage FLOAT NOT NULL,
 PRIMARY KEY (performance)
);

CREATE TABLE employees (
 emp_id INT(11) NOT NULL AUTO_INCREMENT,
 emp_name VARCHAR(255) NOT NULL,
 performance INT(11) DEFAULT NULL,
 salary FLOAT DEFAULT NULL,
 PRIMARY KEY (emp_id),
 CONSTRAINT fk_performance FOREIGN KEY (performance)
  REFERENCES merits (performance)
);

-- insert data for merits table
INSERT INTO merits(performance,percentage)
VALUES(1,0),
  (2,0.01),
  (3,0.03),
  (4,0.05),
  (5,0.08);

-- insert data for employees table
INSERT INTO employees(emp_name,performance,salary)  
VALUES('Mary Doe', 1, 50000),
  ('Cindy Minsu', 3, 65000),
  ('Sue Greenspan', 4, 75000),
  ('Grace Dell', 5, 125000),
  ('Nancy Johnson', 3, 85000),
  ('John Doe', 2, 45000),
  ('Lily Bush', 3, 55000);

mysql> select * from employees; -- Update the previous data+--------+---------------+-------------+--------+
| emp_id | emp_name | performance | salary |
+--------+---------------+-------------+--------+
| 1 | Mary Doe | 1 | 50000 |
| 2 | Cindy Minsu | 3 | 65000 |
| 3 | Sue Greenspan | 4 | 75000 |
| 4 | Grace Dell | 5 | 125000 |
| 5 | Nancy Johnson | 3 | 85000 |
| 6 | John Doe | 2 | 45000 |
| 7 | Lily Bush | 3 | 55000 |
+--------+---------------+-------------+--------+
7 rows in set

mysql> UPDATE employees
  INNER JOIN
 merits ON employees.performance = merits.performance 
SET 
 salary = salary + salary * percentage; -- Execute connection update Query OK, 6 rows affected
Rows matched: 7 Changed: 6 Warnings: 0

mysql> select * from employees; -- Updated data+--------+---------------+-------------+--------+
| emp_id | emp_name | performance | salary |
+--------+---------------+-------------+--------+
| 1 | Mary Doe | 1 | 50000 |
| 2 | Cindy Minsu | 3 | 66950 |
| 3 | Sue Greenspan | 4 | 78750 |
| 4 | Grace Dell | 5 | 135000 |
| 5 | Nancy Johnson | 3 | 87550 |
| 6 | John Doe | 2 | 45450 |
| 7 | Lily Bush | 3 | 56650 |
+--------+---------------+-------------+--------+
7 rows in set

UPDATE employees
  INNER JOIN
 merits ON employees.performance = merits.performance 
SET 
 salary = salary + salary * percentage
WHERE employees.performance > 1;

INSERT INTO employees(emp_name,performance,salary)
VALUES('Jack William',NULL,43000),
  ('Ricky Bond', NULL, 52000);

mysql> SELECT * FROM employees;
+--------+---------------+-------------+--------+
| emp_id | emp_name | performance | salary |
+--------+---------------+-------------+--------+
| 1 | Mary Doe | 1 | 50000 |
| 2 | Cindy Minsu | 3 | 66950 |
| 3 | Sue Greenspan | 4 | 78750 |
| 4 | Grace Dell | 5 | 135000 |
| 5 | Nancy Johnson | 3 | 87550 |
| 6 | John Doe | 2 | 45450 |
| 7 | Lily Bush | 3 | 56650 |
| 8 | Jack William | NULL | 43000 |
| 9 | Ricky Bond | NULL | 52000 |
+--------+---------------+-------------+--------+
9 rows in set

UPDATE employees
  LEFT JOIN
 merits ON employees.performance = merits.performance 
SET 
 salary = salary + salary * 0.015
WHERE
 merits.percentage IS NULL;

mysql> UPDATE employees
  LEFT JOIN
 merits ON employees.performance = merits.performance 
SET 
 salary = salary + salary * 0.015
WHERE
 merits.percentage IS NULL;
Query OK, 2 rows affected
Rows matched: 2 Changed: 2 Warnings: 0

mysql> select * from employees;
+--------+---------------+-------------+--------+
| emp_id | emp_name | performance | salary |
+--------+---------------+-------------+--------+
| 1 | Mary Doe | 1 | 50000 |
| 2 | Cindy Minsu | 3 | 66950 |
| 3 | Sue Greenspan | 4 | 78750 |
| 4 | Grace Dell | 5 | 135000 |
| 5 | Nancy Johnson | 3 | 87550 |
| 6 | John Doe | 2 | 45450 |
| 7 | Lily Bush | 3 | 56650 |
| 8 | Jack William | NULL | 43645 |
| 9 | Ricky Bond | NULL | 52780 |
+--------+---------------+-------------+--------+
9 rows in set

# Single table join
update bbs_uhome_card_activate ca INNER JOIN bbs_uhome_card_rules cr on ca.card_brach=cr.card_bach set ca.create_user=cr.create_user;

# Multi-table join
UPDATE bbs_uhome_card_order co INNER JOIN bbs_uhome_card_order_record cor on co.order_no=cor.order_no JOIN bbs_uhome_card_activate ca on cor.card_no=ca.card_no set co.create_user=ca.create_user