Topic describes

Select * from employees;

There is a department table with dept_EMp as follows:

Select last_name (last_name, first_name, dept_no) from all employees whose departments have been assigned.

Example 1 Enter: drop table if exists' dept_emp '; drop table if exists `employees` ; CREATE TABLE `dept_emp` ( `emp_no` int(11) NOT NULL, `dept_no` char(4) NOT NULL, `from_date` date NOT NULL, `to_date` date NOT NULL, PRIMARY KEY (`emp_no`,`dept_no`)); CREATE TABLE `employees` ( `emp_no` int(11) NOT NULL, `birth_date` date NOT NULL, `first_name` varchar(14) NOT NULL, `last_name` varchar(16) NOT NULL, `gender` char(1) NOT NULL, `hire_date` date NOT NULL, PRIMARY KEY (`emp_no`)); INSERT INTO dept_emp VALUES(10001,'d001','1986-06-26','9999-01-01'); INSERT INTO dept_emp VALUES(10002,'d002','1996-08-03','9999-01-01'); INSERT INTO employees VALUES(10001,'1953-09-02','Georgi','Facello','M','1986-06-26'); INSERT INTO employees VALUES(10002,'1964-06-02','Bezalel','Simmel','F','1985-11-21'); INSERT INTO employees VALUES(10003,'1959-12-03','Parto','Bamford','M','1986-08-28'); INSERT INTO employees VALUES(10004,'1954-05-01','Chirstian','Koblick','M','1986-12-01'); Copy the output: Facello | Georgi has | d001 Simmel | Bezalel | d002 Bamford | Parto | None Koblick | Chirstian | NoneCopy the code

Answer key

Select * from OUTER JOIN LEFT JOIN (OUTER JOIN LEFT JOIN);

Elapsed time: 15ms over 66.86% Code submitted with Sqlite Memory: 3344KB Over 38.32% code submitted with Sqlite

SELECT a.last_name, a.first_name, b.dept_no
FROM employees a LEFT JOIN dept_emp b
ON a.emp_no = b.emp_no;
Copy the code