Join the left table with the right table and return all joined records of the left table. If no joined record is found, NULL will be returned.
1 2 | SELECT attr_expr_list FROM table_reference LEFT OUTER JOIN table_reference ON join_condition; |
LEFT OUTER JOIN: Returns all joined records of the left table. If no record is matched, NULL is returned.
The to-be-joined table must exist. Otherwise, an error is reported.
To join the courseId from the student_info table to the courseId from the course_info table for inner join and return the name of the students who have selected course, run the following statement. If no joined record is found, NULL will be returned.
1 2 | SELECT student_info.name, course_info.courseName FROM student_info LEFT OUTER JOIN course_info ON (student_info.courseId = course_info.courseId); |