Explain SQL statements on the left, right, and inside and outside

Internal JOIN: INNERJOIN or JOIN, which finds the data corresponding to the two tables. Outer Join: OUTERJOIN. The corresponding data is retrieved based on a table and divided into left Outer Join and right outer join. Left Outer Join: LEFTJOIN or LEFTOUTERJOIN. The corresponding data is retrieved based on a table. RIGHT outer join: RIGHTJOIN or RIGHT

Internal JOIN: inner join or JOIN to check the data corresponding to the two tables. Outer join: outer join, which identifies the corresponding data based on a table and is divided into left outer join and right outer join. Left outer join: left join or left outer join. The corresponding data is retrieved based on a table. Outer right join: right join or RIGHT

Student table
NO Name
1
2 B
3 c
4 d

Grade table
NO Grade
1 90
2 98
3 95
5 90

Inner join: The data corresponding to the search condition. No data is listed in no4.
Syntax: * from student inner join grade on student. no = grade. no
Result:
NO Name NO Grade
1 a 1 90
2 B 2 98
3 c 3 95

Left join: All data in the left table, corresponding data in the right table
Syntax: select * from student left join grade on student. no = grade. no
Result:
NO Name NO Grade
1 a 1 90
2 B 2 98
3 c 3 95
4 D

Right join: All data in the right table, corresponding data in the left table
Syntax: select * from student right join grade on student. no = grade. no
Result:
NO Name NO Grade
1 a 1 90
2 B 2 98
3 c 3 95
5 90

Full connection
Syntax: select * from student full join grade on student. no = grade. no
Result:
No name grade
1 a 90
2 B 98
3 c 95
4 d
1 a 90
2 B 98
3 c 95

Note: you cannot directly use full join in access. You must use union all to merge the left and right connections.