예제 테이블
table_a
| id |
upper
|
| 210 |
A
|
| 211 |
B
|
| 212 |
C
|
| 213 |
D
|
| 214 |
E
|
| 215 |
F
|
table_b
| id |
lower
|
| 210 |
a
|
| 212 |
c
|
| 212 |
c
|
| 215 |
f
|
| 216 |
g
|
| 217 |
h
|
INNER JOIN
SELECT table_a.id, table_a.upper, table_b.lower FROM table_a INNER JOIN table_b ON table_a.id=table_b.id
실행결과
table_a
| id |
upper
|
| 210 |
A
|
| 211 |
B
|
| 212 |
C
|
| 213 |
D
|
| 214 |
E
|
| 215 |
F
|
table_b
| id |
lower
|
| 210 |
a
|
| 212 |
c
|
| 212 |
c
|
| 215 |
f
|
| 216 |
g
|
| 217 |
h
|
LEFT JOIN
| table_a.id |
table_b.id
|
| 210
|
| 211 |
|
| 212
|
| 213 |
|
| 214 |
|
| 215
|
| |
216
|
| |
217
|
result
| id |
upper |
lower
|
| 210 |
A |
a
|
| 212 |
C |
c
|
| 212 |
C |
c
|
| 215 |
F |
f
|
LEFT OUTER JOIN
SELECT table_a.id, table_a.upper, table_b.lower FROM table_a LEFT OUTER JOIN table_b ON table_a.id=table_b.id
실행결과
table_a
| id |
upper
|
| 210 |
A
|
| 211 |
B
|
| 212 |
C
|
| 213 |
D
|
| 214 |
E
|
| 215 |
F
|
table_b
| id |
lower
|
| 210 |
a
|
| 212 |
c
|
| 212 |
c
|
| 215 |
f
|
| 216 |
g
|
| 217 |
h
|
LEFT JOIN
| table_a.id |
table_b.id
|
| 210
|
| 211 |
|
| 212
|
| 213 |
|
| 214 |
|
| 215
|
| |
216
|
| |
217
|
result
| id |
upper |
lower
|
| 210 |
A |
a
|
| 211 |
B |
(null)
|
| 212 |
C |
c
|
| 212 |
C |
c
|
| 213 |
D |
(null)
|
| 214 |
E |
(null)
|
| 215 |
F |
f
|
