August 13th, 2010 |
| A | B |
| 1 | a |
| 2 | b |
| 3 | c |
| C | D |
| 2 | c |
| 3 | b |
| 4 | a |
select T1.*,T2.* from T1 left join T2 on T1.A=T2.C
| A | B | C | D |
| 1 | a | NULL | NULL |
| 2 | b | 2 | c |
| 3 | c | 3 | b |
簡單講，就是以左邊為準。
July 30th, 2010 |
| A | B |
| 1 | a |
| 2 | b |
| 3 | c |
| C | D |
| 2 | c |
| 3 | b |
| 4 | a |
select T1.*,T2.* from T1 left join T2 on T1.A=T2.C
| A | B | C | D |
| 1 | a | NULL | NULL |
| 2 | b | 2 | c |
| 3 | c | 3 | b |
簡單講，就是以左邊為準。
