order by
详情
根据order by指定的列，对结果排序。
用法
order by col [asc | desc] [nulls first | nulls last] 其中：
-
[asc | desc] 指定按升序或降序对数据进行排序。若不指定，则默认为升序。
-
[nulls first | nulls last] 指定空值放在排序查询结果的最前面或最后面。
- 在查询分布式表时，不支持对 col 使用序列函数和自定义函数。
注： 指定 nulls first/last 时，必须要指定 asc/desc。
例子
sym = `C`MS`MS`MS`IBM`IBM`C`C`C$SYMBOL
price= 49.6 29.46 29.52 30.02 174.97 175.23 50.76 50.32 51.29
qty = 2200 1900 2100 3200 6800 5400 1300 2500 8800
timestamp = [09:34:07,09:36:42,09:36:51,09:36:59,09:32:47,09:35:26,09:34:16,09:34:26,09:38:12]
t1 = table(timestamp, sym, qty, price);
t1;| timestamp | sym | qty | price |
|---|---|---|---|
| 09:34:07 | C | 2200 | 49.6 |
| 09:36:42 | MS | 1900 | 29.46 |
| 09:36:51 | MS | 2100 | 29.52 |
| 09:36:59 | MS | 3200 | 30.02 |
| 09:32:47 | IBM | 6800 | 174.97 |
| 09:35:26 | IBM | 5400 | 175.23 |
| 09:34:16 | C | 1300 | 50.76 |
| 09:34:26 | C | 2500 | 50.32 |
| 09:38:12 | C | 8800 | 51.29 |
select * from t1 order by sym, timestamp;| timestamp | sym | qty | price |
|---|---|---|---|
| 09:34:07 | C | 2200 | 49.6 |
| 09:34:16 | C | 1300 | 50.76 |
| 09:34:26 | C | 2500 | 50.32 |
| 09:38:12 | C | 8800 | 51.29 |
| 09:32:47 | IBM | 6800 | 174.97 |
| 09:35:26 | IBM | 5400 | 175.23 |
| 09:36:42 | MS | 1900 | 29.46 |
| 09:36:51 | MS | 2100 | 29.52 |
| 09:36:59 | MS | 3200 | 30.02 |
可使用"desc"关键字进行降序排序。
select * from t1 where sym in `C`IBM order by sym, timestamp desc;| timestamp | sym | qty | price |
|---|---|---|---|
| 09:38:12 | C | 8800 | 51.29 |
| 09:34:26 | C | 2500 | 50.32 |
| 09:34:16 | C | 1300 | 50.76 |
| 09:34:07 | C | 2200 | 49.6 |
| 09:35:26 | IBM | 5400 | 175.23 |
| 09:32:47 | IBM | 6800 | 174.97 |
t = table(5 3 NULL NULL 1 6 8 as id, 1 2 3 4 5 6 7 as val)
select * from t order by id asc nulls last| id | val |
|---|---|
| 1 | 5 |
| 3 | 2 |
| 5 | 1 |
| 6 | 6 |
| 8 | 7 |
| 3 | |
| 4 |
t = table(5 3 NULL NULL 1 6 8 as id, 1 2 3 4 5 6 7 as val)
select * from t order by id asc nulls first| id | val |
|---|---|
| 3 | |
| 4 | |
| 1 | 5 |
| 3 | 2 |
| 5 | 1 |
| 6 | 6 |
| 8 | 7 |