java -通用sql排序语句

• 升序(asc)
• 降序(desc)

//年龄进行升序排序 （默认升序排列）
select *from t_user order by age;
select *from t_user order by age asc;

+----+-----------+-----+--------+---------+
| id | name      | age | gender | content |
+----+-----------+-----+--------+---------+
|  4 | Lili      |  16 |      0 | NULL    |
|  2 | HanMeimei |  17 |      0 | NULL    |
|  3 | Lucy      |  17 |      0 | NULL    |
| 10 | Ka_te     |  17 |      1 | NULL    |
|  1 | LiLei     |  18 |      1 | NULL    |
|  9 | ZhangWei  |  18 |      1 | NULL    |
|  8 | Lisa      |  19 |      0 | ceshi   |
|  6 | ZhangWei  |  25 |      1 | NULL    |
|  5 | WeiHua    |  32 |      0 | NULL    |
|  7 | Ann       |  36 |      0 | NULL    |
+----+-----------+-----+--------+---------+

//降序
select *from t_user order by age desc;

+----+-----------+-----+--------+---------+
| id | name      | age | gender | content |
+----+-----------+-----+--------+---------+
|  7 | Ann       |  36 |      0 | NULL    |
|  5 | WeiHua    |  32 |      0 | NULL    |
|  6 | ZhangWei  |  25 |      1 | NULL    |
|  8 | Lisa      |  19 |      0 | ceshi   |
|  1 | LiLei     |  18 |      1 | NULL    |
|  9 | ZhangWei  |  18 |      1 | NULL    |
|  2 | HanMeimei |  17 |      0 | NULL    |
|  3 | Lucy      |  17 |      0 | NULL    |
| 10 | Ka_te     |  17 |      1 | NULL    |
|  4 | Lili      |  16 |      0 | NULL    |
+----+-----------+-----+--------+---------+

//当年龄相同时 再按照name的升序排序
1.多个字段排序 靠前的字段优先级越高
2.只有前面字段age相等的时候 才会按照后面name字段排序
select *from t_user order by age desc , name asc;

+----+-----------+-----+--------+---------+
| id | name      | age | gender | content |
+----+-----------+-----+--------+---------+
|  7 | Ann       |  36 |      0 | NULL    |
|  5 | WeiHua    |  32 |      0 | NULL    |
|  6 | ZhangWei  |  25 |      1 | NULL    |
|  8 | Lisa      |  19 |      0 | ceshi   |
|  1 | LiLei     |  18 |      1 | NULL    |
|  9 | ZhangWei  |  18 |      1 | NULL    |
|  2 | HanMeimei |  17 |      0 | NULL    |
| 10 | Ka_te     |  17 |      1 | NULL    |
|  3 | Lucy      |  17 |      0 | NULL    |
|  4 | Lili      |  16 |      0 | NULL    |
+----+-----------+-----+--------+---------+

//按照第三个字段age进行排序（不建议这么写）
select *from t_user order by 3;

+----+-----------+-----+--------+---------+
| id | name      | age | gender | content |
+----+-----------+-----+--------+---------+
|  4 | Lili      |  16 |      0 | NULL    |
|  2 | HanMeimei |  17 |      0 | NULL    |
|  3 | Lucy      |  17 |      0 | NULL    |
| 10 | Ka_te     |  17 |      1 | NULL    |
|  1 | LiLei     |  18 |      1 | NULL    |
|  9 | ZhangWei  |  18 |      1 | NULL    |
|  8 | Lisa      |  19 |      0 | ceshi   |
|  6 | ZhangWei  |  25 |      1 | NULL    |
|  5 | WeiHua    |  32 |      0 | NULL    |
|  7 | Ann       |  36 |      0 | NULL    |
+----+-----------+-----+--------+---------+