使用數字對 MySQL 字串進行排序?


要對帶數字的 MySQL 字串排序,以下是語法,其中我們使用了 ORDER BY、SUBSTR() 和 CAST() −

SELECT *FROM yourTableName ORDER BY
SUBSTR(yourColumnName FROM 1 FOR 2),
CAST(SUBSTR(yourColumnName FROM 2) AS UNSIGNED);

要理解上述語法,讓我們建立一個表。建立表查詢如下 −

mysql> create table OrderByStringWithNumbers
   -> (
   -> Id int NOT NULL AUTO_INCREMENT,
   -> Words varchar(10),
   -> PRIMARY KEY(Id)
   -> );
Query OK, 0 rows affected (0.86 sec)

使用插入命令向表中插入一些記錄。查詢如下 −

mysql> insert into OrderByStringWithNumbers(Words) values('A10');
Query OK, 1 row affected (0.19 sec)

mysql> insert into OrderByStringWithNumbers(Words) values('A30');
Query OK, 1 row affected (0.19 sec)

mysql> insert into OrderByStringWithNumbers(Words) values('A12');
Query OK, 1 row affected (0.13 sec)

mysql> insert into OrderByStringWithNumbers(Words) values('A11');
Query OK, 1 row affected (0.17 sec)

mysql> insert into OrderByStringWithNumbers(Words) values('A28');
Query OK, 1 row affected (0.13 sec)

mysql> insert into OrderByStringWithNumbers(Words) values('A21');
Query OK, 1 row affected (0.20 sec)

使用 select 語句從表中顯示所有記錄 −

mysql> select *from OrderByStringWithNumbers;

以下是輸出 −

+----+-------+
| Id | Words |
+----+-------+
| 1  | A10   |
| 2  | A30   |
| 3  | A12   |
| 4  | A11   |
| 5  | A28   |
| 6  | A21   |
+----+-------+
6 rows in set (0.00 sec)

以下是按帶數字的字串排序的查詢 −

mysql> select *from OrderByStringWithNumbers order by
   -> substr(Words from 1 for 2),
   -> cast(substr(Words from 2) AS UNSIGNED);

以下是輸出 −

+----+-------+
| Id | Words |
+----+-------+
| 1  | A10   |
| 4  | A11   |
| 3  | A12   |
| 6  | A21   |
| 5  | A28   |
| 2  | A30   |
+----+-------+
6 rows in set (0.00 sec)

更新於:30-6-2020

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