在MySQL / MariaDB中将CHAR主键转换为INT

Question

我有一个使用CHAR作为客户主键的表。 我试图将此表加载到架构中，以便主键应为INT 。

DROP TABLE IF EXISTS `customers`;
CREATE TABLE `customers` (
  `customer_id` char(5) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO `customers` VALUES ('99944'),('99946'),('99976'),('A0014'),('A0049'),('A0124'),('C01AH'),('C01AQ'),('C01AW'),('C01AX'),('C01AY'),('C01AZ');

小提琴

我已经尝试select cast(customer_id AS UNSIGNED) FROM customers; 但对于非整数行，仅返回0。 如何将非整数行转换为一致的INT结果？

理想的结果如下所示：对于仅是整数的客户ID，请不要理会它们。 对于包含任何字母的客户ID，请用唯一的数字标识符替换ID中的所有内容。

预期结果：

SELECT * FROM Customers;

`customer_id`
-------
99944
99946
99976
13871911
13871912
13871913
13872128
13872229
13872293
13872505
13872512
13872561

Answer 1

在Maria DB> = 10.0.5的情况下，以下是一种以可预测的方式将字符串主键转换为整数主键的解决方案：

SELECT 
    customer_id old_id,
    CAST(
        REGEXP_REPLACE(customer_id, '([^0-9])', ORD('$1')) 
        AS UNSIGNED
    ) new_id
FROM customers;

REGEXP_REPLACE()捕获非数字字符（在字符串中的任何位置），而ORD()将每个字符转换为其有序（数字）表示。

DB Fiddle上的演示 ：

old_id |   new_id
:----- | -------:
99944  |    99944
9Z946  |   936946
A9CZ6  | 36936366
A0C14  |  3603614
0ABC0  |  3636360

Answer 2

GMB确实给了我另一个想法。
使用HEX()和CONV(.., 16, 10) 16，10 CONV(.., 16, 10)从十六进制转换为十进制

询问

SELECT
   customers.customer_id
 , CASE 
    WHEN (customers.customer_id >> 0) > 0
    THEN customers.customer_id >> 0
    ELSE
     CONV(HEX(customers.customer_id), 16, 10)
    END
   AS customer_id_int
FROM 
 customers;

结果

| customer_id | customer_id_int |
| ----------- | --------------- |
| 99944       | 99944           |
| 99946       | 99946           |
| 99976       | 99976           |
| A0014       | 279981338932    |
| A0049       | 279981339705    |
| A0124       | 279981404724    |
| C01AH       | 288571343176    |
| C01AQ       | 288571343185    |
| C01AW       | 288571343191    |
| C01AX       | 288571343192    |
| C01AY       | 288571343193    |
| C01AZ       | 288571343194    |

ps可能会生成一个需要使用BIGINT数据类型的int。
观看演示

更新

另一种生成较小int的方法（ UNSIGNED INT ），该方法使用“ SQL数字生成器”， SUBSTRING() ， ORD()和GROUP_CONCAT() 。

询问

    SELECT 
       customers.customer_id
     CASE 
       WHEN customers.customer_id >> 1 > 0
       THEN customers.customer_id 
       ELSE
         GROUP_CONCAT(
           CASE
             WHEN SUBSTRING(customers.customer_id, number_generator.number, 1) NOT BETWEEN 'A' AND 'Z'
             THEN SUBSTRING(customers.customer_id, number_generator.number, 1) >> 1
             ELSE ORD(SUBSTRING(customers.customer_id, number_generator.number, 1))
           END
           ORDER BY 
             number_generator.number ASC
           SEPARATOR ''
         )                            
     END                            
   ) AS customer_id_int                  
    FROM (
      SELECT 
       record_1.number
      FROM (
        SELECT 1 AS number UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5
      ) AS record_1   
    ) AS number_generator
    CROSS JOIN
     customers
    GROUP BY 
     customers.customer_id
    ORDER BY 
     customers.customer_id ASC

结果

| customer_id | customer_id_int |
| ----------- | --------------- |
| 99944       | 99944           |
| 99946       | 99946           |
| 99976       | 99976           |
| A0014       | 650002          |
| A0049       | 650024          |
| A0124       | 650012          |
| C01AH       | 67006572        |
| C01AQ       | 67006581        |
| C01AW       | 67006587        |
| C01AX       | 67006588        |
| C01AY       | 67006589        |
| C01AZ       | 67006590        |

观看演示

Answer 3

使用MySQL 8.0 REGEXP_REPLACE ：

select cast(REGEXP_REPLACE(customer_id,'[^0-9]','') AS UNSIGNED) FROM customers;

db <> fiddle演示