如何获取SQL中特定记录列的最小值？

Question

SQL / MySQL

从测试中选择*；

fare_str = varchar（100）数据类型。

+-----------------+-------------+-------------+
| fare_str        | operator_id | bus_type_id |
+-----------------+-------------+-------------+
| 550,600,555     |           7 |          62 |
| 650,660         |           2 |          77 |
| 449,449,449,449 |           4 |          77 |
| 333             |          21 |          75 |
| 650             |           7 |          50 |
| 500             |           2 |          97 |
+-----------------+-------------+-------------+

所需的输出：在这里，我如何通过sql查询获取特定原始值和列fare_str的最小值；

+-----------------+-------------+-------------+
| fare_str        | operator_id | bus_type_id |
+-----------------+-------------+-------------+
| 550             |           7 |          62 |
| 650             |           2 |          77 |
| 449             |           4 |          77 |
| 333             |          21 |          75 |
| 650             |           7 |          50 |
| 500             |           2 |          97 |
+-----------------+-------------+-------------+

Answer 1

尝试这个

    SELECT MIN(SUBSTRING_INDEX(SUBSTRING_INDEX(t.fare_str, ',', n.n), ',', -1)) value,operator_id, bus_type_id  
    FROM Table1 t CROSS JOIN 
      (
       SELECT a.N + b.N * 10 + 1 n
       FROM 
          (SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) a
         ,(SELECT 0 AS N UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) b
       ORDER BY n 
       ) n
    WHERE n.n <= 1 + (LENGTH(t.fare_str) - LENGTH(REPLACE(t.fare_str, ',', '')))
    Group By operator_id, bus_type_id  

Answer 2

如果最小值是第一个，则使用Substring_Index。 查询相同

SELECT Substring_Index(fare_str,',' ,1), operator_id, bus_type_id  from test

如果介于两者之间的是最小值，则请参考以下线程：

MySQL中的“反向GROUP_CONCAT”？