oracle where 子句与 case when

Question

我试图避免使用动态 sql。我需要检查参数中的值，并根据它应用正确的子句。

例如：

select * from table
WHERE 1 =
CASE
    WHEN channel = 1 AND REGEXP_LIKE(LOGIN, '[[:digit:]]') THEN 1--only numbers
    WHEN channel = 2 AND LOGIN LIKE 'MI|%' THEN 1
    WHEN channel = 3 AND LOGIN NOT LIKE 'MI|%' AND NOT REGEXP_LIKE(LOGIN, '^\d+(\.\d+)?$', '') THEN 1 --except what is being filtered on case 1 and 2
    ELSE 0
END    

来自 LOGIN 列的样本数据：

VIC.A67923
2013836
257551
GAB.A53272
MI|1234
MI|5345

单独运行过滤器，它们工作正常，但测试为参数分配正确的值，它返回错误的数据。

例如当传递 1 时，它应该只返回那些有数字的，但它也返回有文本的数据。

Answer 1

您没有锚定并重复您的数字检查。将其锚定到字符串的开头和结尾。你所有的情况都返回 1，所以它最终什么都不做

SELECT *
  FROM tablea
 WHERE 1 = CASE WHEN channel = 1 AND REGEXP_LIKE (login, '^[[:digit:]]*$')
               THEN 1                                                                                      --only numbers
               WHEN channel = 2 AND login LIKE 'MI|%'
               THEN 1
               WHEN channel = 3 AND login NOT LIKE 'MI|%' AND NOT REGEXP_LIKE (login, '^\d+(\.\d+)?$', '')
               THEN 1                                                     --except what is being filtered on case 1 and 2
               ELSE 1
           END

Answer 2

改变你的情况

CASE
    WHEN channel = 1 AND REGEXP_LIKE(LOGIN, '[[:digit:]]') 
        THEN 1--only numbers
    WHEN channel = 2 AND LOGIN LIKE 'MI|%' 
        THEN 2
    WHEN channel = 3 AND LOGIN NOT LIKE 'MI|%' AND NOT REGEXP_LIKE(LOGIN, '^\d+(\.\d+)?$', '') 
        THEN 3 --except what is being filtered on case 1 and 2
    ELSE 4
END

或者，如果channel 是一个输入参数：

WHERE channel =
    CASE
        WHEN REGEXP_LIKE(LOGIN, '[[:digit:]]') 
            THEN 1--only numbers
        WHEN LOGIN LIKE 'MI|%' 
            THEN 2
        WHEN LOGIN NOT LIKE 'MI|%' AND NOT REGEXP_LIKE(LOGIN, '^\d+(\.\d+)?$', '') 
            THEN 3 --except what is being filtered on case 1 and 2
        ELSE 4
    END