案例语句语法MySQL

Question

我有一个运行良好的MySQL存储过程

BEGIN 
SELECT ID, SID, SerialNumber, SerialType
FROM orders
WHERE paymentStatus =  'Completed'
AND paymentSuccess =  '1'
AND VerificationStatus IS NULL 
OR VerificationStatus NOT IN ('Found', 'NotFound', 'NotVerified');
END

但是我需要更改它以根据传递给SerialType的值来不同地返回。 我认为，使用case语句可能是实现此目的的最佳方法，但是努力寻找正确的语法，下面的示例显示了逻辑以及到目前为止我已经尝试过的内容。

BEGIN 
SELECT ID, SID, SerialNumber, SerialType
FROM orders
CASE
    WHEN SerialType IN ('Var1','Var2') THEN
        WHERE paymentStatus =  'Completed' AND paymentSuccess =  '1';
    WHEN SerialType IN ('Var3','Var4') THEN
        WHERE paymentStatus =  'Completed' AND paymentSuccess =  '1' AND VerificationStatus IS NULL OR VerificationStatus NOT IN ('Found', 'NotFound', 'NotVerified');
END CASE
END

Answer 1

看来您正在尝试执行以下操作：

SELECT ID, SID, SerialNumber, SerialType
FROM orders
WHERE paymentStatus =  'Completed' AND paymentSuccess =  '1' AND
    (SerialType IN ('Var1','Var2') 
    OR
    (SerialType IN ('Var3','Var4') 
       AND VerificationStatus IS NULL 
      OR VerificationStatus NOT IN ('Found', 'NotFound', 'NotVerified')))

Answer 2

首先，我想知道您的第一个查询是否确实应该是：

SELECT ID, SID, SerialNumber, SerialType
FROM orders
WHERE paymentStatus =  'Completed' AND paymentSuccess =  '1' AND
      (VerificationStatus IS NULL OR VerificationStatus NOT IN ('Found', 'NotFound', 'NotVerified'));

注意括号。

其次，我怀疑您只想第二次使用更高级的过滤。 看起来像：

SELECT ID, SID, SerialNumber, SerialType
FROM orders
WHERE (SerialType IN ('Var1', 'Var2') AND paymentStatus =  'Completed' AND paymentSuccess =  '1') OR
      (SerialType IN ('Var3', 'Var4') AND paymentStatus =  'Completed' AND paymentSuccess =  '1' AND 
       VerificationStatus IS NULL OR VerificationStatus NOT IN ('Found', 'NotFound', 'NotVerified')
      )

这又可以简化为：

WHERE paymentStatus =  'Completed' AND paymentSuccess =  '1' AND
      (SerialType IN ('Var1', 'Var2') OR
       SerialType IN ('Var3', 'Var4') AND VerificationStatus IS NULL OR VerificationStatus NOT IN ('Found', 'NotFound', 'NotVerified')
      )