Question

我有一个嵌入了子查询的查询。我想使用like运算符而不是IN运算符。 IN运算符工作正常，但不能提供我需要的所有结果......

我已尝试过以下查询，但获取：

子查询返回的值超过1。当子查询遵循=，！=，＆lt;，＆lt; =，＆gt;，＆gt; =或子查询用作表达式时，不允许这样做。

查询：

SELECT a.Name, 
  CONVERT(nvarchar(50),RTRIM(b.[num])) + ' - ' + CONVERT(nvarchar(50),b.name) AS 'My Code'
FROM firstTable a 
left join secondTable b ON (a.id = b.id)
WHERE a.Name like (select RTRIM(LTRIM('%' + [Customer_Name] + '%')) FROM thirdTable)

Answer 1

您可以使用此查询，但由于这是使用LIKE运算符进行连接，因此性能可能不是很好：

SELECT a.Name, CONVERT(nvarchar(50),RTRIM(b.[num])) + ' - ' + CONVERT(nvarchar(50),b.name) AS 'My Code'
 FROM firstTable a 
     left join secondTable b ON (a.id = b.id)
     INNER JOIN thirdTable c ON a.Name LIKE '%' + c.[Customer_Name] + '%'

Answer 2

您无法使用in进行部分匹配，但可以在like子句中使用on。
试试这个：

SELECT a.Name, 
  CONVERT(nvarchar(50),RTRIM(b.[num])) + ' - ' + CONVERT(nvarchar(50),b.name) AS 'My Code'
FROM firstTable a 
Inner join third table on a.name like rtrim(ltrim('%'+ customer_name +'%'))
left join secondTable b ON (a.id = b.id)

Answer 3

这将返回多个不满足查询的记录

WHERE a.Name like (select RTRIM(LTRIM('%' + [Customer_Name] + '%')) FROM thirdTable)

而不是你可以使用

SELECT a.Name, CONVERT(nvarchar(50),RTRIM(b.[num])) + ' - ' + CONVERT(nvarchar(50),b.name) AS 'My Code'
 FROM firstTable a 
     left join secondTable b ON (a.id = b.id)
     INNER JOIN thirdTable c ON a.Name LIKE '%' + c.[Customer_Name] + '%'

OR

SELECT a.Name, 
  CONVERT(nvarchar(50),RTRIM(b.[num])) + ' - ' + CONVERT(nvarchar(50),b.name) AS 'My Code'
FROM firstTable a 
left join secondTable b ON (a.id = b.id)
WHERE a.Name like (select RTRIM(LTRIM('%' + c.[Customer_Name] + '%')) FROM thirdTable c where c.id = @id)

OR

SELECT a.Name, 
  CONVERT(nvarchar(50),RTRIM(b.[num])) + ' - ' + CONVERT(nvarchar(50),b.name) AS 'My Code'
FROM firstTable a 
left join secondTable b ON (a.id = b.id)
WHERE a.Name like (select top 1 RTRIM(LTRIM('%' + [Customer_Name] + '%')) FROM thirdTable)

像子查询SQL Server中的运算符

3 个答案: