我有一个包含县名的表和另一个用于电子邮件地址的列。我想查找电子邮件地址中包含县名的所有记录。我已经尝试了LIKE
和CHARINDEX
,但我还没能按预期工作 - 甚至使用我在这个网站上找到的其他例子。
样本数据:
UserID email County
15854 [email protected] POLK
15018 [email protected] ADAIR
15020 [email protected] ADAIR
15022 [email protected] ADAIR
15024 [email protected] ADAMS
15026 [email protected] ADAMS
15028 [email protected] ALLAMAKEE
15030 [email protected] ALLAMAKEE
15032 [email protected] ALLAMAKEE
15034 [email protected] APPANOOSE
我尝试过的不同变体包括:
SELECT UserID , email , County
FROM #CountyRecorders
--WHERE email LIKE '%' + County + '%';
--WHERE County LIKE '%' + email + '%';
--WHERE CHARINDEX(email,County) > 0;
--WHERE CHARINDEX(County,email) > 0;
如何完成所需的结果集?谢谢,
这里的两个答案都可行 - 我实际上在WHERE子句中使用CHARINDEX看到了更好的性能,但这种情况很接近。出于性能原因,我将采用的方法是使用计算列并对其进行索引。这样您只需执行一次计算。使用@Shnugo的示例数据(转换为perm临时表进行测试):
-- Table DDL and sample data
CREATE TABLE #tbl
(
UserID INT,
email VARCHAR(100),
County VARCHAR(100),
CountyInEmail AS CAST(SIGN(CHARINDEX(County,email)) AS BIT) PERSISTED
);
INSERT INTO #tbl VALUES
(15854,'[email protected] ','POLK')
,(15018,'[email protected] ','ADAIR')
,(15020,'[email protected] ','ADAIR')
,(15022,'[email protected] ','ADAIR')
,(15024,'[email protected] ','ADAMS')
,(15026,'[email protected] ','ADAMS')
,(15028,'[email protected] ','ALLAMAKEE')
,(15030,'[email protected] ','ALLAMAKEE')
,(15032,'[email protected] ','ALLAMAKEE')
,(15034,'[email protected] ','APPANOOSE');
-- Index on the "CountyInEmail" field
CREATE NONCLUSTERED INDEX nc_County ON #tbl(CountyInEmail)
INCLUDE (UserID, email, County)
;
-- Note the execution plan here (nonclustered index seek = good)
SELECT t.UserID, t.email, t.County, t.CountyInEmail
FROM #tbl AS t
WHERE t.CountyInEmail = 1;
您应该只能使用CHARINDEX进行此操作
Select UserId, email, County
FROM #CountyRecorders
WHERE CHARINDEX(County,email) > 0
你的外壳虽然很重要
你没有说明预期的结果,但是 - 如果我做对了 - 你的一种方法应该正确返回。这对我有用:
DECLARE @tbl TABLE(UserID INT, email VARCHAR(100),County VARCHAR(100));
INSERT INTO @tbl VALUES
(15854,'[email protected] ','POLK')
,(15018,'[email protected] ','ADAIR')
,(15020,'[email protected] ','ADAIR')
,(15022,'[email protected] ','ADAIR')
,(15024,'[email protected] ','ADAMS')
,(15026,'[email protected] ','ADAMS')
,(15028,'[email protected] ','ALLAMAKEE')
,(15030,'[email protected] ','ALLAMAKEE')
,(15032,'[email protected] ','ALLAMAKEE')
,(15034,'[email protected] ','APPANOOSE');
SELECT *
FROM @tbl
WHERE eMail LIKE '%' + County + '%';
返回所有行 - “test”和“frontier.com”行除外。
什么可能会打扰:如果您的列在区分大小写的排序规则下,大写的ADAIR
与adair
不同。您可以尝试在两侧使用LOWER
或对COLLATE
应用不敏感的排序规则