问题：我有 100 个表，它们的全名、出生日期、电子邮件和 ID 可以有不同的列名。例如：表 1 全名为 Emp name、dob、work email 和 national id。表 2 可能有 Full Nm、出生日期、Wrk 电子邮件、NID，而表 3 可能有 Full Name、出生日期、Work Em、NatID 等..对于 10 个或更多不同的表
全名+出生日期被视为唯一列
我需要的是一个查询或一种自动方式来选择那些可能具有不同名称的列，并根据具有这些列及其值（全名、出生日期、工作电子邮件、国家 ID）的参考表查找这些列值) 如果我找到了匹配项，那么
期望的结果：我需要检索找到匹配的表名、找到匹配的列名、匹配的值，如果找不到匹配则返回“不匹配”
我尝试使用INFORMATION_SCHEMA.COLUMNS，但还没有运气。任何帮助将不胜感激
【问题讨论】：
标签： sql string-matching lookup-tables azure-sql-server
我认为您可以查看INFORMATION_SCHEMA.COLUMNS。除非我没跟着你，否则你一定能做到吗？
select c.COLUMN_NAME, IsNull(m.Found,'No Match') Matches
from INFORMATION_SCHEMA.COLUMNS c
outer apply (
select column_name + ' is in ' + table_name Found
from INFORMATION_SCHEMA.COLUMNS x
where x.COLUMN_NAME =c.COLUMN_NAME and x.TABLE_NAME !=c.TABLE_NAME
)m
where c.table_name='MasterList'
使用您想在其他表中定位的所有列变体创建您的 MasterList 表，然后这将列出数据库中的所有表以及匹配的列。
【讨论】：
如果它有 10 个表，那么大概您可以提前检查它们并知道您要查看哪些列。然后挑战是将所有这些组合到一个查询中。你可以用一堆 UNION 来做，像这样：
select [Emp name] as Name, [dob] as DateOfBirth, [work email] as Email, [national id] as ID, 'Table1' as TableName
from Table1
UNION
select [Full Nm] as Name, [date of birth] as DateOfBirth, [Wrk Email] as Email, [NID] as ID, 'Table2' as TableName
from Table2
UNION
select [Full Name] as Name, [birth date] as DateOfBirth, [Work Em] as Email, [NatID] as ID, 'Table3' as TableName
from Table3
UNION
--etc etc
注意我们如何添加一个 TableName 列来告诉我们每个项目来自哪个表。
要查询整个数据集，您需要将其声明为视图或类似的东西，或者将其嵌套在另一个 SELECT 中，如下所示：
select Name, DateOfBirth, Email, ID, TableName
from (
select [Emp name] as Name, [dob] as DateOfBirth, [work email] as Email, [national id] as ID, 'Table1' as TableName
from Table1
UNION
select [Full Nm] as Name, [date of birth] as DateOfBirth, [Wrk Email] as Email, [NID] as ID, 'Table2' as TableName
from Table2
UNION
select [Full Name] as Name, [birth date] as DateOfBirth, [Work Em] as Email, [NatID] as ID, 'Table3' as TableName
from Table3
UNION
--etc etc
) giveitaname
WHERE [Name] = 'Joe Bloggs' and [DateOfBirth] = '01/Feb/1999'
【讨论】：