Question

我正在尝试查找出现在给定数据库中多个表中的列。我已经成功创建了一个结果集，该结果集为列名，表名和其他排名列以及一个标志（0或1）提供了多次出现。

我只是想知道是否有可能根据最后一栏过滤此CTE

;with CTE as
(
    SELECT c.name AS ColName, t.name AS TableName, ROW_NUMBER() over (partition by c.name order by c.name) as NumberofOcuurance
    FROM sys.columns c
    JOIN sys.tables t 
    ON c.object_id = t.object_id    
)    
select *, 
    case
    when    LEAD(NumberofOcuurance,1) over (order by colName) = NumberofOcuurance then  0
    when    LEAD(NumberofOcuurance,1) over (order by colName) <> NumberofOcuurance then  1
    End as Morethan1    
from CTE

Answer 1

只需使用子查询/派生表，例如

WITH cte AS (
    SELECT c.[name] AS ColName, t.[name] AS TableName, ROW_NUMBER() OVER (PARTITION BY c.[name] ORDER BY c.[name]) AS NumberofOccurrance
    FROM sys.columns c
    INNER JOIN sys.tables t ON c.object_id = t.object_id
)
SELECT *
FROM (
    SELECT * 
        , CASE
        WHEN LEAD(NumberofOccurrance, 1) OVER (ORDER BY colName) = NumberofOccurrance THEN 0
        WHEN LEAD(NumberofOccurrance, 1) OVER (ORDER BY colName) <> NumberofOccurrance THEN 1
        END AS Morethan1
    FROM cte 
) x
WHERE x.Morethan1 = 1;

Answer 2

为什么不只使用information_schema视图？

select column_name, string_agg(table_name, ',') as table_names
from information_schema.columns
group by column_name
having count(*) > 1

根据计算列过滤CTE的结果集

2 个答案: