1

我的数据库的每个表中的每一行都有一个 RowUpdateDateTime 列，这是更新或插入特定行的最新时间。每个表中还有 1 到 7 个不同的数据源；有的有1个，有的有7个。

基本上，我试图遍历这些表，并在适用的情况下为这些表中的每一个找到这些源中的每一个的最新 RowUpdateDateTime。这是我和一位同事为此写的很长的查询。它是功能性的，但我怀疑可以重写。

IF OBJECT_ID('tempdb..#SourceID') IS NOT NULL
BEGIN
    DROP TABLE #SourceID
END

IF OBJECT_ID('tempdb..#Tables') IS NOT NULL
BEGIN
    DROP TABLE #Tables
END

IF OBJECT_ID('tempdb..#UpdateCount') IS NOT NULL
BEGIN
    DROP TABLE #UpdateCount
END

GO


CREATE TABLE #SourceID
    (
    SourceID varchar(4),
    CounterID int
    )

INSERT INTO #SourceID (SourceID,CounterID)
SELECT 'ZEND',1
UNION ALL
SELECT 'ABC',2
UNION ALL
SELECT 'DEF',3
UNION ALL 
SELECT 'GHI',4
UNION ALL
SELECT 'JKL',5
UNION ALL
SELECT 'MNO',6
UNION ALL
SELECT 'PQR',7
UNION ALL
SELECT 'STU',8

GO  

CREATE TABLE #Tables
    (
    Name varchar(100),
    CounterID int
    )

INSERT INTO #Tables (Name,CounterID)
SELECT 'livendb..Table1',1
UNION ALL
SELECT 'livendb..Table2',2
UNION ALL
SELECT 'livendb..Table3',3
UNION ALL
SELECT 'livendb..Table4',4
UNION ALL
SELECT 'livendb..Table5',5
UNION ALL
SELECT 'livendb..Table6',6
UNION ALL
SELECT 'livendb..Table7',7
UNION ALL
SELECT 'livefdb..Table8',8
UNION ALL
SELECT 'livefdb..Table9',9
UNION ALL
SELECT 'livefdb..Table10',10
UNION ALL
SELECT 'livefdb..Table11',11
UNION ALL
SELECT 'livefdb..Table12',12
UNION ALL
SELECT 'livefdb..Table13',13

GO

Declare @counter varchar(10)
Declare @tablename varchar(100)
Declare @query varchar(1100)
Declare @sourceid varchar(4)
Declare @sourcecounter varchar(10) 


CREATE TABLE #UpdateCount
    (
    SourceID varchar(3),
    TableName Varchar(100),
    MaxRowUpdateDateTime datetime,
    --TotalRowCount int
    )


SET @sourcecounter = (SELECT COUNT(*) FROM #SourceID)
SET @counter = (SELECT COUNT (*) FROM #Tables)

WHILE @sourcecounter >= 0
BEGIN
    SET @sourceid = (SELECT SourceID FROM #SourceID WHERE CounterID = (@sourcecounter))
        IF @sourceid <> 'ZEND'
        BEGIN
                WHILE @counter >=0
                BEGIN
                    SET @tablename = (SELECT Name FROM #Tables WHERE CounterID = (@counter))

                    IF @counter <> 0
                    BEGIN
                    SET @query = 'INSERT INTO #UpdateCount (SourceID,TableName,MaxRowUpdateDateTime)
                                VALUES (
                                        (SELECT SourceID FROM #SourceID WHERE CounterID = '+@sourcecounter+')
                                        ,(SELECT Name FROM #Tables WHERE CounterID = '+@counter+')
                                        ,(SELECT MAX(RowUpdateDateTime) FROM '+@tablename+' WHERE SourceID = 
                                                        (SELECT SourceID FROM #SourceID WHERE CounterID = '+@sourcecounter+')))'

                    EXECUTE (@query)
                    END
                SET @counter = (@counter-1)
                END

        END

    SET @sourcecounter = (@sourcecounter-1)
    SET @counter = (SELECT COUNT (*) FROM #Tables)
END

        SELECT  SourceID
                ,SUBSTRING(TableName,10,22) as TableName
                ,MaxRowUpdateDateTime
                --,TotalRowCount
        FROM #UpdateCount 
            Where MaxRowUpdateDateTime IS NOT NULL
            ORDER BY TableName

DROP TABLE #Tables
DROP TABLE #UpdateCount
DROP TABLE #SourceID
4

1 回答 1

1

按照这个例子的模式，你可能会更好（因为代码更简单）。它不能回答您的整个问题（至少对我而言，在没有数据的情况下编写动态 SQL 非常困难）。

这应该为您提供一个良好的工作起点。

USE AdventureWorks2012
GO

DECLARE @Query VARCHAR(MAX) =''

;WITH Tables AS
(
    SELECT DISTINCT TABLE_NAME = '[' + TABLE_SCHEMA + ']' + '.' + '[' + TABLE_NAME + ']'
    FROM INFORMATION_SCHEMA.COLUMNS
    WHERE COLUMN_NAME = 'ModifiedDate'
)
SELECT  @Query  = @Query + 
'   SELECT   SourceTable    = '''+ TABLE_NAME + '''
            ,RecentMod      = MAX(ModifiedDate) 
    FROM ' + TABLE_NAME + ' UNION ALL'
FROM Tables

SET @Query = LEFT(@Query, LEN(@Query) - LEN(' UNION ALL'))

EXEC (@Query)

产生这样的结果；

SourceTable                                     |   RecentMod
===========================================================================
[dbo].[AWBuildVersion]                          |   2012-03-14 00:00:00.000
[dbo].[OLE DB Destination]                      |   2008-07-31 00:00:00.000
[HumanResources].[Department]                   |   2002-06-01 00:00:00.000
[HumanResources].[Employee]                     |   2009-01-26 09:17:08.637
[HumanResources].[EmployeeDepartmentHistory]    |   2007-12-15 00:00:00.000
[HumanResources].[EmployeePayHistory]           |   2008-07-31 00:00:00.000
[HumanResources].[JobCandidate]                 |   2008-01-23 18:32:21.313
[HumanResources].[Shift]                        |   2002-06-01 00:00:00.000
[HumanResources].[vJobCandidate]                |   2008-01-23 18:32:21.313
[Person].[Address]                              |   2008-07-31 00:00:00.000
[Person].[AddressType]                          |   2002-06-01 00:00:00.000
[Person].[BusinessEntity]                       |   2012-01-14 13:47:22.467
[Person].[BusinessEntityAddress]                |   2008-10-13 11:15:06.967
...
于 2013-01-10T21:31:00.617 回答