IT 이야기

1 ÷ 0은 전산을 하는 사람들은 에러 처리를 한다.

1.  [user_id],[account_seq] 필드에서 중복행 찾기

SELECT [user_id],[account_seq], count(*) AS insertCount
FROM [dbo].[tbl_Assign]
GROUP BY [user_id],[account_seq]
HAVING count(*) > 1

2.  [user_id],[account_seq] 필드에서 가장 큰 seq 값 찾기

SELECT MAX(seq), [user_id],[account_seq], count(*) AS insertCount
FROM [dbo].[tbl_Assign]
GROUP BY [user_id],[account_seq]
HAVING count(*) > 1

3.  중복된 행 중 seq 가 가장 큰 값을 제외한 값 select

SELECT a.seq AS seq
FROM [dbo].[tbl_Assign] A 
INNER JOIN ( SELECT MAX(seq) as seq, [user_id],[account_seq], count(*) AS insertCount
		    FROM [dbo].[tbl_Assign]
		    GROUP BY [user_id],[account_seq]
                    HAVING count(*) >1 ) B
ON A.[user_id] = B.[user_id] and A.[account_seq] = B.[account_seq] and A.seq <> B.seq

4.  중복된 행 중 seq 가 가장 큰 값을 제외한 값 delete

DELETE FROM [dbo].[tbl_Assign]
WHERE seq IN (SELECT a.seq AS seq
                       FROM [dbo].[tbl_Assign] A 
                       INNER JOIN ( SELECT MAX(seq) as seq, [user_id],[account_seq], count(*) AS insertCount
                                           FROM [dbo].[tbl_Assign]
                                           GROUP BY [user_id],[account_seq]
                                           HAVING count(*) > 1) B
ON A.[user_id] = B.[user_id] and A.[account_seq] = B.[account_seq] and A.seq <> B.seq )

/*Perform a 'USE ' to select the database in which to run the script.*/
-- Declare variables
SET NOCOUNT ON;

DECLARE @tablename varchar(255);
DECLARE @execstr varchar(400);
DECLARE @objectid int;
DECLARE @indexid  int;
DECLARE @frag decimal;
DECLARE @maxfrag decimal;

-- Decide on the maximum fragmentation to allow for.
SELECT @maxfrag = 30.0;

-- Declare a cursor.
DECLARE tables CURSOR FOR
SELECT TABLE_SCHEMA + '.' + TABLE_NAME
FROM INFORMATION_SCHEMA.TABLES
WHERE TABLE_TYPE = 'BASE TABLE';

-- Create the table.
CREATE TABLE #fraglist (
                         ObjectName char(255),
			ObjectId int,
			IndexName char(255),
			IndexId int,
			Lvl int,
			CountPages int,
			CountRows int,
			MinRecSize int,
			MaxRecSize int,
			AvgRecSize int,
			ForRecCount int,
			Extents int,
			ExtentSwitches int,
			AvgFreeBytes int,
			AvgPageDensity int,
			ScanDensity decimal,
			BestCount int,
			ActualCount int,
			LogicalFrag decimal,
			ExtentFrag decimal);

-- Open the cursor.
OPEN tables;

-- Loop through all the tables in the database.
FETCH NEXT
FROM tables
INTO @tablename;

WHILE @@FETCH_STATUS = 0
BEGIN
-- Do the showcontig of all indexes of the table
INSERT INTO #fraglist
EXEC ('DBCC SHOWCONTIG (''' + @tablename + ''')
WITH FAST, TABLERESULTS, ALL_INDEXES, NO_INFOMSGS');
FETCH NEXT
FROM tables
INTO @tablename;
END;

-- Close and deallocate the cursor.
CLOSE tables;
DEALLOCATE tables;

-- Declare the cursor for the list of indexes to be defragged.
DECLARE indexes CURSOR FOR
SELECT ObjectName, ObjectId, IndexId, LogicalFrag
FROM #fraglist
WHERE LogicalFrag >= @maxfrag
AND INDEXPROPERTY (ObjectId, IndexName, 'IndexDepth') > 0;

-- Open the cursor.
OPEN indexes;

-- Loop through the indexes.
FETCH NEXT
FROM indexes
INTO @tablename, @objectid, @indexid, @frag;

WHILE @@FETCH_STATUS = 0
BEGIN
PRINT 'Executing DBCC INDEXDEFRAG (0, ' + RTRIM(@tablename) + ',
' + RTRIM(@indexid) + ') - fragmentation currently '
+ RTRIM(CONVERT(varchar(15),@frag)) + '%';
SELECT @execstr = 'DBCC INDEXDEFRAG (0, ' + RTRIM(@objectid) + ',
' + RTRIM(@indexid) + ')';
EXEC (@execstr);

FETCH NEXT
FROM indexes
INTO @tablename, @objectid, @indexid, @frag;
END;

-- Close and deallocate the cursor.
CLOSE indexes;
DEALLOCATE indexes;

-- Delete the temporary table.
DROP TABLE #fraglist;
GO