答案是規範化你的數據庫。
與此同時,在大型設備上執行更好的解決方法是使用臨時表。 (LIKE
搜索不能使用索引)
該方法還顯示了標準化數據和處理空白的一些步驟。
如果您沒有,請先創建一個"Tally Table"。這是一次性交易,Tally表格適用於allkinds的things。
/*--- Create a Tally table. This only needs to be done once.
Note that "Master.dbo.SysColumns" is in all SQL 2000 installations.
For SQL 2005, or later, use "master.sys.all_columns".
*/
SELECT TOP 11000 -- Adequate for most business purposes.
IDENTITY (INT, 1, 1) AS N
INTO
dbo.Tally
FROM
Master.dbo.SysColumns sc1,
Master.dbo.SysColumns sc2
--- Add a Primary Key to maximize performance.
ALTER TABLE dbo.Tally
ADD CONSTRAINT PK_Tally_N PRIMARY KEY CLUSTERED (N) WITH FILLFACTOR = 100
現在假設你的表是:
CREATE TABLE ListO_Codes (ID INT IDENTITY(1,1), Code VARCHAR(88))
INSERT INTO ListO_Codes (Code)
SELECT '123,456,789,12' UNION ALL
SELECT '456,073' UNION ALL
SELECT '69,76,56'
CREATE TABLE AnotherTable (ID INT IDENTITY(1,1), Ref VARCHAR(8), CodeWord VARCHAR (88))
INSERT INTO AnotherTable (Ref, CodeWord)
SELECT '12', 'Children' UNION ALL
SELECT '123', 'of' UNION ALL
SELECT '456', '-' UNION ALL
SELECT '789', 'sun,' UNION ALL
SELECT '073', 'see' UNION ALL
SELECT '56', 'your' UNION ALL
SELECT '69', 'time' UNION ALL
SELECT '76', 'has'
然後臨時表是:
CREATE TABLE #NORMALIZED_Data (LOD_id INT, Ref int) -- Make Ref varchar if it's not numeric
INSERT INTO
#NORMALIZED_Data (LOD_id, Ref)
SELECT
L.ID,
-- Split Code string using Tally table and Delimiters
LTrim (RTrim (SUBSTRING (',' + L.Code + ',', T.N+1, CHARINDEX (',', ',' + L.Code + ',', T.N+1) - T.N - 1)))
FROM
dbo.Tally T,
ListO_Codes L
WHERE
T.N < LEN (',' + L.Code + ',')
AND
SUBSTRING (',' + L.Code + ',', T.N, 1) = ','
--- Index for performance
CREATE CLUSTERED INDEX CL_NORMALIZED_Data_LOD_id_Ref
ON #NORMALIZED_Data (LOD_id, Ref) WITH FILLFACTOR = 100
然後搜索:
SELECT
L.ID,
L.Code,
A.Ref,
A.CodeWord
FROM
#NORMALIZED_Data N
INNER JOIN
ListO_Codes L ON N.LOD_id = L.ID
LEFT JOIN
AnotherTable A ON N.Ref = A.Ref
ORDER BY
L.ID,
A.Ref
而結果是:
ID Code Ref CodeWord
-- -------------- --- --------
1 123,456,789,12 12 Children
1 123,456,789,12 123 of
1 123,456,789,12 456 -
1 123,456,789,12 789 sun,
2 456,073 073 see
2 456,073 456 -
3 69,76,56 56 your
3 69,76,56 69 time
3 69,76,56 76 has