SQL Server存储过程循环通过逗号分隔列表

Question

是否可以创建一个存储过程，该存储过程将拆分逗号分隔的列表，然后遍历该列表并执行更新语句？

这只是运行在并行执行的数百个更新语句（长度在120,000个字符左右）中的3个更新：

UPDATE OPERATION 
SET START = '20151012', FINISH = '20151012' 
WHERE REF = '912^0^15'; 

UPDATE OPERATION 
SET START = '20151012', FINISH = '20151013' 
WHERE REF = '913^0^15'; 

UPDATE OPERATION 
SET START = '20151013', FINISH = '20151014' 
WHERE REF = '872^0^15'; 

我在想的是，将一个列表传递给过程，然后让它创建更新语句，从而将每次更新的时间从每条记录111个字符减少到大约30个字符。

我不知道如何在SQL Server中编写存储过程，但是在javascript中，我会这样做：

伪代码：

list = "'20151012','20151012','912^0^15'|'20151012', '20151013','913^0^15'|'20151013','20151014','872^0^15'"

for each list.split('|') as row
    cols = row.split(',')

    UPDATE OPERATION  
    SET START = 'cols[0]', FINISH = 'cols[1]' 
    WHERE REF = 'cols[2]';      

是否可以创建一个可以执行此操作的存储过程？

Answer 1

我根本不喜欢你的主意。 但是为了证明有可能，我准备了一个小演示：

现场演示

DECLARE @string NVARCHAR(MAX) = 
 '20151012,20151012,912^0^15|20151012, 20151013,913^0^15|20151013,20151014,872^0^15';

CREATE TABLE #OPERATION(START NVARCHAR(100), FINISH NVARCHAR(100), REF NVARCHAR(100));

INSERT INTO #OPERATION 
VALUES ('', '', '912^0^15'),
       ('', '', '913^0^15'),
       ('', '', '872^0^15');


WITH cte AS
(
SELECT  
xml_data = CAST(REPLACE(REPLACE('<d>'+REPLACE(REPLACE(@string,'|','</d><d>'), ',' ,'</e><e>') +'</d>', '</d>', '</e></d>'), '<d>', '<d><e>') AS XML)
) , cte2 AS (
SELECT record.r.value('e[1]', 'NVARCHAR(100)') AS [start],
       record.r.value('e[2]', 'NVARCHAR(100)') AS [finish],
       record.r.value('e[3]', 'NVARCHAR(100)') AS [ref]
FROM cte
CROSS APPLY xml_data.nodes('//d') AS record(r)
)
UPDATE o
SET Start  = c.[start]
   ,finish = c.[finish]
FROM #OPERATION o
JOIN cte2 c
  ON c.ref = o.ref;

SELECT *
FROM #Operation;

您可以使用@string是参数的存储过程对其进行包装。

StoredProcedureDemo

CREATE PROCEDURE dbo.my_custom_update
  @string NVARCHAR(MAX)
AS
BEGIN
SET NOCOUNT ON;

WITH cte AS
(
SELECT  
xml_data = CAST(REPLACE(REPLACE('<d>'+REPLACE(REPLACE(@string,'|','</d><d>'), ',' ,'</e><e>') +'</d>', '</d>', '</e></d>'), '<d>', '<d><e>') AS XML)
) , cte2 AS (
SELECT record.r.value('e[1]', 'NVARCHAR(100)') AS [start],
       record.r.value('e[2]', 'NVARCHAR(100)') AS [finish],
       record.r.value('e[3]', 'NVARCHAR(100)') AS [ref]
FROM cte
CROSS APPLY xml_data.nodes('//d') AS record(r)
)
UPDATE o
SET Start  = c.[start]
   ,finish = c.[finish]
FROM OPERATION o
JOIN cte2 c
  ON c.ref = o.ref;

END;
GO

Answer 2

尝试像这样使用XML

DECLARE     @list VARCHAR(MAX) = '''20151012'',''20151012'',''912^0^15''|''20151012'', ''20151013'',''913^0^15''|''20151013'',''20151014'',''872^0^15'''

SELECT      s.rowno
            , MAX(CASE WHEN s.colno = 1 THEN s.value END) AS start
            , MAX(CASE WHEN s.colno = 2 THEN s.value END) AS finish
            , MAX(CASE WHEN s.colno = 3 THEN s.value END) AS ref
FROM        (
            SELECT      c.rowno
                        , ROW_NUMBER() OVER (PARTITION BY c.rowno ORDER BY (SELECT 1))
                        , REPLACE(LTRIM(d.x.value('(./text())[1]', 'VARCHAR(MAX)')), '''', '')
            FROM        (
                        SELECT      ROW_NUMBER() OVER (ORDER BY (SELECT 1))
                                    , CONVERT(XML, '<i>' + REPLACE(b.x.value('(./text())[1]', 'VARCHAR(MAX)'), ',', '</i><i>') + '</i>')
                        FROM        ( 
                                    SELECT      CONVERT(XML, '<i>' + REPLACE(@list, '|', '</i><i>') + '</i>')
                                    ) a(x)
                        CROSS APPLY a.x.nodes('i') b(x)
                        ) c(rowno, x)
            CROSS APPLY c.x.nodes('i') d(x)
            ) s(rowno, colno, value)
GROUP BY    s.rowno