我正在努力更好地理解基于集合的逻辑并简化我正在处理的一段代码。以下是我目前正在使用的一个示例（目前由于很快就会显现的原因而无效）：
SELECT
userid,
rn = ROW_NUMBER() OVER (ORDER BY username)
FROM user
WHERE username like 'test%'
WHILE rn between 1 and 100
<RUN SP USING INFORMATION>
WHILE rn between 101 and 200
<RUN SP WITH DIFFERENT INFORMATION>
出于示例的目的，假设有200行符合SELECT语句中的条件。还假设我们无法对user表进行更改。我的问题是，如果不使用临时表而没有（希望）使用WHILE循环，我还能怎样处理这个？
请注意，引用的SP是一个相当复杂的存储过程，需要使用该SELECT语句中的信息。我可以通过使用临时表并逐行进行处理，但我正在尝试了解其他方法，我可以批量处理它。
答案 0 :(得分：3)
几年前，我写了一个基于SQL的实用程序专门用于解决这样的需求。本文详细介绍了其他网站：http://www.sqlservercentral.com/scripts/Administration/69737/。 （如果你愿意，我也可以在这里加入，但它相当长）
请注意以下内容：
您可能会使用此工具解决您的问题：
EXECUTE OVER_SET '
IF {rn} between 1 and 100
<RUN SP USING INFORMATION>
IF {rn} between 101 and 200
<RUN SP WITH DIFFERENT INFORMATION>
',
@from = '
(SELECT
userid,
rn = ROW_NUMBER() OVER (ORDER BY username)
FROM user
WHERE username like ''test%'') aa '
@subs1 = '{userid}=userid',
@subs2 = '{rn}=rn',
@quote = '"' -- Allows you to use (") for quotes inside the 1st string
;
由于这是一个注册网站，我发布下面的代码（长）：
CREATE PROC
OVER_SET (
@command AS NVARCHAR(MAX), -- Template SQL command
@from AS NVARCHAR(MAX), -- FROM..WHERE clause string
@subs1 AS NVARCHAR(MAX) = N'', -- Substitution parameters, these are
@subs2 AS NVARCHAR(MAX) = N'', -- of the form "<find>=<repl>" where:
@subs3 AS NVARCHAR(MAX) = N'', -- <find> will be searched for in @command, and
-- <repl> will replace it, if it was found
-- (typically, <repl> should be a column name
-- returned by the FROM clause)
@print AS BIT = 1, -- 0 = suppress PRINT of the SQL before executing
@catch AS VARCHAR(12) = 'continue',
-- TRY/CATCH option parameters. Choices are:
-- 'continue' on an error, print a message & continue
-- 'ignore' attempt to suppress all errors
-- 'fail' try to re-raise the error
-- 'none' no TRY/CATCH blocks
@use_db AS NVARCHAR(255) = N'', -- DB to switch to befor execution of the SQL text
@quote AS NVARCHAR(8) = N'' -- search for this character & replace with (').
)
AS
--
DECLARE @qt AS NVARCHAR(1), @cr AS NVARCHAR(1);
SELECT @qt = N'''', @cr = N'
';
DECLARE @find1 AS NVARCHAR(MAX), @prfx1 AS NVARCHAR(MAX), @sufx1 AS NVARCHAR(MAX)
DECLARE @find2 AS NVARCHAR(MAX), @prfx2 AS NVARCHAR(MAX), @sufx2 AS NVARCHAR(MAX)
DECLARE @find3 AS NVARCHAR(MAX), @prfx3 AS NVARCHAR(MAX), @sufx3 AS NVARCHAR(MAX)
DECLARE @prtst AS NVARCHAR(MAX), @prfxC AS NVARCHAR(MAX), @sufxC AS NVARCHAR(MAX)
DECLARE @newdb AS NVARCHAR(MAX), @declr AS NVARCHAR(MAX)
DECLARE @NewCmd AS NVARCHAR(MAX), @GenCmd AS NVARCHAR(MAX)
;
SELECT
@find1 = CASE WHEN @subs1 = N'' THEN N'' ELSE LEFT(@subs1,CHARINDEX(N'=',@subs1)-1) END,
@prfx1 = CASE WHEN @subs1 = N'' THEN N'' ELSE N'REPLACE(' END,
@sufx1 = CASE WHEN @subs1 = N'' THEN N'' ELSE N',@find1,'+RIGHT(@subs1,LEN(@subs1)-CHARINDEX(N'=',@subs1))+N')' END,
@find2 = CASE WHEN @subs2 = N'' THEN N'' ELSE LEFT(@subs2,CHARINDEX(N'=',@subs2)-1) END,
@prfx2 = CASE WHEN @subs2 = N'' THEN N'' ELSE N'REPLACE(' END,
@sufx2 = CASE WHEN @subs2 = N'' THEN N'' ELSE N',@find2,'+RIGHT(@subs2,LEN(@subs2)-CHARINDEX(N'=',@subs2))+N')' END,
@find3 = CASE WHEN @subs3 = N'' THEN N'' ELSE LEFT(@subs3,CHARINDEX(N'=',@subs3)-1) END,
@prfx3 = CASE WHEN @subs3 = N'' THEN N'' ELSE N'REPLACE(' END,
@sufx3 = CASE WHEN @subs3 = N'' THEN N'' ELSE N',@find3,'+RIGHT(@subs3,LEN(@subs3)-CHARINDEX(N'=',@subs3))+N')' END,
@newdb = CASE WHEN @use_db= N'' THEN N'' ELSE N'USE [' + @use_db + N'];' + @cr END,
@declr = N'DECLARE @_Num AS INT, @_Lin AS INT, @_Err AS NVARCHAR(MAX), @_Msg AS NVARCHAR(MAX);'+@cr
;
;WITH
[base] AS (SELECT cmd = @command),
[quot] AS (SELECT cmd = CASE @quote WHEN N'' THEN cmd ELSE REPLACE(cmd, @quote, @qt) END FROM [base]),
[dble] AS (SELECT cmd = N'N'+@qt+REPLACE(cmd, @qt, @qt+@qt)+@qt FROM [quot]),
[prnt] AS (SELECT cmd = CASE @print WHEN 1 THEN N' PRINT '+cmd+';'+@cr ELSE N'' END
+ N' EXEC('+cmd+N');' FROM [dble]),
[ctch] AS (SELECT cmd =
CASE @catch WHEN N'none' THEN cmd
ELSE N'BEGIN TRY'+@cr+cmd+@cr+N'END TRY'+@cr+N'BEGIN CATCH'+@cr
+ N' SELECT @_Num=ERROR_NUMBER(), @_Lin=ERROR_LINE(), @_Err=ERROR_MESSAGE()'+@cr
+ CASE @catch
WHEN N'continue' THEN
N' SELECT @_msg=''Continuing after Error(''+CAST(@_Num AS NVARCHAR)+'') at Line ''+CAST(@_Lin AS NVARCHAR)+'''
+@cr+' ''+@_Err;'+@cr
+N' PRINT @_msg; '+@cr
+N' PRINT '' ''; '+@cr
WHEN N'ignore' THEN N' -- ignore = do nothing'+@cr
WHEN N'fail' THEN
N' SELECT @_msg=''Failing after Error(''+CAST(@_Num AS NVARCHAR)+'') at Line ''+CAST(@_Lin AS NVARCHAR)+'''
+@cr+' ''+@_Err;'+@cr
+N' RAISERROR(@_Num, 16, 1);'+@cr
+N' PRINT '' ''; '+@cr
ELSE N' --BAD else branch, shouldnt get here' END
+ N'END CATCH;' END FROM [prnt])
SELECT
@NewCmd = @prfx1+@prfx2+@prfx3+ N'@command' +@sufx1+@sufx2+@sufx3,
@command = cmd + @cr
FROM [ctch]
;
SELECT @GenCmd = '
DECLARE @sql AS NVARCHAR(MAX); SET @sql = '''+@newdb+ +@declr+ '''
;WITH
[-@from] AS ( SELECT * FROM ' +@from+ ' )
, [-@subs] AS ( SELECT [-NewCmd] = ' +@NewCmd+ ' FROM [-@from] )
, [-@print] AS ( SELECT [-NewCmd] = [-NewCmd] FROM [-@subs] )
SELECT
@sql = @sql + ''
'' + [-NewCmd]
FROM [-@subs]
;
EXEC sp_executesql @sql;
'
;
EXEC sp_executesql @GenCmd
, N'@command NVARCHAR(MAX), @from NVARCHAR(MAX), @find1 NVARCHAR(MAX), @find2 NVARCHAR(MAX), @find3 NVARCHAR(MAX)'
, @command, @from, @find1, @find2, @find3
;
以下是后评论，其中包括一些例子：
Example Usages
1) INSERT..EXECute:
Demonstrates capturing the SELECT output from an EXECUTE OVER_SET that
searches every database in the SQL Server Instance for routines with
the work "cursor" in them.
--
CREATE TABLE #temp (DB sysname, [Schema] sysname, Routine sysname);
INSERT INTO #temp
EXECUTE OVER_SET '
SELECT ROUTINE_CATALOG, ROUTINE_SCHEMA, ROUTINE_NAME
FROM [{db}].INFORMATION_SCHEMA.ROUTINES
WHERE ROUTINE_DEFINITION like "%cursor%"',
@from = 'sys.sysdatabases WHERE dbid > 4',
@subs1 = '{db}=name',
@quote = '"'
;
SELECT * from #temp;
DROP table #temp;
--
The @from argument returns the list of non-system databases in the server,
and the @susbs1 argument "{db}=name" tells it to replace every instance
of "{db}" in the command strings with the value of the [name] column (from
sys.sysdatabases). Note also the @quote argument's value (") allows us to
use a single quotation mark in the quoted command text instead of having
to use double apostrophes (ie, ' "%cursor%" ', instead of ' ''%cursor%'' ').
--======
2) Nested Example:
Demonstrates, nesting OVER_SET execution to operate against the combination
of to different sets, the second dependent on the first. Specifically,
it searches every non-system database for every user that is a windows
user or group, and then attempts to map them back to a server Login of
the same name.
--
EXECUTE OVER_SET '
EXECUTE OVER_SET "
ALTER USER [{name}] WITH LOGIN = [{name}];
PRINT `USER {name} has been mapped to its Login.`;",
@from = "sys.database_principals
WHERE ( type_desc = ""WINDOWS_GROUP"" OR type_desc = ""WINDOWS_USER"" )
AND name NOT like ""%dbo%"" AND name NOT LIKE ""%#%"" ",
@use_db = "{db}",
@subs1 = "{name}=name",
@catch = "continue",
@print = 1,
@quote = "`";
',
@from = 'sys.sysdatabases
WHERE dbid > 4',
@subs1 = '{db}=name',
@catch = 'continue',
@print = 0,
@quote = '"';
--
The outer OVER_SET uses the @from argument to return the list of all databases
which the @subs1 argument "{db}=name", uses to modify the inner OVER_SET
commands @use_db argument, cuasing the inner execution to USE [{db}} to each
database in turn. The inner execution's @from argument returns the list
of database users that are WINDOWS_* user or group, and the @subs1 ({name}=name)
cause the "{name}" token to be replaced with the value of the [name] column
from the database_principals table.
Note that two different @quote characters are used ( ("), then (`) ), removing
the need for double or even quadruple apostrophes in the inner command text.
(also note, that the @from argument text does not benefit from this, and can
only use the outer command quote (") becuase it is part of the outer command
text argument.
答案 1 :(得分：1)
您无法将存储过程作为另一个查询的一部分进行调用，因此在不重写存储过程的情况下，无法执行基于集合的操作。
答案 2 :(得分：0)
是否可以使用SP的UDFs instad？在这种情况下，您可以一次性使用SELECT语句中的参数包含UDF。显然UDF有局限性，但我想这取决于你的SP的复杂性。