我知道这已经很晚了，但是我也遇到了类似的情况。我需要一个“ Like In”运算符来存储一组存储过程，该存储过程接受许多参数，然后使用这些参数来聚合来自多个RDBMS系统的数据，因此，RDBMS特定的技巧将不起作用，但是该存储过程和任何功能它将在MS SQL Server上运行，因此我们可以使用T-SQL来为每个RDBMS生成完整的SQL语句，但是输出必须与RDBMS完全无关。
这就是我目前想将带分隔符的字符串（例如存储过程中的参数）转换为SQL块的想法。我称其为“喜欢”的“地衣”。得到它？
地衣
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =======================================================================
-- Lichen - Scalar Valued Function
-- Returns nvarchar(512) of "LIKE IN" results. See further documentation.
-- CREATOR: Norman David Cooke
-- CREATED: 2020-02-05
-- UPDATED:
-- =======================================================================
CREATE OR ALTER FUNCTION Lichen
(
-- Add the parameters for the function here
@leadingAnd bit = 1,
@delimiter nchar(1) = ';',
@colIdentifier nvarchar(64),
@argString nvarchar(256)
)
RETURNS nvarchar(512)
AS
BEGIN
-- Declare the return variable here
DECLARE @result nvarchar(512)
-- set delimiter to detect (add more here to detect a delimiter if one isn't provided)
DECLARE @delimit nchar(1) = ';'
IF NOT @delimiter = @delimit
SET @delimit = @delimiter
-- check to see if we have any delimiters in the input pattern
IF CHARINDEX(@delimit, @argString) > 1 -- check for the like in delimiter
BEGIN -- begin 'like in' branch having found a delimiter
-- set up a table variable and string_split the provided pattern into it.
DECLARE @lichenTable TABLE ([id] [int] IDENTITY(1,1) NOT NULL, line NVARCHAR(32))
INSERT INTO @lichenTable SELECT * FROM STRING_SPLIT(@argString, ';')
-- setup loop iterators and determine how many rows were inserted into lichen table
DECLARE @loopCount int = 1
DECLARE @lineCount int
SELECT @lineCount = COUNT(*) from @lichenTable
-- select the temp table (to see whats inside for debug)
--select * from @lichenTable
-- BEGIN AND wrapper block for 'LIKE IN' if bit is set
IF @leadingAnd = 1
SET @result = ' AND ('
ELSE
SET @result = ' ('
-- loop through temp table to build multiple "LIKE 'x' OR" blocks inside the outer AND wrapper block
WHILE ((@loopCount IS NOT NULL) AND (@loopCount <= @lineCount))
BEGIN -- begin loop through @lichenTable
IF (@loopcount = 1) -- the first loop does not get the OR in front
SELECT @result = CONCAT(@result, ' ', @colIdentifier, ' LIKE ''', line, '''') FROM @lichenTable WHERE id = @loopCount
ELSE -- but all subsequent loops do
SELECT @result = CONCAT(@result, ' OR ', @colIdentifier, ' LIKE ''', line, '''') FROM @lichenTable WHERE id = @loopCount
SET @loopcount = @loopCount + 1 -- increment loop
END -- end loop through @lichenTable
-- set final parens after lichenTable loop
SET @result = CONCAT(@result, ' )')
END -- end 'like in' branch having found a delimiter
ELSE -- no delimiter was provided
BEGIN -- begin "no delimiter found" branch
IF @leadingAnd = 1
SET @result = CONCAT(' AND ', @colIdentifier, ' LIKE ''' + @argString + '''')
ELSE
SET @result = CONCAT(' ', @colIdentifier, ' LIKE ''' + @argString + '''')
END -- end "no delimiter found" branch
-- Return the result of the function
RETURN @result
END -- end lichen function
GO
可能已经计划了定界符检测，但目前它默认为分号，因此您可以将其default放在其中。这可能有错误。该@leadingAnd参数只是一个位值，用于确定是否要在块的前面放置一个前置的“ AND”，以便与其他WHERE子句添加项很好地配合。
用法示例（在argString中带有定界符）
SELECT [dbo].[Lichen] (
default -- @leadingAND, bit, default: 1
,default -- @delimiter, nchar(1), default: ';'
,'foo.bar' -- @colIdentifier, nvarchar(64), this is the column identifier
,'01%;02%;%03%' -- @argString, nvarchar(256), this is the input string to parse "LIKE IN" from
)
GO
将返回一个nvarchar（512），其中包含：
AND ( foo.bar LIKE '01%' OR foo.bar LIKE '02%' OR foo.bar LIKE '%03%' )
如果输入不包含定界符，它将也跳过该块：
用法示例（argString中没有定界符）
SELECT [dbo].[Lichen] (
default -- @leadingAND, bit, default: 1
,default -- @delimiter, nchar(1), default: ';'
,'foo.bar' -- @colIdentifier, nvarchar(64), this is the column identifier
,'01%' -- @argString, nvarchar(256), this is the input string to parse "LIKE IN" from
)
GO
将返回一个nvarchar（512），其中包含：
AND foo.bar LIKE '01%'
我将继续对此进行研究，因此，如果我忽略了某些内容（显而易见或其他明显的内容），请随时发表评论或寻求帮助。