在 T-SQL 中实现和应用字符串拆分

Question

我在 T-SQL 中有这个语句。

SELECT Bay From TABLE where uid in (
    select B_Numbers from Info_Step WHERE uid = 'number'
)

我从TABLE 中选择“多个”BAYs，其中他们的uid 等于这样的一串数字：

B_Numbers = 1:45:34:98

因此，我应该从 TABLE 中选择 4 个不同的 BAYs。我基本上需要将字符串 1:45:34:98 拆分为 4 个不同的数字。

我认为 Split() 会起作用，但它不起作用，我得到一个语法错误。 T-SQL 大神们的任何想法都会很棒！

Answer 1

这是一个拆分函数的实现，它以表格形式返回数字列表：

http://rbgupta.blogspot.com/2007/03/split-function-tsql.html

看起来这会让你上路……

Answer 2

这是一种使用辅助数字表来解析输入字符串的方法。可以轻松地将逻辑添加到返回表的函数中。然后可以连接该表以查找正确的行。

第 1 步：创建数字表

SET NOCOUNT ON
GO

IF EXISTS
(
    SELECT  1
    FROM    INFORMATION_SCHEMA.TABLES
    WHERE       TABLE_NAME  = 'Numbers'
            AND     TABLE_SCHEMA    = 'dbo'
            AND     TABLE_TYPE  = 'BASE TABLE'
)
BEGIN
    DROP TABLE dbo.Numbers
END
GO

CREATE TABLE dbo.Numbers
(
    Number smallint  IDENTITY(1, 1) PRIMARY KEY
)
GO

WHILE 1 = 1
BEGIN
    INSERT INTO dbo.Numbers DEFAULT VALUES

    IF SCOPE_IDENTITY() = 32767 
    BEGIN
        BREAK
    END
END
GO

第 2 步：解析输入字符串

CREATE FUNCTION dbo.ParseString(@input_string varchar(8000), @delim varchar(8000) = " ")
RETURNS TABLE
AS RETURN
(
    SELECT Number 
    FROM dbo.Numbers
    WHERE CHARINDEX 
    ( 
        @delim + CONVERT(VARCHAR(12),Number) + @delim, 
        @delim + @input_string + @delim 
    ) > 0 
)
GO

**EXAMPLE**
SELECT * FROM dbo.ParseString('1:45:34:98',':')

第 3 步：使用您想要/需要的结果

Number
------
1
34
45
98

端到端示例

创建返回适当 BNumber 的函数（当然更改它以使用注释掉的 SQL）

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE FUNCTION dbo.GetBNumber (@uid int)
RETURNS VARCHAR(8000) 
AS
BEGIN
    RETURN '1:45:34:98'
    --select B_Numbers from Info_Step WHERE uid = @uid
END
GO

使用使用函数返回想要的结果

-- Using Test Data
SELECT N.Number FROM Numbers N
JOIN dbo.ParseString(dbo.GetBNumber(12345),':') Q ON Q.Number = N.Number

-- Using Your Data (Untested but should work.)
SELECT N.Bay
FROM TABLE N
JOIN dbo.ParseString(dbo.GetBNumber(ENTER YOU NUMBER HERE),':') Q ON Q.Number = N.uid

结果

Number
------
1
34
45
98

Answer 3

您应该将数组保留为行，但如果我理解您的问题，我认为这会起作用。

SELECT 
    Bay 

From 
    TABLE
    join  Info_Step 
    on B_Numbers like '%'+ uid  +'%'

where 
    Info_Step.uid = 'number'

由于 like 运算符，此查询将执行全表扫描。

Answer 4

您可以做的是遍历B_Numbers 条目并在: 上进行自己的拆分将这些条目插入到临时表中，然后执行您的查询。

DECLARE @i             int
DECLARE @start         int
DECLARE @B_Numbers     nvarchar(20)
DECLARE @temp          table (
    number nvarchar(10)
)

-- SELECT B_Numbers FROM Info_Step WHERE uid = 'number'
SELECT @B_Numbers = '1:45:34:98'

SET @i = 0
SET @start = 0

-- Parse out characters delimited by ":";  
-- Would make a nice user defined function.
WHILE @i < len(@B_Numbers)
BEGIN
    IF substring(@B_Numbers, @i, 1) = ':'
    BEGIN
        INSERT INTO @temp
        VALUES (substring(@B_Numbers, @start, @i - @start))
        SET @start = @i + 1
    END

    SET @i = @i + 1
END

-- Insert last item
INSERT INTO @temp
VALUES (substring(@B_Numbers, @start, @i - @start + 1))

-- Do query with parsed values
SELECT Bay FROM TABLE WHERE uid in (SELECT * FROM @temp)

Answer 5

你甚至可以试试这个

declare @str varchar(50)
set @str = '1:45:34:98'

;with numcte as(
select 1 as rn union all select rn+1 from numcte where rn<LEN(@str)),
getchars as(select 
ROW_NUMBER() over(order by rn) slno,
rn,chars from numcte 
cross apply(select SUBSTRING(@str,rn,1) chars)X where chars = ':') 

select top 1 
    Bay1 = SUBSTRING(@str,0,(select rn from getchars where slno = 1)) 
    ,Bay2 = SUBSTRING(@str,
            (select rn from getchars where slno = 1) + 1,
            (((select rn from getchars where slno = 2)-
            (select rn from getchars where slno = 1)
            )-1))
    ,Bay3 = SUBSTRING(@str,
            (select rn from getchars where slno = 2) + 1,
            (((select rn from getchars where slno = 3)-
            (select rn from getchars where slno = 2)
            )-1))
    ,Bay4 = SUBSTRING(@str,
            (select rn from getchars where slno = 3)+1,
            LEN(@str))
    from getchars 

输出：

Bay1    Bay2    Bay3    Bay4
1   45  34  98