SQL: 根据给定的分隔符，分解字符串

如果有一个字符串 eg: "sun,star,moon,clouds",想要在MS SQL中根据给定的分隔符','把这个字符串分解成各个元素[sun] [star] [moon] [clouds]，如何实现呢？为此，创建一个Function,代码如下:

CREATE FUNCTION [ dbo ]. [ Split_StrByDelimiter ]( @String VARCHAR( 8000), @Delimiter CHAR( 1))
   RETURNS @temptable TABLE (items VARCHAR( 8000))
AS
     BEGIN
      DECLARE @idx INT
     DECLARE @slice VARCHAR( 8000)

     SELECT @idx = 1
          IF len( @String) < 1 OR @String IS NULL   RETURN

       while @idx != 0
        BEGIN
          SET @idx = charindex( @Delimiter, @String)
          IF @idx != 0
              SET @slice = LEFT( @String, @idx - 1)
         ELSE
              SET @slice = @String

          IF( len( @slice) > 0)
             INSERT INTO @temptable(Items) VALUES( @slice)

          SET @String = RIGHT( @String, len( @String) - @idx)
           IF len( @String) = 0 break
      END
    RETURN
END

示例：如果输入

SELECT * FROM dbo.Split_StrByDelimiter( ' sun,star,moon,clouds ', ' , ')

结果返回

sun

star

moon

clouds

在上面的代码做变形，返回有多少个元素

CREATE FUNCTION [ dbo ]. [ GetCount_Split_StrByDelimiter ]( @String VARCHAR( 8000), @Delimiter CHAR( 1))
   RETURNS INT
AS
   BEGIN
    DECLARE @temptable TABLE (items VARCHAR( 8000))
    DECLARE @SplitCount INT
      DECLARE @idx INT
     DECLARE @slice VARCHAR( 8000)

     SELECT @idx = 1
          IF len( @String) < 1 OR @String IS NULL   RETURN   0

       while @idx != 0
        BEGIN
          SET @idx = charindex( @Delimiter, @String)
          IF @idx != 0
              SET @slice = LEFT( @String, @idx - 1)
         ELSE
              SET @slice = @String

          IF( len( @slice) > 0)
             INSERT INTO @temptable(Items) VALUES( @slice)

          SET @String = RIGHT( @String, len( @String) - @idx)
           IF len( @String) = 0 break
      END
      SET   @SplitCount =( SELECT COUNT( *) FROM   @temptable)
    RETURN   @SplitCount
END

示例

SELECT dbo.GetCount_Split_StrByDelimiter( ' sun,star,moon,clouds ', ' , ')

结果返回

SQL: 根据给定的分隔符，分解字符串

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