Question

我正在寻找一个RegExp来查找SQL Server和正则表达式（RegExp）中整个单词中的重复字符。例如：

"AAUGUST"     match (AA)

"ANDREA"      don't match (are 2 vowels "A", buit are separated)

"ELEEPHANT"   match (EE)

我正在尝试：

SELECT field1
FROM exampleTable
WHERE field1 like '%([A-Z]){2}%'

但它不起作用。

我赞成你的帮助。

谢谢！

Answer 1

您不能使用T-SQL LIKE执行您的问题。

你最好的选择是使用Common Language Runtime (CLR)，但也可以使用例如标量值函数来实现（尽管痛苦缓慢）：

create function dbo.ContainsRepeatingAlphaChars(@str nvarchar(max)) returns bit 
as begin
    declare @p int, -- the position we're looking at
            @c char(1) -- the previous char

    if @str is null or len(@str) < 2 return 0;

    select @c = substring(@str, 1, 1), @p = 1;

    while (1=1) begin
        set @p = @p + 1;                 -- move position pointer ahead
        if @p > len(@str) return 0;      -- if we're at the end of the string and haven't already exited, we haven't found a match
        if @c like '[A-Z]' and @c = substring(@str, @p, 1) return 1; -- if last char is A-Z and matches the current char then return "found!"
        set @c = substring(@str, @p, 1); -- Get next char
    end
    return 0; -- this will never be hit but stops SQL Server complaining that not all paths return a value
end
GO

-- Example usage:
SELECT field1
FROM exampleTable
WHERE dbo.ContainsRepeatingAlphaChars(field1) = 1

我提到它会慢吗？不要在大桌子上使用它。去CLR。

T-SQL RegExp用于查找连续重复的字符

1 个答案: