Question

是否存在SQL查询来将字符串中的偶数字符替换为大写，其余字符替换为小写？

例如，如果字符串为“ sagar”，则结果应类似于

button

什么是合适的解决方案？

Answer 1

我无法抗拒回答。对于递归CTE来说，这似乎是很自然的：

with t as (
      select 'abcdef' as str
     ),
     cte as (
      select cast(lower(str) as varchar(max)) as str, 1 as pos
      from t
      union all
      select stuff(str, pos + 1, 1,
                   (case when pos % 2 = 1 then upper(substring(str, pos + 1, 1))
                         else lower(substring(str, pos + 1, 1))
                    end)
                   ) as str, 1 + pos
      from cte
      where pos < len(str)
     )
select top (1) *
from cte
order by pos desc;

Answer 2

编写下面的代码，效果很好

在主数据库上测试

declare @name nvarchar(50)
declare @i int
set @i=1
set @name='sagar'
while(@i<=LEN(@name))
begin
if(@i%2=0)
    begin
        print Upper(SUBSTRING(@name,@i,1))
        set @i=@i+1
    end
else
    begin
        print Lower(SUBSTRING(@name,@i,1))
        set @i=@i+1
    end
end

在设置@name参数时给出自己选择的名称，即可获得所需的结果

Answer 3

使用统计表...

declare @table table ([name] varchar(64))
insert into @table
values 
('sAgAr')
,('abcdefghijk')
,('LMNOPQ')

;WITH
    E1(N) AS (select 1 from (values (1),(1),(1),(1),(1),(1),(1),(1),(1),(1))dt(n)),
    E2(N) AS (SELECT 1 FROM E1 a, E1 b), --10E+2 or 100 rows
    E4(N) AS (SELECT 1 FROM E2 a, E2 b), --10E+4 or 10,000 rows max
    cteTally(N) AS 
    (
        SELECT  ROW_NUMBER() OVER (ORDER BY (SELECT NULL)) FROM E4
    )


select 
    t.[name]
    ,lower(left(t.[name],1))
     + 
     STUFF((
        SELECT '' + case 
                        when c2.N%2 = 0 then upper(substring(t2.[name],c2.N,1)) 
                        else lower(substring(t2.[name],c2.N,1)) 
                    end
        FROM @table t2
        cross apply cteTally c2
        where 
            len(t2.[name]) >= c2.N
            and t2.name = t.name
        FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 1, '')
from
    @table t

Answer 4

这是通过分成几行然后再次创建字符串来完成的：

declare @test table ([value] nvarchar(20))
insert into @test values ('sagar'), ('Blueprint'), ('turtLe')

;with cte as (
    select [value]
        , num
        , iif(num % 2 = 0, upper(substring([value], num, 1)), lower(substring([value], num, 1))) as [char]
    from @test
    cross join (values (1), (2), (3), (4), (5), (6), (7), (8), (9), (10), (11), (12)) numbers(num) --add more for > 12 characters
    where num <= len([Value]))
select distinct [Value], [CaseApplied] = STUFF(( SELECT '' + [char]
                FROM    cte AS c
                WHERE c.[value]= cte.value
                FOR XML PATH('')
                ), 1, 0, '')
from cte

Answer 5

这是一种方法：

DECLARE @mystringLOW varchar(100) = 'sagar'
       ,@pos int = 2

WHILE @pos <= LEN(@mystringLOW)
BEGIN
SET @mystringLOW = (SELECT STUFF(@mystringLOW, @pos, 1, UPPER(SUBSTRING(@mystringLOW, @pos, 1))))
SET @pos += 2
END

SELECT @mystringLOW AS [my answer]

产生：

my answer
---------
sAgAr

将偶数字符替换为大写，其余字符替换为小写

5 个答案: