sql - 查找大写字符然后添加空格

Question

我买了一个 SQL World City/State 数据库。在状态数据库中，它将状态名称放在一起。示例：“北卡罗来纳”或“南卡罗来纳”...

SQL中有没有办法循环查找大写字符并添加空格？？？

这样“北卡罗来纳”就变成了“北卡罗来纳”？？？

Answer 1

创建这个函数

if object_id('dbo.SpaceBeforeCaps') is not null
    drop function dbo.SpaceBeforeCaps
GO
create function dbo.SpaceBeforeCaps(@s varchar(100)) returns varchar(100)
as
begin
    declare @return varchar(100);
    set @return = left(@s,1);
    declare @i int;
    set @i = 2;
    while @i <= len(@s)
    begin
        if ASCII(substring(@s,@i,1)) between ASCII('A') and ASCII('Z')
            set @return = @return + ' ' + substring(@s,@i,1)
        else
            set @return = @return + substring(@s,@i,1)
        set @i = @i + 1;
    end;
    return @return;
end;
GO

然后你可以用它来更新你的数据库

update tbl set statename = select dbo.SpaceBeforeCaps(statename);

Answer 2

如果您绝对不能创建函数并且需要一次性使用，您可以使用递归 CTE 来分解字符串（并在需要的地方同时添加空格），然后使用 FOR XML 重新组合字符。详细示例如下：

-- some sample data
create table #tmp (id int identity primary key, statename varchar(100));
insert #tmp select 'NorthCarolina';
insert #tmp select 'SouthCarolina';
insert #tmp select 'NewSouthWales';

-- the complex query updating the "statename" column in the "#tmp" table
;with cte(id,seq,char,rest) as (
    select id,1,cast(left(statename,1) as varchar(2)), stuff(statename,1,1,'')
      from #tmp
     union all
    select id,seq+1,case when ascii(left(rest,1)) between ascii('A') and ascii('Z')
                         then ' ' else '' end + left(rest,1)
         , stuff(rest,1,1,'')
      from cte
     where rest > ''
), recombined as (
  select a.id, (select b.char+''
                  from cte b
                 where a.id = b.id
              order by b.seq
                   for xml path, type).value('/','varchar(100)') fixed
    from cte a
group by a.id
)
update t
   set statename = c.fixed
  from #tmp t
  join recombined c on c.id = t.id
 where statename != c.fixed;

-- check the result
select * from #tmp

----------- -----------
id          statename
----------- -----------
1           North Carolina
2           South Carolina
3           New South Wales

Answer 3

有几种方法可以解决这个问题

1. 使用模式和PATINDEX特征构造函数。

2. 为每种情况链接最小的REPLACE语句（例如REPLACE(state_name, 'hC', 'h C' for your example case)。这似乎是一种 hack，但实际上可能会给你最好的性能，因为你有这么小的一组替换。