T SQL条件字符串连接

Question

有5列地址数据.我需要将这些字段连接成一个地址,如果它们存在,则在值之间有空格.如果列具有空值,我应该跳过它而不输入任何空格.

select 
        case 
            when street_number != '' THEN (cast(street_number as int)) 
        end as street_number,
        case
            when street_ext != '' then
                    case
                        when street_ext = 50 then '1/2'
                    end
        end as street_ext,
        case
            when street_direct ! = '' then street_direct
        end as street_direct,
        case
            when site_street ! = '' then site_street
        end as site_street,
        case
            when site_address ! = '' then site_address
        end as site_address
    from parcel 

我想要做的是有一个变量,并将其分配给第一列street_number的值,然后当我移动到下一列,street_ext,如果它不为null我想检查是否变量为null,如果没有,则追加一个空格和值...等等.

我生气了,可以用正确的方向推动.

感谢大家.

Answer 1

使用"+"连接TSQL中的字符串:

SELECT CASE 
         WHEN LEN(p.street_number) > 0 THEN p.street_number + ' ' 
         ELSE '' 
       END +
       CASE 
         WHEN p.street_ext = 50 THEN '1/2'
         WHEN LEN(p.street_ext) > 0 THEN ''
         ELSE p.street_ext
       END + ' ' +
       CASE 
         WHEN LEN(p.street_direct) > 0 THEN p.street_direct + ' '
         ELSE ''
       END + 
       CASE 
         WHEN LEN(p.site_street) > 0 THEN p.site_street + ' '
         ELSE ''
       END  + 
       CASE 
         WHEN LEN(p.site_address) > 0 THEN p.site_address + ' '
         ELSE ''
       END AS full_address
FROM PARCEL p

该LEN函数返回零如果字符串值是NULL,或一个零长度的字符串.

Answer 2

嵌套的isnulls可以做你需要的.就像是:

SELECT
     ISNULL(streetnumber + ' ', '')
       + ISNULL(streetext + ' ', '')
       etc

依赖于NULL +''= NULL的事实.

Answer 3

类似的东西：

select coalesce(street_number+' ','')+
       coalesce(case when street_ext=50 then '1/2' else null end+' ','')+
       coalesce(street_direct+' ','')+
       coalesce(site_street+' ','')+
       coalesce(site_address,'')
from parcel