sql-server - 将 PostgreSQL 查询转换为 SQL Server 查询

Question

我需要转换我的查询

select 
    unnest(string_to_array(names, ',')) as "Admin Name",
    unnest(string_to_array(phones, ',')) as "Admin Phone",
    unnest(string_to_array(emails, ',')) as "Admin Emails"
from 
    metadata_Table

到等效的 SQL Server 查询。

有什么建议么？

标签： sql-serverpostgresqltsqlsplitdatabase-migration

Answer 1

您不能在 SL Server 中轻松做到这一点。没有“带有序数的 string_split()”。而且，不保证订购string_split()。

在 Microsoft 增强此功能之前，我的建议是递归子查询：

with cte as (
      select convert(varchar(max), null) as name, convert(varchar(max), null) as phone, convert(varchar(max), null) as email,
             convert(varchar(max), names + ',') as names_rest,
             convert(varchar(max), phones + ',') as phones_rest,
             convert(varchar(max), emails + ',') as emails_rest,
             0 as lev
      from metadata_Table
      union all
      select left(names_rest, charindex(',', names_rest) - 1),
             left(phones_rest, charindex(',', phones_rest) - 1),
             left(emails_rest, charindex(',', emails_rest) - 1),
             stuff(names_rest, 1, charindex(',', names_rest), ''),
             stuff(phones_rest, 1, charindex(',', phones_rest), ''),
             stuff(emails_rest, 1, charindex(',', emails_rest), ''),
             lev + 1
      from cte
      where emails_rest like '%,%'
     )
select *
from cte
where lev > 0;