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sql join 2 rows in the same table

开发者 https://www.devze.com 2023-03-17 21:02 出处:网络
I have the following table: NameTypeValue --------------------- mike 开发者_开发问答phone123 mikeaddressnyc

I have the following table:

Name   Type     Value
---------------------
mike 开发者_开发问答  phone    123    
mike   address  nyc    
bob    address  nj    
bob    phone    333

I want to have the result like this:

name  value  value
-------------------
mike  nyc    123
bob   nj     333

How can I do it?


it is called a self-join. the trick is to use aliases.

select 
    address.name,
    address.value as address,
    phone.value as phone
from
    yourtable as address left join
    yourtable as phone on address.name = phone.name
where address.type = 'address' and
      (phone.type is null or phone.type = 'phone')

The query assumes that each name has an address, but phone numbers are optional.


Something like this:

SELECT a.name AS name, phone, address
    FROM (SELECT name, value AS phone FROM mytable WHERE type = "phone") AS a
    JOIN (SELECT name, value AS address FROM mytable WHERE type = "address") AS b
    ON(a.name = b.name);
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