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Join query in MySQL

开发者 https://www.devze.com 2023-01-13 11:25 出处:网络
I have two tables: members and renewals The two tables have a field called memberid which links the two data tables together.I am trying to construct a query which will extract the firstname and surn

I have two tables: members and renewals

The two tables have a field called memberid which links the two data tables together. I am trying to construct a query which will extract the firstname and surname from the members table for the data that is being held in the renewals table. I have tried using the query below which is based on some examples I've looked up.

SELECT members.memberfirst, members.membersurname, members.memberid, renewals.account_name, re开发者_开发知识库newals.memberid 
FROM members, renewals 
WHERE renewals.memberid=members.memberid

The error I get when trying to run this in phpMyAdmin:

#1267 - Illegal mix of collations (utf8_unicode_ci,IMPLICIT) and (utf8_general_ci,IMPLICIT) for operation '='

Join query in MySQL


You should use INNER JOIN. Take a look here: http://www.postgresql.org/docs/8.1/interactive/queries-table-expressions.html
Even if it's for PostgreSQL, the queries are the same for MySQL and the examples are really good.

SELECT members.memberfirst, members.membersurname, members.memberid, renewals.account_name
FROM members
INNER JOIN renewals
ON members.memberid = renewals.memberid

or you can use USING (memberid) instead of ON members.memberid = renewals.memberid


A slight modification if you wanted to display the member's name in a single column

SELECT CONCAT(members.memberfirst, " ", members.membersurname) as memberName, 
members.memberid, renewals.account_name, renewals.memberid 
FROM members
INNER JOIN renewals
WHERE renewals.memberid=members.memberid
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