Is it possible to write join query between multiple databases across different servers?
Is it possible?
The answer to your question is, Yes it is possible.
But since you have not specified any particular situation you are facing,it is not possible to give a direct answer.
In MySQL it can be done using The FEDERATED Storage Engine.
However I suggest you go through following SO questions
Join tables from two different server
Joining tables across multiple servers
MySQL Cross Server Select Query
MySQL — join between tables in 2 different databases?
How To Left Join 2 Tables On 2 Different Databases?
Connecting multiple database and join query across database in php
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I tried this query below and got a database query builder not converted to string error
ModelA::join(DB::connection('mysql2')->table('table1'), 'modela.id','table1.id')->get();
Eloquent does not support joining data from different connections.
If both databases are stored on different servers, the only thing you can do is to fetch relevant data from both connections and then join it programatically.
Joining data from different databases is possible if both databases are stored on the same server. In order to do that, you'll need to prefix table names with database names. With Eloquent, you'd additionally need to use the same connection to access both databases.
Then, it could look like this:
ModelA::join('database2.table1', 'modela.id', 'database2.table1.id')->get()
Sorry, but I'm quite newbie in SQL and PHP. Previously, I was able to easily join 2 tables columns in PHPmyadmin with the design button with out any PHP. However, I'm trying to retrieve my database with python, so I have to MYSQL workbench.
I'm trying join 2 columns on seperate tables, but I can't get it to work. Firstly, I've watched several tutorials and I really can't understand PHP and all the scripting. Secondly, I tried joining the 2 tables when in reverse engineer since it seems quite similar to PHPmyadmin, however I cannot select individual columns while in reverse engineer, even if I try to index the columns.
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I'm trying to join or make class1, class2, class3 from student table equal to classid from the class table. Is it possible at all to join the 2 tables here so it would actually show a linking between 2 specific columns? I can easily add a line but it always selects the primary key.
I appreciate any help, thanks. Alternatively, if I could get help in developing a PHP script, which also shows the linking between 2 tables, that'd also be great.
I have multiple databases and I need to search for a value in a table and set it to NULL in all instances across all databases.
I know how to query individual databases after "USE 'DBName'" is called to select a particular database.
How do I loop all databases?
Use the SHOW DATABASES query to list all databases.
You don't need to USE the database to query its tables:
SELECT something FROM databasename.sometable
I'm intending to develope a web that interacts with three different Mysql databases in the same server. User and password are the same in all three databases.
I want to use mysqli in procedural mode.
Some times I want to query just one databse, some times two of them, whatever.
What would it be the best way to connect with two of them and then, say, join two tables belonging to different databases?
Thanks in advanced!
If the databases all reside in the same server, you can query any table in any database at any time that you have access to by prefixing it with the database name:
SELECT *
FROM database1.table1
JOIN database2.table2 ON ...
If the databases are on two different servers or need different access rights, there's no way to do this.
I have one table t1 on database d1 of the server s1 and now another table t2 is in d2 of the server s2.Now i want some data of the table t1 and its related data from t2 table as resultant data.how can i make it possible?
FEDERATED Storage Engine in MySQL 5.0.related document i have seen any other option...what can i do to get data across two different server?
There are two solutions to your problem:
1). MySQL based using Federated Engine (as mentioned by you). You can go through this Blog post on Federated Engine
2). (As you are using PHP) Fetching data from one server, then either looping through the data and firing relevant queries to another server, or firing single aggregated query to another server based on the data fetched from first server.
Hope it will help you...