Version Controlled Database

Dolt is a MySQL compatible database server.
Starting a server
To start a server you run dolt sql-server. This starts a server standard MySQL clients can connect to on port 3306. Databases created by the server process are by default stored in the directory where dolt sql-server was run.
Connect to the running server
The Dolt server will talk to any tool that can connect to MySQL. Dolt ships with a built-in shell, or you can use the standard mysql command line client, or a GUI of your choice.
dolt sql-client
dolt sql-client will start a SQL shell that finds the server running on port 3306 and connects to it.
mysql client
Download the mysql shell if you don't have it. On Linux use:
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sudo apt-get install mysql-shell
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Then connect. On Mac and Linux you will need to use the localhost IP address to force a TCP connection (rather than using a socket).
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% mysql --host 127.0.0.1 --port 3306 -uroot
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Running SQL
Any standard SQL statement that works in MySQL works in Dolt.
For version control features, Dolt implements Git read operations as system tables and Git write operations as SQL functions. Follow along below for a quick tutorial.
Create a database
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create database dolts;
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Create a table
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use dolts;
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create table employees (
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    last_name varchar(255), 
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    first_name varchar(255), 
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    title varchar(255), 
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    date_started date, 
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    primary key(last_name, first_name)
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);
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Any SQL type supported by MySQL works in Dolt as well.
Create a Dolt commit
To create a commit, use the dolt_commit function. This is equivalent to running dolt commit on the command line, and accepts the same arguments. All dolt commands work the same as their git equivalents.
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select dolt_commit('-a', '-m', 'Created employees table');
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Note, -a was used to commit all modified tables in the working set.
Insert data
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insert into employees values ('Sehn', 'Tim', 'CEO', '2018-08-06');
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select dolt_commit('-a', '-m', 'Inserted Tim Sehn, CEO');
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Create a branch and insert data on it
To create a branch, use the dolt_checkout function. This is equivalent to running dolt checkout on the command line, and accepts the same arguments.
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select dolt_checkout('-b', 'founders');
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insert into employees values ('Son', 'Aaron', 'Founder', '2018-08-06');
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insert into employees values ('Hendriks', 'Brian', 'Founder', '2018-08-06');
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View the diff
On the command line, we would run dolt diff, which works the same as git diff. From a SQL session, we select from the dolt_diff system table. Each table in the database has a corresponding dolt_diff table. The employees table we created above has a dolt_diff_employees table.
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dolts> select * from dolt_diff_employees where to_commit = 'WORKING';
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+-------------------------------+--------------+----------+---------------+-----------+----------------+-------------------+----------------+------------+-----------------+----------------------------------+-----------------------------------+-----------+
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| to_date_started               | to_last_name | to_title | to_first_name | to_commit | to_commit_date | from_date_started | from_last_name | from_title | from_first_name | from_commit                      | from_commit_date                  | diff_type |
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+-------------------------------+--------------+----------+---------------+-----------+----------------+-------------------+----------------+------------+-----------------+----------------------------------+-----------------------------------+-----------+
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| 2018-08-06 00:00:00 +0000 UTC | Hendriks     | Founder  | Brian         | WORKING   | NULL           | NULL              | NULL           | NULL       | NULL            | fv4s0mathd64slfb2jb22dqugbqrdmtb | 2021-12-07 01:00:31.821 +0000 UTC | added     |
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| 2018-08-06 00:00:00 +0000 UTC | Son          | Founder  | Aaron         | WORKING   | NULL           | NULL              | NULL           | NULL       | NULL            | fv4s0mathd64slfb2jb22dqugbqrdmtb | 2021-12-07 01:00:31.821 +0000 UTC | added     |
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+-------------------------------+--------------+----------+---------------+-----------+----------------+-------------------+----------------+------------+-----------------+----------------------------------+-----------------------------------+-----------+
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Merge the branch back to main
To merge a branch, use the dolt_merge function. This is equivalent to running dolt checkout on the command line, and accepts the same arguments. Only commits can be merged, so make sure to commit everything in the working set before merging.
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select dolt_commit('-a', '-m', 'Added founders');
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select dolt_checkout('main');
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select dolt_merge('founders');
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Inspect the log
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select * from dolt_log;
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+----------------------------------+---------------+------------------+-----------------------------------+----------------------------+
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| commit_hash                      | committer     | email            | date                              | message
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      |
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+----------------------------------+---------------+------------------+-----------------------------------+----------------------------+
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| m9gr4bdjkdctn66lbv75guju59g65me4 | Zach Musgrave | zach@dolthub.com | 2021-12-06 17:07:12.548 -0800 PST | Added founders             |
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| fv4s0mathd64slfb2jb22dqugbqrdmtb | Zach Musgrave | zach@dolthub.com | 2021-12-06 17:00:31.821 -0800 PST | Inserted Tim Sehn, CEO     |
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| q66dpld8ai67jo6pv0q2mirensqucf1b | Zach Musgrave | zach@dolthub.com | 2021-12-06 16:56:49.546 -0800 PST | Initialize data repository |
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+----------------------------------+---------------+------------------+-----------------------------------+----------------------------+
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Next Steps
As you can see, Dolt is a fully compatible MySQL server with additional Git-style version control functionality implemented as system tables and SQL functions. You can use Dolt in this mode to back applications and give those applications version control at the data layer.
Keep reading the getting started guide to learn more, or jump straight to advanced SQL topics:
​Dolt SQL functions​
​Dolt system tables​
​Using branches​