mysql-server

This is an experimental implementation of a MergeStat backend for go-mysql-server from DoltHub. The go-mysql-server is a "frontend" SQL engine based on a MySQL syntax and wire protocol implementation. It allows for pluggable "backends" as database and table providers.

Database

When you connect with a MySQL client, the database name you specify will be a reference to a git repository. Currently, this can either be an HTTP(s) URL (https://github.com/mergestat/mergestat) or a path to a repository on disk.

For instance, the following will list all commits from mergestat/mergestat. The repo is cloned to a temporary directory in the container before the query is executed.

mysql --host=127.0.0.1 --port=3306 "https://github.com/mergestat/mergestat" -u root -proot -e "select * from commits"

Example

You can use a MySQL client to connect to the server and execute queries. For instance, the following is a query against the React codebase that produces a chart of unique contributors every month (by author_email), using Arctype:

SELECT
    count(DISTINCT author_email),
    YEAR(author_when) AS y,
    MONTH(author_when) AS m,
    DATE_FORMAT(author_when, '%Y-%m')
FROM commits
WHERE parents < 2
GROUP BY y, m
ORDER BY y, m

Tables

• commits
• refs
• files
• stats

Usage

The easiest way to get started (for now) is probably by building and running a Docker container locally. MergeStat has some build dependencies (such as libgit2), which must be available on your system when compiling (see the Makefile for details).

You can use the included docker-compose.yaml file in this repository by running docker compose up. This will start a MySQL server on port 3306.

You may also run docker build . -t mergestat/mysql-server to produce a docker image you can run like so:

docker run -p 3306:3306 -v ${PWD}:/repo mergestat/mysql-server

Note the -v flag, in the above we're mounting the current directory (assumed to be a git repo) into /repo in the container.

The repo path is specified by the database name used when connecting to the MySQL server. So, in the above, you would connect like so:

mysql --host=127.0.0.1 --port=3306 "/repo" -u root -proot -e "select hash from commits"

Note the password defaults to root. The user/password can be set by supplying the MYSQL_USER and MYSQL_PWD env vars.

TODO

• Publish pre-built binaries
• Publish a Docker image