dbt-mysql

This plugin ports dbt functionality to MySQL and MariaDB.

This is an experimental plugin:

We have not tested it extensively
Storage engines other than the default of InnoDB are untested
Only tested with dbt-tests-adapter with the following:
- MySQL 5.7
- MySQL 8.0
- MariaDB 10.5
Compatiblity with other dbt packages (like dbt_utils) is also untested
Supported Python Versions are: 3.6, 3.7, 3.8 & 3.9

Please read these docs carefully and use at your own risk. Issues and PRs welcome!

Installation
Supported features
- MySQL 5.7 configuration gotchas
Configuring your profile
Notes
Running Tests
Reporting bugs and contributing code

Installation

This plugin can be installed via pip:

$ python -m pip install dbt-mysql

Supported features

MariaDB 10.5	MySQL 5.7	MySQL 8.0	Feature
✅	✅	✅	Table materialization
✅	✅	✅	View materialization
✅	✅	✅	Incremental materialization
✅	❌	✅	Ephemeral materialization
✅	✅	✅	Seeds
✅	✅	✅	Sources
✅	✅	✅	Custom data tests
✅	✅	✅	Docs generate
🤷	🤷	✅	Snapshots

Notes:

Ephemeral materializations rely upon Common Table Expressions (CTEs), which are not supported until MySQL 8.0
MySQL 5.7 has some configuration gotchas that affect snapshots (see below).

MySQL 5.7 configuration gotchas

dbt snapshots might not work properly due to automatic initialization and updating for TIMESTAMP if:

the output of SHOW VARIABLES LIKE 'sql_mode' includes NO_ZERO_DATE

A solution is to include the following in a *.cnf file:

[mysqld]
explicit_defaults_for_timestamp = true
sql_mode = "ALLOW_INVALID_DATES,{other_sql_modes}"

where {other_sql_modes} is the rest of the modes from the SHOW VARIABLES LIKE 'sql_mode' output.

Configuring your profile

A dbt profile can be configured to run against MySQL using configuration example below.

Use type: mysql for MySQL 8.x, type: mysql5 for MySQL 5.x, and type: mariadb for MariaDB.

Example entry for profiles.yml:

your_profile_name:
  target: dev
  outputs:
    dev:
      type: mysql
      server: localhost
      port: 3306
      schema: analytics
      username: your_mysql_username
      password: your_mysql_password
      ssl_disabled: True

Option	Description	Required?	Example
type	The specific adapter to use	Required	`mysql`, `mysql5` or `mariadb`
server	The server (hostname) to connect to	Required	`yourorg.mysqlhost.com`
port	The port to use	Optional	`3306`
schema	Specify the schema (database) to build models into	Required	`analytics`
username	The username to use to connect to the server	Required	`dbt_admin`
password	The password to use for authenticating to the server	Required	`correct-horse-battery-staple`
ssl_disabled	Set to enable or disable TLS connectivity to mysql5.x	Optional	`True` or `False`

Notes

Conflicting terminology is used between:

dbt
Database management systems (DBMS) like MySQL, Postgres, and Snowflake
metadata in the ANSI-standard information_schema

The conflicts include both:

the same word meaning different things
different words meaning the same thing

For example, a "database" in MySQL is not the same as a "database" in dbt, but it is equivalent to a "schema" in Postgres 🤯.

dbt-mysql uses the dbt terms. The native MySQL verbiage is restricted to SQL statements.

This cross-walk aligns the terminology:

information_schema	dbt (and Postgres)	MySQL
catalog	database	undefined / not implemented
schema	schema	database
relation (table/view)	relation (table/view)	relation (table/view)
column	column	column

Additionally, many DBMS have relation names with three parts whereas MySQL has only two. E.g., a fully-qualified table name in Postgres is database.schema.table versus database.table in MySQL. The missing part in MySQL is the information_schema "catalog".

DBMS	Fully-qualified relation name	Parts
Postgres	`database.schema.table`	3
MySQL	`database.table`	2

Running Tests

See test/README.md for details on running the integration tests.

Reporting bugs and contributing code

Want to report a bug or request a feature? See the contributing guidelines, or open an issue.

Credits

dbt-mysql borrows from dbt-spark and dbt-sqlite since Spark and SQLite also use two-part relation names.

lpezet/dbt-mysql