MySQL Reference

Authentication options and data type handling for MySQL connections.

Server

servers:
  - server: mysql
    type: mysql
    host: localhost
    port: 3306
    database: mydb

Authentication

Variable	Example	Description
DATACONTRACT_MYSQL_USERNAME	root	Username
DATACONTRACT_MYSQL_PASSWORD	mysecretpassword	Password

host, port (default 3306), and database come from the contract's servers block, and can be overridden with DATACONTRACT_MYSQL_HOST, DATACONTRACT_MYSQL_PORT, and DATACONTRACT_MYSQL_DATABASE.

Data types

Importing

datacontract import sql --dialect mysql maps DDL types as follows; the normalized SQL type is kept as physicalType.

MySQL type	logicalType
VARCHAR, CHAR, TEXT	string (maxLength for varchar/char)
INT, INTEGER, BIGINT, SMALLINT	integer
NUMERIC, DECIMAL, FLOAT, DOUBLE	number
BOOLEAN	boolean
DATE	date
TIME	time
DATETIME, TIMESTAMP	timestamp
BLOB, BINARY, VARBINARY	string (format binary)
JSON	object
ENUM(...), YEAR, TINYINT(1), INT UNSIGNED	(unset) — physicalType is still written

Testing

MySQL is reached through DuckDB's MySQL scanner and does not support native type introspection — the declared physicalType is not compared against the catalog. Instead, the logicalType is checked by category (Check that field x has type y), with integer and number treated as compatible.

Logical type mapping

When no physicalType is declared, the CLI derives the native type from the logicalType — for example in datacontract export sql and the dbt exports. This table is generated from the converter in the CLI's code:

logicalType	MySQL type
string	varchar(255)
integer	int
number	decimal
boolean	boolean
date	date
timestamp	timestamp
time	time
object	json
array	json
map	json
vector	vector(1536)