# MySQL Reference

> All MySQL authentication options and data type mappings.

#  MySQL Reference

Authentication options and data type handling for [MySQL connections](../connect/mysql.md).

## 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.

## 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.

{/* AUTOGENERATED TYPE MAPPING: do not edit by hand; regenerate with update_reference_types.py */}

### 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` |

{/* END AUTOGENERATED TYPE MAPPING */}