# yii\db\mysql

> 5 classes of the yii\db\mysql namespace.

[API reference](/docs/api/index.md) › [yii](/docs/api/yii/index.md) › [db](/docs/api/yii/db/index.md) › mysql

## Classes

| Class | Summary |
| --- | --- |
| [`ColumnSchema`](/docs/api/yii/db/mysql/columnschema/index.md) | Represents the metadata of a column in a MySQL database table. |
| [`ColumnSchemaBuilder`](/docs/api/yii/db/mysql/columnschemabuilder/index.md) | ColumnSchemaBuilder is the schema builder for MySQL databases. |
| [`JsonExpressionBuilder`](/docs/api/yii/db/mysql/jsonexpressionbuilder/index.md) | Class JsonExpressionBuilder builds [`JsonExpression`](/docs/api/yii/db/jsonexpression/index.md) for MySQL DBMS. |
| [`QueryBuilder`](/docs/api/yii/db/mysql/querybuilder/index.md) | QueryBuilder is the query builder for MySQL databases (MySQL 8.0+ and MariaDB 10.6+). |
| [`Schema`](/docs/api/yii/db/mysql/schema/index.md) | Schema is the class for retrieving metadata from a MySQL database (version 8.0 and later). |