# yii\db\pgsql

> 7 classes of the yii\db\pgsql namespace.

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

## Classes

| Class | Summary |
| --- | --- |
| [`ArrayExpressionBuilder`](/docs/api/yii/db/pgsql/arrayexpressionbuilder/index.md) | Class ArrayExpressionBuilder builds [`ArrayExpression`](/docs/api/yii/db/arrayexpression/index.md) for PostgreSQL DBMS. |
| [`ArrayParser`](/docs/api/yii/db/pgsql/arrayparser/index.md) | The class converts PostgreSQL array representation to PHP array |
| [`ColumnSchema`](/docs/api/yii/db/pgsql/columnschema/index.md) | Represents the metadata of a column in a PostgreSQL database table. |
| [`JsonExpressionBuilder`](/docs/api/yii/db/pgsql/jsonexpressionbuilder/index.md) | Class JsonExpressionBuilder builds [`JsonExpression`](/docs/api/yii/db/jsonexpression/index.md) for PostgreSQL DBMS. |
| [`QueryBuilder`](/docs/api/yii/db/pgsql/querybuilder/index.md) | QueryBuilder is the query builder for PostgreSQL databases (version 14 and above). |
| [`Schema`](/docs/api/yii/db/pgsql/schema/index.md) | Schema is the class for retrieving metadata from a PostgreSQL database (version 14.0 and above). |
| [`Transaction`](/docs/api/yii/db/pgsql/transaction/index.md) | Represents a PostgreSQL DB transaction. |