# QueryBuilder

> QueryBuilder is the query builder for PostgreSQL databases (version 14 and above).

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

| class | `yii\db\pgsql\QueryBuilder` |
| --- | --- |
| Extends | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) » [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| Implements | [`yii\base\Configurable`](/docs/api/yii/base/configurable/index.md) |
| Since | 2.0 |
| Source | [`framework/db/pgsql/QueryBuilder.php`](https://github.com/yiisoft/yii2/blob/22.0/framework/db/pgsql/QueryBuilder.php#L44) |

QueryBuilder is the query builder for PostgreSQL databases (version 14 and above).

## Properties

| Property | Type | Description | Defined by |
| --- | --- | --- | --- |
| <span id="property-db"></span>[`$db`](/docs/api/yii/db/querybuilder/index.md#property-db) | [`yii\db\Connection`](/docs/api/yii/db/connection/index.md) | The database connection. Default: `null`. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="property-separator"></span>[`$separator`](/docs/api/yii/db/querybuilder/index.md#property-separator) | `string` | The separator between different fragments of a SQL statement. Default: `' '`. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="property-typeMap"></span>`$typeMap` | `array` | Mapping from abstract column types (keys) to physical column types (values). Default: `[\yii\db\pgsql\Schema::TYPE_PK => 'serial NOT NULL PRIMARY KEY', \yii\db\pgsql\Schema::TYPE_UPK => 'serial NOT NULL PRIMARY KEY', \yii\db\pgsql\Schema::TYPE_BIGPK => 'bigserial NOT NULL PRIMARY KEY', \yii\db\pgsql\Schema::TYPE_UBIGPK => 'bigserial NOT NULL PRIMARY KEY', \yii\db\pgsql\Schema::TYPE_CHAR => 'char(1)', \yii\db\pgsql\Schema::TYPE_STRING => 'varchar(255)', \yii\db\pgsql\Schema::TYPE_TEXT => 'text', \yii\db\pgsql\Schema::TYPE_TINYINT => 'smallint', \yii\db\pgsql\Schema::TYPE_SMALLINT => 'smallint', \yii\db\pgsql\Schema::TYPE_INTEGER => 'integer', \yii\db\pgsql\Schema::TYPE_BIGINT => 'bigint', \yii\db\pgsql\Schema::TYPE_FLOAT => 'double precision', \yii\db\pgsql\Schema::TYPE_DOUBLE => 'double precision', \yii\db\pgsql\Schema::TYPE_DECIMAL => 'numeric(10,0)', \yii\db\pgsql\Schema::TYPE_DATETIME => 'timestamp(0)', \yii\db\pgsql\Schema::TYPE_TIMESTAMP => 'timestamp(0)', \yii\db\pgsql\Schema::TYPE_TIME => 'time(0)', \yii\db\pgsql\Schema::TYPE_DATE => 'date', \yii\db\pgsql\Schema::TYPE_BINARY => 'bytea', \yii\db\pgsql\Schema::TYPE_BOOLEAN => 'boolean', \yii\db\pgsql\Schema::TYPE_MONEY => 'numeric(19,4)', \yii\db\pgsql\Schema::TYPE_JSON => 'jsonb']`. | `QueryBuilder` |
| <span id="property-conditionClasses"></span>[`$conditionClasses`](/docs/api/yii/db/querybuilder/index.md#property-conditionClasses) protected | `array` | Map of condition aliases to condition classes. Default: `[]`. Available since 2.0.14. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="property-expressionBuilders"></span>[`$expressionBuilders`](/docs/api/yii/db/querybuilder/index.md#property-expressionBuilders) protected | `string[]\|`[`yii\db\ExpressionBuilderInterface`](/docs/api/yii/db/expressionbuilderinterface/index.md)`[]` | Maps expression class to expression builder class. Default: `[]`. Available since 2.0.14. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |

## Methods

| Method | Description | Defined by |
| --- | --- | --- |
| <span id="method-__construct"></span>[`__construct()`](/docs/api/yii/db/querybuilder/index.md#method-__construct) | Constructor. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-__call"></span>[`__call()`](/docs/api/yii/base/baseobject/index.md#method-__call) | Calls the named method which is not a class method. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-__get"></span>[`__get()`](/docs/api/yii/base/baseobject/index.md#method-__get) | Returns the value of an object property. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-__isset"></span>[`__isset()`](/docs/api/yii/base/baseobject/index.md#method-__isset) | Checks if a property is set, i.e. defined and not null. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-__set"></span>[`__set()`](/docs/api/yii/base/baseobject/index.md#method-__set) | Sets value of an object property. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-__unset"></span>[`__unset()`](/docs/api/yii/base/baseobject/index.md#method-__unset) | Sets an object property to null. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-addCheck"></span>[`addCheck()`](/docs/api/yii/db/querybuilder/index.md#method-addCheck) | Creates a SQL command for adding a check constraint to an existing table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-addColumn"></span>[`addColumn()`](/docs/api/yii/db/querybuilder/index.md#method-addColumn) | Builds a SQL statement for adding a new DB column. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-addCommentOnColumn"></span>[`addCommentOnColumn()`](/docs/api/yii/db/querybuilder/index.md#method-addCommentOnColumn) | Builds a SQL command for adding comment to column. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-addCommentOnTable"></span>[`addCommentOnTable()`](/docs/api/yii/db/querybuilder/index.md#method-addCommentOnTable) | Builds a SQL command for adding comment to table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-addDefaultValue"></span>[`addDefaultValue()`](/docs/api/yii/db/querybuilder/index.md#method-addDefaultValue) | Creates a SQL command for adding a default value constraint to an existing table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-addForeignKey"></span>[`addForeignKey()`](/docs/api/yii/db/querybuilder/index.md#method-addForeignKey) | Builds a SQL statement for adding a foreign key constraint to an existing table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-addPrimaryKey"></span>[`addPrimaryKey()`](/docs/api/yii/db/querybuilder/index.md#method-addPrimaryKey) | Builds a SQL statement for adding a primary key constraint to an existing table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-addUnique"></span>[`addUnique()`](/docs/api/yii/db/querybuilder/index.md#method-addUnique) | Creates a SQL command for adding an unique constraint to an existing table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`alterColumn()`](#method-alterColumn) | Builds a SQL statement for changing the definition of a column. | `QueryBuilder` |
| [`batchInsert()`](#method-batchInsert) | Generates a batch INSERT SQL statement. | `QueryBuilder` |
| <span id="method-bindParam"></span>[`bindParam()`](/docs/api/yii/db/querybuilder/index.md#method-bindParam) | Helper method to add $value to $params array using [`PARAM_PREFIX`](/docs/api/yii/db/querybuilder/index.md#const-PARAM_PREFIX). | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-build"></span>[`build()`](/docs/api/yii/db/querybuilder/index.md#method-build) | Generates a SELECT SQL statement from a [`Query`](/docs/api/yii/db/query/index.md) object. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildColumns"></span>[`buildColumns()`](/docs/api/yii/db/querybuilder/index.md#method-buildColumns) | Processes columns and properly quotes them if necessary. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildCondition"></span>[`buildCondition()`](/docs/api/yii/db/querybuilder/index.md#method-buildCondition) | Parses the condition specification and generates the corresponding SQL expression. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildExpression"></span>[`buildExpression()`](/docs/api/yii/db/querybuilder/index.md#method-buildExpression) | Builds given $expression | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildFrom"></span>[`buildFrom()`](/docs/api/yii/db/querybuilder/index.md#method-buildFrom) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildGroupBy"></span>[`buildGroupBy()`](/docs/api/yii/db/querybuilder/index.md#method-buildGroupBy) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildHaving"></span>[`buildHaving()`](/docs/api/yii/db/querybuilder/index.md#method-buildHaving) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildJoin"></span>[`buildJoin()`](/docs/api/yii/db/querybuilder/index.md#method-buildJoin) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`buildLimit()`](#method-buildLimit) | Builds the LIMIT and OFFSET clauses for a SELECT query using the PostgreSQL `OFFSET ... FETCH` syntax. | `QueryBuilder` |
| <span id="method-buildOrderBy"></span>[`buildOrderBy()`](/docs/api/yii/db/querybuilder/index.md#method-buildOrderBy) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildOrderByAndLimit"></span>[`buildOrderByAndLimit()`](/docs/api/yii/db/querybuilder/index.md#method-buildOrderByAndLimit) | Builds the ORDER BY and LIMIT/OFFSET clauses and appends them to the given SQL. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildSelect"></span>[`buildSelect()`](/docs/api/yii/db/querybuilder/index.md#method-buildSelect) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildUnion"></span>[`buildUnion()`](/docs/api/yii/db/querybuilder/index.md#method-buildUnion) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildUnionOrderByAndLimit"></span>[`buildUnionOrderByAndLimit()`](/docs/api/yii/db/querybuilder/index.md#method-buildUnionOrderByAndLimit) | Builds the global ORDER BY and LIMIT/OFFSET clauses for a UNION query. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildWhere"></span>[`buildWhere()`](/docs/api/yii/db/querybuilder/index.md#method-buildWhere) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-buildWithQueries"></span>[`buildWithQueries()`](/docs/api/yii/db/querybuilder/index.md#method-buildWithQueries) |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-canGetProperty"></span>[`canGetProperty()`](/docs/api/yii/base/baseobject/index.md#method-canGetProperty) | Returns a value indicating whether a property can be read. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-canSetProperty"></span>[`canSetProperty()`](/docs/api/yii/base/baseobject/index.md#method-canSetProperty) | Returns a value indicating whether a property can be set. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| [`checkIntegrity()`](#method-checkIntegrity) | Builds a SQL statement for enabling or disabling integrity checks. | `QueryBuilder` |
| <span id="method-className"></span>[`className()`](/docs/api/yii/base/baseobject/index.md#method-className) static | Returns the fully qualified name of this class. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-createConditionFromArray"></span>[`createConditionFromArray()`](/docs/api/yii/db/querybuilder/index.md#method-createConditionFromArray) | Transforms $condition defined in array format (as described in [`Query::where()`](/docs/api/yii/db/query/index.md#method-where) to instance of ConditionInterface according to [`$conditionClasses`](/docs/api/yii/db/querybuilder/index.md#property-conditionClasses) map. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`createIndex()`](#method-createIndex) | Builds a SQL statement for creating a new index. | `QueryBuilder` |
| <span id="method-createTable"></span>[`createTable()`](/docs/api/yii/db/querybuilder/index.md#method-createTable) | Builds a SQL statement for creating a new DB table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-createView"></span>[`createView()`](/docs/api/yii/db/querybuilder/index.md#method-createView) | Creates a SQL View. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-delete"></span>[`delete()`](/docs/api/yii/db/querybuilder/index.md#method-delete) | Creates a DELETE SQL statement. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropCheck"></span>[`dropCheck()`](/docs/api/yii/db/querybuilder/index.md#method-dropCheck) | Creates a SQL command for dropping a check constraint. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropColumn"></span>[`dropColumn()`](/docs/api/yii/db/querybuilder/index.md#method-dropColumn) | Builds a SQL statement for dropping a DB column. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropCommentFromColumn"></span>[`dropCommentFromColumn()`](/docs/api/yii/db/querybuilder/index.md#method-dropCommentFromColumn) | Builds a SQL command for adding comment to column. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropCommentFromTable"></span>[`dropCommentFromTable()`](/docs/api/yii/db/querybuilder/index.md#method-dropCommentFromTable) | Builds a SQL command for adding comment to table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropDefaultValue"></span>[`dropDefaultValue()`](/docs/api/yii/db/querybuilder/index.md#method-dropDefaultValue) | Creates a SQL command for dropping a default value constraint. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropForeignKey"></span>[`dropForeignKey()`](/docs/api/yii/db/querybuilder/index.md#method-dropForeignKey) | Builds a SQL statement for dropping a foreign key constraint. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`dropIndex()`](#method-dropIndex) | Builds a SQL statement for dropping an index. | `QueryBuilder` |
| <span id="method-dropPrimaryKey"></span>[`dropPrimaryKey()`](/docs/api/yii/db/querybuilder/index.md#method-dropPrimaryKey) | Builds a SQL statement for removing a primary key constraint to an existing table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropTable"></span>[`dropTable()`](/docs/api/yii/db/querybuilder/index.md#method-dropTable) | Builds a SQL statement for dropping a DB table. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropUnique"></span>[`dropUnique()`](/docs/api/yii/db/querybuilder/index.md#method-dropUnique) | Creates a SQL command for dropping an unique constraint. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-dropView"></span>[`dropView()`](/docs/api/yii/db/querybuilder/index.md#method-dropView) | Drops a SQL View. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-executeResetSequence"></span>[`executeResetSequence()`](/docs/api/yii/db/querybuilder/index.md#method-executeResetSequence) | Execute a SQL statement for resetting the sequence value of a table's primary key. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-getColumnType"></span>[`getColumnType()`](/docs/api/yii/db/querybuilder/index.md#method-getColumnType) | Converts an abstract column type into a physical column type. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-getExpressionBuilder"></span>[`getExpressionBuilder()`](/docs/api/yii/db/querybuilder/index.md#method-getExpressionBuilder) | Gets object of [`ExpressionBuilderInterface`](/docs/api/yii/db/expressionbuilderinterface/index.md) that is suitable for $expression. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-hasMethod"></span>[`hasMethod()`](/docs/api/yii/base/baseobject/index.md#method-hasMethod) | Returns a value indicating whether a method is defined. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-hasProperty"></span>[`hasProperty()`](/docs/api/yii/base/baseobject/index.md#method-hasProperty) | Returns a value indicating whether a property is defined. | [`yii\base\BaseObject`](/docs/api/yii/base/baseobject/index.md) |
| <span id="method-init"></span>[`init()`](/docs/api/yii/db/querybuilder/index.md#method-init) | Initializes the object. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`insert()`](#method-insert) | Creates an INSERT SQL statement. | `QueryBuilder` |
| <span id="method-renameColumn"></span>[`renameColumn()`](/docs/api/yii/db/querybuilder/index.md#method-renameColumn) | Builds a SQL statement for renaming a column. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`renameTable()`](#method-renameTable) | Builds a SQL statement for renaming a DB table. | `QueryBuilder` |
| [`resetSequence()`](#method-resetSequence) | Creates a SQL statement for resetting the sequence value of a table's primary key. | `QueryBuilder` |
| <span id="method-selectExists"></span>[`selectExists()`](/docs/api/yii/db/querybuilder/index.md#method-selectExists) | Creates a SELECT EXISTS() SQL statement. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-setConditionClasses"></span>[`setConditionClasses()`](/docs/api/yii/db/querybuilder/index.md#method-setConditionClasses) | Setter for [`$conditionClasses`](/docs/api/yii/db/querybuilder/index.md#property-conditionClasses) property. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-setExpressionBuilders"></span>[`setExpressionBuilders()`](/docs/api/yii/db/querybuilder/index.md#method-setExpressionBuilders) | Setter for [`$expressionBuilders`](/docs/api/yii/db/querybuilder/index.md#property-expressionBuilders) property. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`truncateTable()`](#method-truncateTable) | Builds a SQL statement for truncating a DB table. | `QueryBuilder` |
| [`update()`](#method-update) | Creates an UPDATE SQL statement. | `QueryBuilder` |
| [`upsert()`](#method-upsert) | Creates an SQL statement to insert rows into a database table if they do not already exist (matching unique constraints), or update them if they do. | `QueryBuilder` |
| [`buildLimitOffsetValue()`](#method-buildLimitOffsetValue) protected | Builds a PostgreSQL row-limiting value for `OFFSET` / `FETCH` clauses. | `QueryBuilder` |
| <span id="method-concatUnionSql"></span>[`concatUnionSql()`](/docs/api/yii/db/querybuilder/index.md#method-concatUnionSql) protected | Concatenates the first `SELECT` statement with the UNION clauses built by [`buildUnion()`](/docs/api/yii/db/querybuilder/index.md#method-buildUnion). | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| [`defaultConditionClasses()`](#method-defaultConditionClasses) protected | Contains array of default condition classes. Extend this method, if you want to change default condition classes for the query builder. See [`$conditionClasses`](/docs/api/yii/db/querybuilder/index.md#property-conditionClasses) docs for details. | `QueryBuilder` |
| [`defaultExpressionBuilders()`](#method-defaultExpressionBuilders) protected | Contains array of default expression builders. Extend this method and override it, if you want to change default expression builders for this query builder. See [`$expressionBuilders`](/docs/api/yii/db/querybuilder/index.md#property-expressionBuilders) docs for details. | `QueryBuilder` |
| <span id="method-extractAlias"></span>[`extractAlias()`](/docs/api/yii/db/querybuilder/index.md#method-extractAlias) protected | Extracts table alias if there is one or returns false | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-hasLimit"></span>[`hasLimit()`](/docs/api/yii/db/querybuilder/index.md#method-hasLimit) protected | Checks to see if the given limit is effective. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-hasOffset"></span>[`hasOffset()`](/docs/api/yii/db/querybuilder/index.md#method-hasOffset) protected | Checks to see if the given offset is effective. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-prepareInsertSelectSubQuery"></span>[`prepareInsertSelectSubQuery()`](/docs/api/yii/db/querybuilder/index.md#method-prepareInsertSelectSubQuery) protected | Prepare select-subquery and field names for INSERT INTO ... SELECT SQL statement. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-prepareInsertValues"></span>[`prepareInsertValues()`](/docs/api/yii/db/querybuilder/index.md#method-prepareInsertValues) protected | Prepares a `VALUES` part for an `INSERT` SQL statement. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-prepareSelectQuery"></span>[`prepareSelectQuery()`](/docs/api/yii/db/querybuilder/index.md#method-prepareSelectQuery) protected | Performs driver-specific preparation after [`Query::prepare()`](/docs/api/yii/db/query/index.md#method-prepare). | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-prepareUpdateSets"></span>[`prepareUpdateSets()`](/docs/api/yii/db/querybuilder/index.md#method-prepareUpdateSets) protected | Prepares a `SET` parts for an `UPDATE` SQL statement. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-prepareUpsertColumns"></span>[`prepareUpsertColumns()`](/docs/api/yii/db/querybuilder/index.md#method-prepareUpsertColumns) protected |  | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |
| <span id="method-prepareUpsertSets"></span>[`prepareUpsertSets()`](/docs/api/yii/db/querybuilder/index.md#method-prepareUpsertSets) protected | Prepares the `SET` assignments for the update branch of an upsert statement. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |

## Constants

| Constant | Value | Description | Defined by |
| --- | --- | --- | --- |
| <span id="const-INDEX_UNIQUE"></span>`INDEX_UNIQUE` | `'unique'` | Defines a UNIQUE index for [`createIndex()`](/docs/api/yii/db/pgsql/querybuilder/index.md#method-createIndex). Available since 2.0.6. | `QueryBuilder` |
| <span id="const-INDEX_B_TREE"></span>`INDEX_B_TREE` | `'btree'` | Defines a B-tree index for [`createIndex()`](/docs/api/yii/db/pgsql/querybuilder/index.md#method-createIndex). Available since 2.0.6. | `QueryBuilder` |
| <span id="const-INDEX_HASH"></span>`INDEX_HASH` | `'hash'` | Defines a hash index for [`createIndex()`](/docs/api/yii/db/pgsql/querybuilder/index.md#method-createIndex). Available since 2.0.6. | `QueryBuilder` |
| <span id="const-INDEX_GIST"></span>`INDEX_GIST` | `'gist'` | Defines a GiST index for [`createIndex()`](/docs/api/yii/db/pgsql/querybuilder/index.md#method-createIndex). Available since 2.0.6. | `QueryBuilder` |
| <span id="const-INDEX_GIN"></span>`INDEX_GIN` | `'gin'` | Defines a GIN index for [`createIndex()`](/docs/api/yii/db/pgsql/querybuilder/index.md#method-createIndex). Available since 2.0.6. | `QueryBuilder` |
| <span id="const-PARAM_PREFIX"></span>[`PARAM_PREFIX`](/docs/api/yii/db/querybuilder/index.md#const-PARAM_PREFIX) | `':qp'` | The prefix for automatically generated query binding parameters. | [`yii\db\QueryBuilder`](/docs/api/yii/db/querybuilder/index.md) |

## Method details

### alterColumn() <span id="method-alterColumn"></span>

```php
public function alterColumn(string $table, string $column, yii\db\ColumnSchemaBuilder|string $type): string
```

Builds a SQL statement for changing the definition of a column.

Supports three input modes for `$type`.
- A [`ColumnSchemaBuilder`](/docs/api/yii/db/columnschemabuilder/index.md) produces a structured, multi-action `ALTER TABLE` statement that changes the
  column type and applies any nullability, default, `CHECK`, and `UNIQUE` state carried by the builder; `CHECK`
  and `UNIQUE` constraints are recreated under stable names derived from the table and column, replacing
  same-named constraints.
- A string starting with a PostgreSQL per-column action keyword; `SET ...`, `DROP ...`, `RESET (...)`,
  `RESTART [WITH n]`, or `ADD GENERATED ...`, is emitted verbatim as a single action; PostgreSQL parses its
  contents.
- Any other string changes only the column type and no longer implicitly drops `DEFAULT` or `NOT NULL`.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$table` | `string` | The table whose column is to be changed. The table name will be properly quoted by the method. |
| `$column` | `string` | The name of the column to be changed. The name will be properly quoted by the method. |
| `$type` | [`yii\db\ColumnSchemaBuilder`](/docs/api/yii/db/columnschemabuilder/index.md)`\|string` | The new column definition. A [`ColumnSchemaBuilder`](/docs/api/yii/db/columnschemabuilder/index.md) carries the structured column state; a string is resolved through [`getColumnType()`](/docs/api/yii/db/querybuilder/index.md#method-getColumnType) to the physical column type unless it is a `SET`/`DROP`/`RESET`/`RESTART`/`ADD GENERATED` action, which is emitted verbatim. |

**Returns**

`string`: The SQL statement for changing the definition of a column.

### batchInsert() <span id="method-batchInsert"></span>

```php
public function batchInsert(mixed $table, mixed $columns, mixed $rows, mixed &$params = []): string
```

Generates a batch INSERT SQL statement.

For example,

```
$sql = $queryBuilder->batchInsert('user', ['name', 'age'], [
    ['Tom', 30],
    ['Jane', 20],
    ['Linda', 25],
]);
```

Note that the values in each row must match the corresponding column names.

The method will properly escape the column names, and quote the values to be inserted.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$table` | `mixed` | The table that new rows will be inserted into. |
| `$columns` | `mixed` | The column names |
| `$rows` | `mixed` | The rows to be batch inserted into the table |
| `$params` | `mixed` | The binding parameters. This parameter exists since 2.0.14 |

**Returns**

`string`: The batch INSERT SQL statement

### buildLimit() <span id="method-buildLimit"></span>

```php
public function buildLimit(int|yii\db\ExpressionInterface|null $limit, int|yii\db\ExpressionInterface|null $offset): string
```

Builds the LIMIT and OFFSET clauses for a SELECT query using the PostgreSQL `OFFSET ... FETCH` syntax.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$limit` | `int\|`[`yii\db\ExpressionInterface`](/docs/api/yii/db/expressioninterface/index.md)`\|null` | The LIMIT value. `null` or a negative value means no limit; `0` is valid and emits `FETCH NEXT 0 ROWS ONLY`. |
| `$offset` | `int\|`[`yii\db\ExpressionInterface`](/docs/api/yii/db/expressioninterface/index.md)`\|null` | The OFFSET value. `null` or `0` means no offset. |

**Returns**

`string`: The LIMIT and OFFSET clauses built for PostgreSQL `14+`.

### checkIntegrity() <span id="method-checkIntegrity"></span>

```php
public function checkIntegrity(bool $check = true, string $schema = '', string $table = ''): string
```

Builds a SQL statement for enabling or disabling integrity checks.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$check` | `bool` | Whether to enable or disable integrity checks. |
| `$schema` | `string` | The schema containing the tables. |
| `$table` | `string` | The table name. An empty string applies the operation to all tables in the schema. |

**Returns**

`string`: The SQL statement for changing the integrity-check state.

### createIndex() <span id="method-createIndex"></span>

```php
public function createIndex(string $name, string $table, string|array $columns, bool|string $unique = false): string
```

Builds a SQL statement for creating a new index.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$name` | `string` | The name of the index. The name will be properly quoted by the method. |
| `$table` | `string` | The table that the new index will be created for. The table name will be properly quoted by the method. |
| `$columns` | `string\|array` | The column(s) that should be included in the index. If there are multiple columns, separate them with commas or use an array to represent them. Each column name will be properly quoted by the method, unless a parenthesis is found in the name. |
| `$unique` | `bool\|string` | Whether to make this a UNIQUE index constraint. You can pass `true` or [`INDEX_UNIQUE`](/docs/api/yii/db/pgsql/querybuilder/index.md#const-INDEX_UNIQUE) to create a unique index, `false` to make a non-unique index using the default index type, or one of the following constants to specify the index method to use: [`INDEX_B_TREE`](/docs/api/yii/db/pgsql/querybuilder/index.md#const-INDEX_B_TREE), [`INDEX_HASH`](/docs/api/yii/db/pgsql/querybuilder/index.md#const-INDEX_HASH), [`INDEX_GIST`](/docs/api/yii/db/pgsql/querybuilder/index.md#const-INDEX_GIST), [`INDEX_GIN`](/docs/api/yii/db/pgsql/querybuilder/index.md#const-INDEX_GIN). |

**Returns**

`string`: The SQL statement for creating a new index.

**See also**

- <https://www.postgresql.org/docs/current/sql-createindex.html>

### dropIndex() <span id="method-dropIndex"></span>

```php
public function dropIndex(string $name, string $table): string
```

Builds a SQL statement for dropping an index.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$name` | `string` | The name of the index to be dropped. The name will be properly quoted by the method. |
| `$table` | `string` | The table whose index is to be dropped. The name will be properly quoted by the method. |

**Returns**

`string`: The SQL statement for dropping an index.

### insert() <span id="method-insert"></span>

```php
public function insert(mixed $table, mixed $columns, mixed &$params): string
```

Creates an INSERT SQL statement.

For example,
```
$sql = $queryBuilder->insert('user', [
    'name' => 'Sam',
    'age' => 30,
], $params);
```
The method will properly escape the table and column names.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$table` | `mixed` | The table that new rows will be inserted into. |
| `$columns` | `mixed` | The column data (name => value) to be inserted into the table or instance of [Query](/docs/api/yii/db/query/index.md) to perform INSERT INTO ... SELECT SQL statement. Passing of [Query](/docs/api/yii/db/query/index.md) is available since version 2.0.11. |
| `$params` | `mixed` | The binding parameters that will be generated by this method. They should be bound to the DB command later. |

**Returns**

`string`: The INSERT SQL

### renameTable() <span id="method-renameTable"></span>

```php
public function renameTable(string $oldName, string $newName): string
```

Builds a SQL statement for renaming a DB table.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$oldName` | `string` | The table to be renamed. The name will be properly quoted by the method. |
| `$newName` | `string` | The new table name. The name will be properly quoted by the method. |

**Returns**

`string`: The SQL statement for renaming a DB table.

### resetSequence() <span id="method-resetSequence"></span>

```php
public function resetSequence(string $tableName, int|null $value = null): string
```

Creates a SQL statement for resetting the sequence value of a table's primary key.

The sequence will be reset such that the primary key of the next new row inserted will have the specified value
or `1`.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$tableName` | `string` | The name of the table whose primary key sequence will be reset. |
| `$value` | `int\|null` | The integer value for the primary key of the next new row inserted. If this is not set, the next new row's primary key will have a value `1`. |

**Returns**

`string`: The SQL statement for resetting sequence.

**Throws**

- [`yii\base\InvalidArgumentException`](/docs/api/yii/base/invalidargumentexception/index.md): if the table does not exist or there is no sequence associated with the table.

### truncateTable() <span id="method-truncateTable"></span>

```php
public function truncateTable(string $table): string
```

Builds a SQL statement for truncating a DB table.

Explicitly restarts identity for PGSQL to be consistent with other databases which all do this by default.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$table` | `string` | The table to be truncated. The name will be properly quoted by the method. |

**Returns**

`string`: The SQL statement for truncating a DB table.

### update() <span id="method-update"></span>

```php
public function update(mixed $table, mixed $columns, mixed $condition, mixed &$params): string
```

Creates an UPDATE SQL statement.

For example,

```
$params = [];
$sql = $queryBuilder->update('user', ['status' => 1], 'age > 30', $params);
```

The method will properly escape the table and column names.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$table` | `mixed` | The table to be updated. |
| `$columns` | `mixed` | The column data (name => value) to be updated. |
| `$condition` | `mixed` | The condition that will be put in the WHERE part. Please refer to [`Query::where()`](/docs/api/yii/db/query/index.md#method-where) on how to specify condition. |
| `$params` | `mixed` | The binding parameters that will be modified by this method so that they can be bound to the DB command later. |

**Returns**

`string`: The UPDATE SQL

### upsert() <span id="method-upsert"></span>

```php
public function upsert(mixed $table, mixed $insertColumns, mixed $updateColumns, mixed &$params): string
```

Creates an SQL statement to insert rows into a database table if
they do not already exist (matching unique constraints),
or update them if they do.

For example,

```
$sql = $queryBuilder->upsert('pages', [
    'name' => 'Front page',
    'url' => 'https://example.com/', // url is unique
    'visits' => 0,
], [
    'visits' => new \yii\db\Expression('visits + 1'),
], $params);
```

The method will properly escape the table and column names.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$table` | `mixed` | The table that new rows will be inserted into/updated in. |
| `$insertColumns` | `mixed` | The column data (name => value) to be inserted into the table or instance of [`Query`](/docs/api/yii/db/query/index.md) to perform `INSERT INTO ... SELECT` SQL statement. |
| `$updateColumns` | `mixed` | The column data (name => value) to be updated if they already exist. If `true` is passed, the column data will be updated to match the insert column data. If `false` is passed, no update will be performed if the column data already exists. |
| `$params` | `mixed` | The binding parameters that will be generated by this method. They should be bound to the DB command later. |

**Returns**

`string`: The resulting SQL.

**Throws**

- [`yii\base\NotSupportedException`](/docs/api/yii/base/notsupportedexception/index.md): if this is not supported by the underlying DBMS.

**Since**

2.0.14

**See also**

- <https://www.postgresql.org/docs/current/sql-insert.html#SQL-ON-CONFLICT>

### buildLimitOffsetValue() <span id="method-buildLimitOffsetValue"></span>

```php
protected function buildLimitOffsetValue(int|yii\db\Expression $value): string
```

Builds a PostgreSQL row-limiting value for `OFFSET` / `FETCH` clauses.

PostgreSQL allows scalar expressions in `OFFSET` and `FETCH`, but arithmetic expressions must be enclosed in
parentheses to avoid syntax ambiguity (for example, `FETCH NEXT (1 + 1) ROWS ONLY`).

Only `int` and [`Expression`](/docs/api/yii/db/expression/index.md) are supported. Other [`ExpressionInterface`](/docs/api/yii/db/expressioninterface/index.md) implementations
([`JsonExpression`](/docs/api/yii/db/jsonexpression/index.md), [`ArrayExpression`](/docs/api/yii/db/arrayexpression/index.md), [`PdoValue`](/docs/api/yii/db/pdovalue/index.md)) are not valid row-count values
and are not handled here; passing them produces undefined SQL.

**Parameters**

| Parameter | Type | Description |
| --- | --- | --- |
| `$value` | `int\|`[`yii\db\Expression`](/docs/api/yii/db/expression/index.md) | The row-limiting value. |

**Returns**

`string`: The value SQL.

### defaultConditionClasses() <span id="method-defaultConditionClasses"></span>

```php
protected function defaultConditionClasses(): array
```

Contains array of default condition classes. Extend this method, if you want to change
default condition classes for the query builder. See [`$conditionClasses`](/docs/api/yii/db/querybuilder/index.md#property-conditionClasses) docs for details.

**Returns**

`array`

**Since**

2.0.14

### defaultExpressionBuilders() <span id="method-defaultExpressionBuilders"></span>

```php
protected function defaultExpressionBuilders(): array
```

Contains array of default expression builders. Extend this method and override it, if you want to change
default expression builders for this query builder. See [`$expressionBuilders`](/docs/api/yii/db/querybuilder/index.md#property-expressionBuilders) docs for details.

**Returns**

`array`

**Since**

2.0.14