Structure

SQLAlterColumnDefinitionType

A clause specifying a new data type to be applied to an existing column.

struct SQLAlterColumnDefinitionType

Overview

This expression is used by modifyColumn(_:type:_:) to abstract over the use of alterColumnDefinitionTypeKeyword in the dialect’s alterTableSyntax. The serialized SQL is of the form:

column alterColumnDefinitionTypeKeyword dataType
-- Given column == SQLIdentifier("col"), dataType == SQLDataTyoe.text:
-- PostgreSQL: "col" SET DATA TYPE TEXT
--      MySQL: `col` TEXT

Users should not use this expression. It is an oversight that it is public API; it will eventually be removed.

Topics

Initializers

init(column:dataType:)
Create a new SQLAlterColumnDefinitionType expression.

Instance Properties

var column: any SQLExpression
The column to alter.
var dataType: any SQLExpression
The new data type.

Instance Methods

func serialize(to: inout SQLSerializer)
Invoked when a request is made to serialize the expression to raw SQL.

Relationships

Conforms To

SQLExpression
Swift.Sendable
Swift.SendableMetatype

struct SQLColumnAssignment
Encapsulates a column_name=value expression in the context of an UPDATE query’s value assignment list. This is distinct from an SQLBinaryExpression using the .equal operator in that the left side must be an unqualified column name, the operator must be =, and the right side may use SQLExcludedColumn when the assignment appears in the assignments list of a SQLConflictAction.update(assignments:predicate:) specification.
enum SQLColumnConstraintAlgorithm
Column-level data constraints.
struct SQLColumnDefinition
A clause expressing a column definition, for use when creating and altering tables.
struct SQLCommonTableExpression
A clause describing a single Common Table Expressions, which in itws simplest form provides additional data to a primary query in the same way as joining to a subquery.
struct SQLCommonTableExpressionGroup
A clause representing a group of one or more SQLCommonTableExpressions.
enum SQLConflictAction
An action to take when an INSERT query encounters a unique constraint violation.
struct SQLConflictResolutionStrategy
Specifies a conflict resolution strategy and associated conditions for an INSERT query. An INSERT with a conflict strategy is often refered to as an UPSERT (“insert or update”). Databases are not required to support any given subset of upsert functionality, or any at all.
enum SQLDropBehavior
Specifies a behavior when performing a DROP operation on a database object which is referenced by other objects.
struct SQLEnumDataType
Represents a data type which specifies an enumeration in the database.
struct SQLExcludedColumn
An expression appearing on the right side of a column assignment which, when the assignment list is part of an upsert’s update acion, refers to the value which was originally to be inserted for the given column.
struct SQLForeignKey
A complete FOREIGN KEY constraint specification.
struct SQLInsertModifier
Simple helper for working around MySQL’s refusal to implement standard SQL. Only emits SQL when needed.
struct SQLJoin
Encapsulates a single SQL JOIN, specifying the join type, the right-side table, and condition.
enum SQLJoinMethod
The method used by a table join clause.
enum SQLLockingClause
An SQL locking clause.