Skip to main content
The AlterTableBuilder class is used to construct ALTER TABLE queries. It provides a fluent API for modifying tables, adding or dropping columns, and managing constraints.

​
Methods

​
renameTo

Renames the table. 
renameTo(newTableName: string): AlterTableExecutor
​
newTableName
string
required
The new name for the table
​
returns
AlterTableExecutor
An executor for the alter table query

​
setSchema

Sets the schema for the table. 
setSchema(newSchema: string): AlterTableExecutor
​
newSchema
string
required
The new schema for the table
​
returns
AlterTableExecutor
An executor for the alter table query

​
alterColumn

Alters a column in the table. 
alterColumn(
  column: string,
  alteration: AlterColumnBuilderCallback
): AlterTableColumnAlteringBuilder
​
column
string
required
The name of the column to alter
​
alteration
AlterColumnBuilderCallback
required
A callback that receives an AlterColumnBuilder and returns modifications
​
returns
AlterTableColumnAlteringBuilder
A builder for additional column alterations

​
dropColumn

Drops a column from the table. 
dropColumn(column: string): AlterTableColumnAlteringBuilder
​
column
string
required
The name of the column to drop
​
returns
AlterTableColumnAlteringBuilder
A builder for additional column alterations

​
renameColumn

Renames a column. 
renameColumn(
  column: string,
  newColumn: string
): AlterTableColumnAlteringBuilder
​
column
string
required
The current name of the column
​
newColumn
string
required
The new name for the column
​
returns
AlterTableColumnAlteringBuilder
A builder for additional column alterations

​
addColumn

Adds a new column to the table. 
addColumn(
  columnName: string,
  dataType: DataTypeExpression,
  build?: ColumnDefinitionBuilderCallback
): AlterTableColumnAlteringBuilder
​
columnName
string
required
The name of the column to add
​
dataType
DataTypeExpression
required
The data type of the column
​
build
ColumnDefinitionBuilderCallback
Optional callback to configure the column definition
​
returns
AlterTableColumnAlteringBuilder
A builder for additional column alterations

​
modifyColumn

Creates an ALTER TABLE MODIFY COLUMN query. The MODIFY COLUMN statement is only implemented by MySQL and Oracle. On other databases you should use the alterColumn method. 
modifyColumn(
  columnName: string,
  dataType: DataTypeExpression,
  build?: ColumnDefinitionBuilderCallback
): AlterTableColumnAlteringBuilder
​
columnName
string
required
The name of the column to modify
​
dataType
DataTypeExpression
required
The new data type for the column
​
build
ColumnDefinitionBuilderCallback
Optional callback to configure the column definition
​
returns
AlterTableColumnAlteringBuilder
A builder for additional column alterations

​
addUniqueConstraint

Adds a unique constraint for one or more columns. See CreateTableBuilder.addUniqueConstraint for more details. 
addUniqueConstraint(
  constraintName: string,
  columns: string[],
  build?: UniqueConstraintNodeBuilderCallback
): AlterTableExecutor
​
constraintName
string
required
The name of the constraint
​
columns
string[]
required
The columns to include in the unique constraint
​
build
UniqueConstraintNodeBuilderCallback
Optional callback to configure the constraint
​
returns
AlterTableExecutor
An executor for the alter table query

​
addCheckConstraint

Adds a check constraint. See CreateTableBuilder.addCheckConstraint for more details. 
addCheckConstraint(
  constraintName: string,
  checkExpression: Expression<any>,
  build?: CheckConstraintBuilderCallback
): AlterTableExecutor
​
constraintName
string
required
The name of the constraint
​
checkExpression
Expression<any>
required
The check expression
​
build
CheckConstraintBuilderCallback
Optional callback to configure the constraint
​
returns
AlterTableExecutor
An executor for the alter table query

​
addForeignKeyConstraint

Adds a foreign key constraint. Unlike CreateTableBuilder.addForeignKeyConstraint, this method returns the constraint builder and doesn’t take a callback as the last argument. This is because you can only add one column per ALTER TABLE query. 
addForeignKeyConstraint(
  constraintName: string,
  columns: string[],
  targetTable: string,
  targetColumns: string[],
  build?: ForeignKeyConstraintBuilderCallback
): AlterTableAddForeignKeyConstraintBuilder
​
constraintName
string
required
The name of the constraint
​
columns
string[]
required
The columns in this table
​
targetTable
string
required
The target table name
​
targetColumns
string[]
required
The columns in the target table
​
build
ForeignKeyConstraintBuilderCallback
Optional callback to configure the constraint
​
returns
AlterTableAddForeignKeyConstraintBuilder
A builder for the foreign key constraint

​
addPrimaryKeyConstraint

Adds a primary key constraint for one or more columns. See CreateTableBuilder.addPrimaryKeyConstraint for more details. 
addPrimaryKeyConstraint(
  constraintName: string,
  columns: string[],
  build?: PrimaryKeyConstraintBuilderCallback
): AlterTableExecutor
​
constraintName
string
required
The name of the constraint
​
columns
string[]
required
The columns to include in the primary key
​
build
PrimaryKeyConstraintBuilderCallback
Optional callback to configure the constraint
​
returns
AlterTableExecutor
An executor for the alter table query

​
dropConstraint

Drops a constraint from the table. 
dropConstraint(constraintName: string): AlterTableDropConstraintBuilder
​
constraintName
string
required
The name of the constraint to drop
​
returns
AlterTableDropConstraintBuilder
A builder for dropping constraints

​
renameConstraint

Renames a constraint. 
renameConstraint(
  oldName: string,
  newName: string
): AlterTableDropConstraintBuilder
​
oldName
string
required
The current name of the constraint
​
newName
string
required
The new name for the constraint
​
returns
AlterTableDropConstraintBuilder
A builder for the constraint operation

​
addIndex

Adds an index to the table. 
addIndex(indexName: string): AlterTableAddIndexBuilder
​
indexName
string
required
The name of the index to add
​
returns
AlterTableAddIndexBuilder
A builder for creating the index

​
Examples

db.schema.alterTable('person')
  .addIndex('person_email_index')
  .column('email')
  .unique()
  .execute()
Generated SQL (MySQL): 
alter table `person` add unique index `person_email_index` (`email`)

​
dropIndex

Drops an index from the table. 
dropIndex(indexName: string): AlterTableExecutor
​
indexName
string
required
The name of the index to drop
​
returns
AlterTableExecutor
An executor for the alter table query

​
Examples

db.schema.alterTable('person')
  .dropIndex('person_email_index')
  .execute()
Generated SQL (MySQL): 
alter table `person` drop index `test_first_name_index`

​
$call

Calls the given function passing this as the only argument. See CreateTableBuilder.$call for more details. 
$call<T>(func: (qb: this) => T): T
​
func
(qb: this) => T
required
A function that receives the builder and returns a value
​
returns
T
The return value of the provided function

Build docs developers (and LLMs) love

Get started for freeTalk to us