Alter

The alter method loads up an existing table in order to make modifications. These modifications may include adding, renaming, or dropping columns and constraints.

Calling multiple methods inside a single alter callback creates multiple SQL statements to be executed. qb takes care of this execution for you by default.

The following methods off of Blueprint let you modify the table inside the callback:

addColumn

Add a new column to an existing table. Takes a Column instance as the only argument.

Example:

SchemaBuilder

SQL (MySQL)

raw

An escape hatch to directly insert any sql in to the statement.

Example:

SchemaBuilder

SQL (MySQL)

dropColumn

Drop a column on an existing table.

Example:

SchemaBuilder

SQL (MySQL)

modifyColumn

Modify an existing column on a table.

Example:

SchemaBuilder

SQL (MySQL)

renameColumn

Rename a column on a table. A full Column instance is required as the second argument for Grammars that need to redeclare the column definition when renaming.

Example:

SchemaBuilder

SQL (MySQL)

addConstraint

Example:

SchemaBuilder

SQL (MySQL)

dropConstraint

Drop an existing table constraint.

Example:

SchemaBuilder

SQL (MySQL)

dropIndex

Drop an existing index.

Example:

SchemaBuilder

SQL (MySQL)

SQL (SQL Server)

renameConstraint

Rename an existing table constraint.

Example:

SchemaBuilder

SQL (MySQL)

renameTable

Rename an existing table.

Example:

SchemaBuilder

SQL (MySQL)

rename

An alias for renameTable.

Example:

SchemaBuilder

SQL (MySQL)