changeColumn()

Signature

changeColumn() — returns void

Available in: migration Category: Migration Functions

Description

Changes the definition of an existing column in a database table. This function is used in migration CFCs to update column properties such as type, size, default value, nullability, precision, and scale.

Parameters

Name	Type	Required	Default	Description
table	string	yes	—	The Name of the table where the column is
columnName	string	yes	—	THe name of the column
columnType	string	yes	—	The type of the column
afterColumn	string	no	—	The name of the column which this column should be inserted after
referenceName	string	no	—	Name for reference column, see documentation for references function, required if columnType is ‘reference’
default	string	no	—	Default value for this column
allowNull	boolean	no	—	Whether to allow NULL values
limit	numeric	no	—	Character or integer size limit for column
precision	numeric	no	—	(For decimal type) the maximum number of digits allow
scale	numeric	no	—	(For decimal type) the number of digits to the right of the decimal point
addColumns	boolean	no	false	if true, attempts to add columns and database will likely throw an error if column already exists

Examples

1. Change the type and limit of a column
changeColumn(table='members', columnName='status', columnType='string', limit=50);

2. Change a decimal column’s precision and scale
changeColumn(table='products', columnName='price', columnType='decimal', precision=10, scale=2);

3. Change a column to allow NULL and set a default value
changeColumn(table='users', columnName='nickname', columnType='string', limit=100, allowNull=true, default='Guest');

4. Move a column to a specific position in the table
changeColumn(table='orders', columnName='status', columnType='string', limit=20, afterColumn='orderDate');