dropColumn

The dropColumn Change Type drops existing columns.

To drop a single column, use the simple form of this element where the tableName and columnName are specified as attributes.

To drop several columns, specify the tableName as an attribute, and then specify a set of nested <column> tags. If nested <column> tags are present, the columnName attribute will be ignored. Alternatively, you can use separate dropColumn statements to drop more than one column.

Run `dropColumn`

To run this Change Type, follow these steps:

Add the Change Type to your changeset, as shown in the examples on this page.
Specify any required attributes. Use the table on this page to see which ones your database requires.
Deploy your changeset by running the update command:

liquibase update

Available attributes

Name	Description	Required for	Supports	Since
`catalogName`	Name of the catalog		all	3.0
`columnName`	Name of the column to drop, if dropping a single column. Ignored if nested columns are defined		all
`schemaName`	Name of the schema		all
`tableName`	Name of the table containing the column to drop	all	all

Nested tags

Name Description Required for Supports Multiple allowed

Name	Description	Required for	Supports	Multiple allowed
`column`	Columns to be dropped if dropping multiple columns. If this is populated, the `columnName` attribute is ignored. Note: YAML and JSON changelogs using the `column` tag must nest it within a `columns` tag.		all	yes

column

Columns to be dropped if dropping multiple columns. If this is populated, the columnName attribute is ignored.

Note: YAML and JSON changelogs using the column tag must nest it within a columns tag.

all

yes

Examples

--liquibase formatted sql

--changeset liquibase-docs:dropColumn-example
ALTER  TABLE  cat.person  DROP  COLUMN  address;

databaseChangeLog:
-  changeSet:
    id:  dropColumn-example
    author:  liquibase-docs
    changes:
    -  dropColumn:
        catalogName:  cat
        columnName:  id
        columns:
        -  column:
            name:  address
        schemaName:  public
        tableName:  person

{
    "databaseChangeLog": [
        {
            "changeSet": {
                "id": "dropColumn-example",
                "author": "liquibase-docs",
                "changes": [
                    {
                        "dropColumn": {
                            "catalogName": "cat",
                            "columnName": "id",
                            "columns": [
                                {
                                    "column": {
                                        "name": "address"
                                    }
                                }
                            ],
                            "schemaName": "public",
                            "tableName": "person"
                        }
                    }
                ]
            }
        }
    ]
}

<databaseChangeLog
    xmlns="http://www.liquibase.org/xml/ns/dbchangelog"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:ext="http://www.liquibase.org/xml/ns/dbchangelog-ext"
    xmlns:pro="http://www.liquibase.org/xml/ns/pro"
    xsi:schemaLocation="http://www.liquibase.org/xml/ns/dbchangelog
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-latest.xsd
        http://www.liquibase.org/xml/ns/dbchangelog-ext
        http://www.liquibase.org/xml/ns/dbchangelog/dbchangelog-ext.xsd
        http://www.liquibase.org/xml/ns/pro
        http://www.liquibase.org/xml/ns/pro/liquibase-pro-latest.xsd">

    <changeSet author="liquibase-docs" id="dropColumn-example">
        <dropColumn catalogName="cat"
                       columnName="id"
                       schemaName="public"
                       tableName="person">
            <column name="address1"/>
        </dropColumn>
        <dropColumn catalogName="cat"
	                   columnName="id"
	                   schemaName="public"
	                   tableName="person">
	        <column name="address2"/>
        </dropColumn>
    </changeSet>

</databaseChangeLog>

Database support