`column`

The column tag specifies information about columns you create or modify with Change Types like addColumn, createTable, createIndex, dropColumn, insert, loadData, loadUpdateData, and update. You can specify one or multiple columns in a single changeset. Find all of the data types available to Liquibase users in the Available Attributes table below.

Uses

Use the column tag to define the behavior of your table columns. For example, with a Change Type like addColumn, setting the defaultValue attribute on a column specifies its default value. Setting the value attribute sets all rows existing to the specified value (such a string) without modifying the column default. Setting the valueComputed attribute as a function name or name of a computed column sets all rows to the value returned (computed) by that function.

You can use the column tag with createIndex to create an index on a particular table column (<column name="address"/>). You can also create an index on a computed version of that column (<column name="lower(address)" computed="true"/>).

Some Change Type that interact with table columns, like addPrimaryKey and modifyDataType, do not use the <column> tag. Instead, they use their own attributes like columnNames and columnName respectively to refer to existing columns specified with the <column> tag.

Available attributes

Note: You can use the <column> tag with multiple Change Types, but not every attribute is valid for every Change Type. For example, if you use column with createTable, both name and value are valid attributes. However, if you use column with createIndex, name is valid but value is not.

Attribute	Description
`name`	Name of the column
`type`	Data type of the column. To help make scripts database-independent, Liquibase automatically converts the following generic data types to the correct database implementation: `BIGINT`, `BLOB`, `BOOLEAN`, `CHAR`, `CLOB`, `CURRENCY`, `DATE`, `DATETIME`, `DECIMAL`, `DOUBLE`, `FLOAT`, `INT`, `MEDIUMINT`, `NCHAR`, `NUMBER`, `NVARCHAR`, `SMALLINT`, `TIME`, `TIMESTAMP`, `TINYINT`, `UUID`, `VARCHAR`, `XML`. Also, specifying a `java.sql.Types.` type is converted to the correct type as well. For example: `java.sql.Types.TIMESTAMP` `java.sql.Types.VARCHAR(255)` For Snowflake, Liquibase also implements `BINARY`, `TIME`, and `TIMESTAMP_NTZ`. For Databricks, Liquibase also implements `ARRAY<INT>` and `ARRAY<STRING>`, `MAP`, and `STRUCT` variable types. Note:* To specify a complex Databricks type like `ARRAY<STRING>` in an XML changelog, you must specify the escape sequences `<` and `>` rather than `<` and `>`. See `createTable`. For more information, see Liquibase Data Type Handling.
`value`	Sets all fields in the column to the specified value. The value will be surrounded by quote marks. Nested quote marks will be escaped.
`afterColumn`	Controls the placement of a new column added with the `addColumn` Change Type. See also: removeChangeSetProperty. Note: Only one of `beforeColumn`, `afterColumn`, or `position` is allowed.
`autoIncrement`	A boolean value which specifies how much to increment the column by each time a new record is inserted into the table. Useful to generate unique primary keys for each record. Ignored on databases that do not support auto-increment or identity functionality. `incrementBy` is the attribute that contains the integer increment.
`beforeColumn`	Controls the placement of a new column added with the `addColumn` Change Type. See also: removeChangeSetProperty. Note: Only one of `beforeColumn`, `afterColumn`, or `position` is allowed. Not supported in MySQL.
`computed`	Boolean specifying whether the value in `name` is computed (a function) rather than a column name (a string). Default: `false`. With some Change Types, like `addColumn`, `computed` tells Liquibase whether the `type` can be added without specifying a type.
`defaultValue`	The default value for fields in the column. Either this property or one of the other `defaultValue*` properties are required.
`defaultValueBoolean`	The boolean value that will be used if no value is provided. Note: Only one of the `defaultValue*` attributes is allowed.
`defaultValueComputed`	The default value that is returned from a function or procedure call of the same type as the column. Contains the function or column name to call. Differs from `defaultValue` by returning the value of the function or column you specify instead of the name of the function/column as a string. Can also perform operations on the returned value. Note: Only one of the `defaultValue*` attributes is allowed.
`defaultValueConstraintName`	Sets a unique name for default constraint used for a specific column. It works only along with any of the `defaultValue*` attributes listed.
`defaultValueDate`	The default date and time value for column. The value is specified in one of the following forms: `YYYY-MM-DD`, `hh:mm:ss`, or `YYYY-MM-DDThh:mm:ss`. Note: Only one of the `defaultValue*` attributes is allowed.
`defaultValueNumeric`	The default value for a column of a numeric type. For example: integer, bigint, bigdecimal, and others. Note: Only one of the `defaultValue*` attributes is allowed.
`descending`	Defines whether a column is in descending order in the index if it is used in a `createIndex` command. Default value: `false` (ascending).
`encoding`	The name of the encoding (specified in java.nio.Charset javadoc, e.g. `"UTF-8"`) of the CLOB file (specified in `valueClobFile`) contents. Note: This attribute is used only when `valueClobFile` attribute is specified. Otherwise, it is ignored.
`generationType`	Type of the generation in `GENERATED %s AS IDENTITY`. Default: "`\|`".
`included`	Liquibase 4.30.0+. In MSSQL databases, an index can contain "included" ("non-key") columns in a SQL `INCLUDED` clause. This parameter controls whether Liquibase treats a column in the `createIndex` Change Type as included. If `true`, when Liquibase deploys the index to your database, it specifies the column in the SQL `INCLUDED` clause. Default: `false`. For more information, see Create indexes with included columns. Note: This parameter is not to be confused with the `include` and `includeAll` tags.
`incrementBy`	Integer amount to increment by at each call with `autoIncrement`. Ignored on databases that do not support auto-increment or identity functionality.
`nullPlaceholder`	Liquibase 4.31.0+. Specifies a placeholder string for Liquibase to search for in a `loadData` CSV file. If the CSV contains the value you specified for `nullPlaceholder`, Liquibase replaces that value with a `NULL` SQL reference.
`position`	Controls the placement of a new column added with the `addColumn` Change Type. See also: removeChangeSetProperty. Note: Only one of `beforeColumn`, `afterColumn`, or `position` is allowed.
`remarks`	A short descriptive comment
`startWith`	Initial integer value of the increment. Ignored on databases that do not support auto-increment or identity functionality.
`valueBlobFile`	The path to a file whose contents will be written as a BLOB (binary large object). The path to the changelog file location must be either absolute or relative. An example of an absolute path is: `/usr/local/somefile.dat` on Unix or `c:\Directory\somefile.dat` on Windows. Note: Refer to java.io.File javadoc for the details of what to consider relative or absolute path.
`valueBoolean`	The boolean value that will be set whether a value is provided or not.
`valueClobFile`	The path to a file whose contents will be written as a CLOB (character large object). The path to the changelog file location must be either absolute or relative. An example of an absolute path is: `/usr/local/somefile.dat` on Unix or `c:\Directory\somefile.dat` on Windows. Note: Refer to java.io.File javadoc for the details of what to consider relative or absolute path.
`valueComputed`	The value that is returned from a function or procedure call. Contains the function or column name to call. Differs from `value` by returning the value of the function or column you specify instead of the name of the function/column as a string. Can also perform operations on the returned value.
`valueDate`	The date and time value to set the column to. Accepts the following formats: `YYYY-MM-DD`, `hh:mm:ss`, or `YYYY-MM-DDThh:mm:ss`.
`valueNumeric`	The numeric value to set fields in the column to. The value will not be escaped and will not be nested in quote marks.

Available sub-tags

Tag	Description
`constraints`	Constraint definitions

Constraints sub-tag

The <constraints> tag contains information about constraints on the column.

Available attributes

Attribute	Description
`checkConstraint`	Defines whether to validate the defined check constraint. Default: database-dependent
`deleteCascade`	Sets `DELETE CASCADE`.
`deferrable`	Defines whether constraints are deferrable. Default: database-dependent
`foreignKeyName`	The foreign key name.
`initiallyDeferred`	Defines whether constraints are initially deferred. Default: database-dependent
`notNullConstraintName`	The `NOT NULL CONSTRAINT` name.
`nullable`	Defines whether the column is nullable. Default: database-dependent
`primaryKey`	Defines whether the column is a primary key. Default: database-dependent
`primaryKeyName`	The name of the primary key. Note: This attribute is ignored in BigQuery databases.
`primaryKeyTablespace`	The tablespace to use for the defined primary key.
`unique`	Defines whether a unique clause should be applied. Default: database-dependent
`uniqueConstraintName`	Name of the constraint (unique)
`references`	The foreign key definition. (This value is used as-is in the generated SQL so ensure all required quoting or other required syntax is being used. If you do not need to specify the exact SQL, use `referencedTableName` and `referencedColumnNames` instead)
`referencedColumnNames`	Name of the column
`referencedTableCatalogName`	Name of the catalog
`referencedTableName`	Name of the table
`referencedTableSchemaName`	Name of the schema
`validateForeignKey`	Defines whether to validate the defined foreign key constraint. Default: database-dependent
`validateNullable`	Defines whether to validate the defined not null constraint. Default: database-dependent
`validatePrimaryKey`	Defines whether to validate the defined primary key constraint. Default: database-dependent
`validateUnique`	Defines whether to validate the defined unique constraint. Default: database-dependent

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

--liquibase formatted sql

--changeset liquibase-docs:addColumn-example
ALTER TABLE cat.person ADD address VARCHAR(255) NULL,
ADD name VARCHAR(50) NOT NULL;

databaseChangeLog:
- changeSet:
    id: addColumn-example
    author: liquibase-docs
    changes:
      - addColumn:
          tableName: person
          columns:
          - column:
              name: middlename
              type: varchar(50)

{
    "databaseChangeLog": [
        {
            "changeSet": {
                "id": "addColumn-example",
                "author": "liquibase-docs",
                "changes": [
                    {
                        "addColumn": {
                            "catalogName": "cat",
                            "columns": [
                                {
                                    "column": {
                                        "name": "address",
                                        "type": "varchar(255)"
                                    }
                                },
                                {
                                    "column": {
                                        "constraints": {
                                            "nullable": false
                                        },
                                        "name": "name",
                                        "type": "varchar(50)"
                                    }
                                }
                            ],
                            "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="addColumn-example">
        <addColumn catalogName="cat"
            schemaName= "public"
            tableName="person">
            <column name="address" type="varchar (255) "/>
                <constraints nullable="false" unique="true" uniqueConstraintName="first_column_is_unique"/>
            </column>					
            <column name="person_id" type="int">
                <constraints references="id" referencedTableName="person" foreignKeyName="fk_person"/>
            </column>
        </addColumn>
    </changeSet>

</databaseChangeLog>

column

Uses

Available attributes

Available sub-tags

Constraints sub-tag

Available attributes

Related links

`column`