addPrimaryKey

The addPrimaryKey Change Type adds a primary key out of an existing column or set of columns.

Uses

It is a best practice to normalize the data in your relational database by setting a primary key on one or more of the columns of a table. A table can only have one primary key, regardless of whether that key is single or composite. You can use the primary key to uniquely identify each row in the table.

Running the addPrimaryKey Change Type

To add a primary key to your table, follow these steps:

  1. Add the addPrimaryKey Change Type to your changeset with the needed attributes, as shown in the examples.
  2. Deploy your changeset by running the update command:
  3. liquibase update

Add new column to existing primary key

If you have already set a primary key on a column, but you realize that column by itself does not provide sufficient uniqueness to each row, you can add an additional column to the existing key. Liquibase returns an error if you try to create a new primary key because one already exists. Instead, follow these steps:

  1. Drop the existing primary key with the dropPrimaryKey Change Type:
    <changeSet author="liquibase-docs" id="dropPrimaryKey-example">
        <dropPrimaryKey  tableName= "existing_table" constraintName="primary_key_constraint"/>
    </changeSet>
  2. Add new column to the existing table with the addColumn Change Type:
    <changeSet author="liquibase-docs" id="addColumn-example"> 
        <addColumn tableName="existing_table">
            <column name="new_column" type="VARCHAR(256)">
                <constraints nullable="false"/>
            </column>
        </addColumn>
    </changeSet>
  3. Add a composite primary key to the table, including both the new and old columns:
    <changeSet author="liquibase-docs" id="addPrimaryKey-example">
        <addPrimaryKey tableName="existing_table" columnNames="existing_column,new_column" constraintName="primary_key_constraint"/>
    </changeSet>
  4. Deploy your changes:
    liquibase update

Available attributes

Name Description Required for Supports
catalogName

Name of the catalog

all
clustered

Boolean. Whether to create a clustered index

all
columnNames Name of the column(s) to create the primary key on. Comma separated if multiple all all
constraintName Name of the constraint for the primary key all
forIndexCatalogName Name of the catalog of the index to associate with the primary key all
forIndexName Name of the index to associate with the primary key db2, db2z, oracle
forIndexSchemaName Name of the schema of the index to associate with the primary key all
schemaName

Name of the schema

all
tableName Name of the table to create the primary key on all all
tablespace

Name of the tablespace to use for the primary key

all
validate

Set to true if the constraint has ENABLE VALIDATE set, or false if the constraint has ENABLE NOVALIDATE set.

all

Examples

<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="addPrimaryKey-example">
        <addPrimaryKey  catalogName="cat"
            clustered="true"
            columnNames="id, name"
            constraintName="pk_person"
            forIndexName="A String"
            schemaName="public"
            tableName="person"
            tablespace="A String"
            validate="true"/>
    </changeSet>

</databaseChangeLog>
databaseChangeLog:
-  changeSet:
    id:  addPrimaryKey-example
    author:  liquibase-docs
    changes:
    -  addPrimaryKey:
        catalogName:  cat
        clustered:  true
        columnNames:  id, name
        constraintName:  pk_person
        forIndexName:  A String
        schemaName:  public
        tableName:  person
        tablespace:  A String
        validate:  true
{
    "databaseChangeLog": [
        {
            "changeSet": {
                "id": "addPrimaryKey-example",
                "author": "liquibase-docs",
                "changes": [
                    {
                        "addPrimaryKey": {
                            "catalogName": "cat",
                            "clustered": true,
                            "columnNames": "id, name",
                            "constraintName": "pk_person",
                            "forIndexName": "A String",
                            "schemaName": "public",
                            "tableName": "person",
                            "tablespace": "A String",
                            "validate": true
                        }
                    }
                ]
            }
        }
    ]
}
--liquibase formatted sql

--changeset liquibase-docs:addPrimaryKey-example
ALTER  TABLE  cat.person  ADD  PRIMARY  KEY  (id, name);

Database support

Database Notes Auto Rollback
DB2/LUW Supported Yes
DB2/z Supported Yes
Derby Supported Yes
Firebird Supported Yes
H2 Supported Yes
HyperSQL Supported Yes
INGRES Supported Yes
Informix Supported Yes
MariaDB Supported Yes
MySQL Supported Yes
Oracle Supported Yes
PostgreSQL Supported Yes
Snowflake Supported Yes
SQL Server Supported Yes
SQLite Not Supported No
Sybase Supported Yes
Sybase Anywhere Supported Yes