dropDefaultValue

Removes the database default value for a column.

Run `dropDefaultValue`

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

Name	Description	Required for	Supports	Since
`catalogName`	Name of the catalog		all	3.0
`columnDataType`	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.	informix	all
`columnName`	Name of the column to drop the default value from	all	all
`schemaName`	Name of the schema		all
`tableName`	Name of the table containing the column to drop the default value from	all	all

--liquibase formatted sql
--changeset liquibase-docs:dropDefaultValue-example
ALTER TABLE cat.person
ALTER id
DROP DEFAULT;

--liquibase formatted sql
--changeset liquibase-docs:dropDefaultValue-example
ALTER TABLE cat.person
ALTER id
DROP DEFAULT;