modifyDataType

<changeSet  author="liquibase-docs"  id="modifyDataType-example">  
    <modifyDataType  catalogName="cat"  
            columnName="id"  
            newDataType="int"  
            schemaName="public"  
            tableName="person"/>  
</changeSet>

changeSet:  
  id:  modifyDataType-example  
  author:  liquibase-docs  
  changes:  
  -  modifyDataType:  
      catalogName:  cat  
      columnName:  id  
      newDataType:  int  
      schemaName:  public  
      tableName:  person

{
  "changeSet":  {
    "id":  "modifyDataType-example",
    "author":  "liquibase-docs",
    "changes":  [{
      "modifyDataType":  {
        "catalogName":  "cat",
        "columnName":  "id",
        "newDataType":  "int",
        "schemaName":  "public",
        "tableName":  "person"
      }
    }]
  }
}

ALTER  TABLE  cat.person  MODIFY  id  INT;