package liquibase.change.custom;

 import liquibase.database.Database;

 import liquibase.exception.CustomChangeException;

 import liquibase.statement.SqlStatement;

 /**

  * Interface to implement when creating a custom change that generates SQL. When updating a database, implementing this

  * interface is preferred over CustomTaskChange because the SQL can either be executed directly or saved to a text file

  * for later use depending on the migration mode used. To allow the change to be rolled back, also implement the

  * CustomSqlRollback interface. If your change requires sql-based logic and non-sql-based logic, it is best to create a

  * change set that contains a mix of CustomSqlChange and CustomTaskChange calls.

  * 

  * @see liquibase.change.custom.CustomSqlRollback

  * @see liquibase.change.custom.CustomTaskChange

  */

 public interface CustomSqlChange extends CustomChange {

     /**

      * Generates the SQL statements required to run the change

      * 

      * @param database

      *            the target {@link liquibase.database.Database} associated to this change's statements

      * @return an array of {@link SqlStatement}s with the statements

      * @throws liquibase.exception.CustomChangeException

      *             if an exception occurs while processing this change

      * @throws liquibase.exception.UnsupportedChangeException

      *             if this change is not supported by the {@link liquibase.database.Database} passed as argument

      */

     public SqlStatement[] generateStatements(Database database) throws CustomChangeException;

 }