package liquibase.sqlgenerator.core;

 import liquibase.database.Database;

 import liquibase.database.core.PostgresDatabase;

 import liquibase.exception.ValidationErrors;

 import liquibase.sql.Sql;

 import liquibase.sql.UnparsedSql;

 import liquibase.sqlgenerator.SqlGenerator;

 import liquibase.sqlgenerator.SqlGeneratorChain;

 import liquibase.statement.core.DropSequenceStatement;

 public class DropSequenceGenerator extends AbstractSqlGenerator<DropSequenceStatement> {

     @Override

     public boolean supports(DropSequenceStatement statement, Database database) {

         return database.supportsSequences();

     }

     public ValidationErrors validate(DropSequenceStatement dropSequenceStatement, Database database,

             SqlGeneratorChain sqlGeneratorChain) {

         ValidationErrors validationErrors = new ValidationErrors();

         validationErrors.checkRequiredField("sequenceName", dropSequenceStatement.getSequenceName());

         return validationErrors;

     }

     public Sql[] generateSql(DropSequenceStatement statement, Database database, SqlGeneratorChain sqlGeneratorChain) {

         String sql = "DROP SEQUENCE "

                 + database.escapeSequenceName(statement.getSchemaName(), statement.getSequenceName());

         if (database instanceof PostgresDatabase) {

             sql += " CASCADE";

         }

         return new Sql[] { new UnparsedSql(sql) };

     }

 }