package liquibase.change.core;

 import liquibase.change.AbstractChange;

 import liquibase.change.ChangeMetaData;

 import liquibase.database.Database;

 import liquibase.database.core.SQLiteDatabase;

 import liquibase.statement.SqlStatement;

 import liquibase.statement.core.DropForeignKeyConstraintStatement;

 /**

  * Drops an existing foreign key constraint.

  */

 public class DropForeignKeyConstraintChange extends AbstractChange {

     private String baseTableSchemaName;

     private String baseTableName;

     private String constraintName;

     public DropForeignKeyConstraintChange() {

         super("dropForeignKeyConstraint", "Drop Foreign Key Constraint", ChangeMetaData.PRIORITY_DEFAULT);

     }

     public String getBaseTableSchemaName() {

         return baseTableSchemaName;

     }

     public void setBaseTableSchemaName(String baseTableSchemaName) {

         this.baseTableSchemaName = baseTableSchemaName;

     }

     public String getBaseTableName() {

         return baseTableName;

     }

     public void setBaseTableName(String baseTableName) {

         this.baseTableName = baseTableName;

     }

     public String getConstraintName() {

         return constraintName;

     }

     public void setConstraintName(String constraintName) {

         this.constraintName = constraintName;

     }

     public SqlStatement[] generateStatements(Database database) {

         if (database instanceof SQLiteDatabase) {

             // return special statements for SQLite databases

             return generateStatementsForSQLiteDatabase(database);

         }

         return new SqlStatement[] { new DropForeignKeyConstraintStatement(

                 getBaseTableSchemaName() == null ? database.getDefaultSchemaName() : getBaseTableSchemaName(),

                 getBaseTableName(), getConstraintName()), };

     }

     private SqlStatement[] generateStatementsForSQLiteDatabase(Database database) {

         // SQLite does not support foreign keys until now.

         // See for more information: http://www.sqlite.org/omitted.html

         // Therefore this is an empty operation...

         return new SqlStatement[] {};

     }

     public String getConfirmationMessage() {

         return "Foreign key " + getConstraintName() + " dropped";

     }

 }