public String dropIndex(Index index, boolean quoteIdentifiers, boolean qualifyNames) {
   return DROP
       + SPACE
       + INDEX
       + SPACE
       + getName(index.getTable(), quoteIdentifiers, qualifyNames)
       + DOT
       + getName(index, quoteIdentifiers, false)
       + NEWLINE;
 }
 public String dropTableConstraint(
     Index uniqueIndex, boolean quoteIdentifiers, boolean qualifyNames) {
   return ALTER
       + SPACE
       + TABLE
       + SPACE
       + getName(uniqueIndex.getTable(), quoteIdentifiers, qualifyNames)
       + " DROP CONSTRAINT "
       + getName(uniqueIndex, quoteIdentifiers, false)
       + NEWLINE; //$NON-NLS-1$
 }
  public String addUniqueConstraint(
      Index constraint, boolean quoteIdentifiers, boolean qualifyNames) {
    String statement =
        ALTER
            + SPACE
            + TABLE
            + SPACE
            + getName(constraint.getTable(), quoteIdentifiers, qualifyNames)
            + SPACE;
    statement += this.getAddUniqueConstraintClause(constraint, quoteIdentifiers);

    return statement + NEWLINE;
  }
  public String createIndex(Index index, boolean quoteIdentifiers, boolean qualifyNames) {
    String statement = CREATE + SPACE;
    if (index.isUnique()) {
      statement += UNIQUE + SPACE;
    }
    statement +=
        INDEX
            + SPACE
            + getName(index, quoteIdentifiers, false)
            + SPACE
            + ON
            + SPACE
            + getName(index.getTable(), quoteIdentifiers, qualifyNames)
            + SPACE
            + LEFT_PARENTHESIS
            + getIndexKeyColumns(index, quoteIdentifiers)
            + RIGHT_PARENTHESIS;

    statement +=
        NEWLINE + WITH + SPACE + LEFT_PARENTHESIS + generateIndexOptions(index) + RIGHT_PARENTHESIS;

    return statement + NEWLINE;
  }
  public String addForeignKey(
      ForeignKey foreignKey, boolean quoteIdentifiers, boolean qualifyNames) {
    UniqueConstraint uniqueConstraint = foreignKey.getUniqueConstraint();
    Index index = foreignKey.getUniqueIndex();
    Table parentTable = null;
    String parentKey = null;
    if (uniqueConstraint != null) {
      parentTable = uniqueConstraint.getBaseTable();
      parentKey = this.getKeyColumns(uniqueConstraint, quoteIdentifiers);
    } else if (index != null) {
      parentTable = index.getTable();
      parentKey = this.getParentKeyColumns(index, quoteIdentifiers);
    }
    if (parentTable == null) {
      this.getEngineeringCallBack()
          .writeMessage(
              MessageFormat.format(
                  GenericCatalogMessages.FE_PARENT_TABLLE_OR_KEY_DO_NOT_EXIST,
                  new Object[] {foreignKey.getName()}));
      return null;
    }

    String statement =
        ALTER
            + SPACE
            + TABLE
            + SPACE
            + getName(foreignKey.getBaseTable(), quoteIdentifiers, qualifyNames)
            + SPACE
            + ADD
            + SPACE
            + CONSTRAINT
            + SPACE
            + getName(foreignKey, quoteIdentifiers)
            + SPACE
            + FOREIGN_KEY
            + SPACE
            + LEFT_PARENTHESIS
            + this.getKeyColumns(foreignKey, quoteIdentifiers)
            + RIGHT_PARENTHESIS
            + NEWLINE;
    statement +=
        TAB
            + REFERENCES
            + SPACE
            + getName(parentTable, quoteIdentifiers, qualifyNames)
            + SPACE
            + LEFT_PARENTHESIS
            + parentKey
            + RIGHT_PARENTHESIS;

    ReferentialActionType action = foreignKey.getOnDelete();
    if (action != ReferentialActionType.RESTRICT_LITERAL
        && action != ReferentialActionType.NO_ACTION_LITERAL) {
      statement += NEWLINE + TAB + ON + SPACE + DELETE + SPACE;
      statement += getReferentialAction(action);
    }

    action = foreignKey.getOnUpdate();
    if (action != ReferentialActionType.RESTRICT_LITERAL
        && action != ReferentialActionType.NO_ACTION_LITERAL) {
      statement += NEWLINE + TAB + ON + SPACE + UPDATE + SPACE;
      statement += getReferentialAction(action);
    }

    if (foreignKey.isDeferrable()) {
      statement += NEWLINE + TAB + getDeferrableClause(foreignKey);
    }
    return statement + NEWLINE;
  }