src/java/org/apache/ddlutils/platform/interbase/InterbaseBuilder.java

package org.apache.ddlutils.platform.interbase;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.io.IOException;
import java.sql.Types;
import java.util.Map;

import org.apache.ddlutils.Platform;
import org.apache.ddlutils.model.Column;
import org.apache.ddlutils.model.Database;
import org.apache.ddlutils.model.Index;
import org.apache.ddlutils.model.Table;
import org.apache.ddlutils.platform.SqlBuilder;
import org.apache.ddlutils.util.Jdbc3Utils;

/**
 * The SQL Builder for the Interbase database.
 * 
 * @version $Revision: 231306 $
 */
public class InterbaseBuilder extends SqlBuilder
{
    /**
     * Creates a new builder instance.
     * 
     * @param platform The plaftform this builder belongs to
     */
    public InterbaseBuilder(Platform platform)
    {
        super(platform);
        addEscapedCharSequence("'", "''");
    }

    /**
     * {@inheritDoc}
     */
    public void createTable(Database database, Table table, Map parameters) throws IOException
    {
        super.createTable(database, table, parameters);

        // creating generator and trigger for auto-increment
        Column[] columns = table.getAutoIncrementColumns();

        for (int idx = 0; idx < columns.length; idx++)
        {
            writeAutoIncrementCreateStmts(database, table, columns[idx]);
        }
    }

    /**
     * {@inheritDoc}
     */
    protected String getNativeDefaultValue(Column column)
    {
        if ((column.getTypeCode() == Types.BIT) ||
            (Jdbc3Utils.supportsJava14JdbcTypes() && (column.getTypeCode() == Jdbc3Utils.determineBooleanTypeCode())))
        {
            return getDefaultValueHelper().convert(column.getDefaultValue(), column.getTypeCode(), Types.SMALLINT).toString();
        }
        else
        {
            return super.getNativeDefaultValue(column);
        }
    }

    /**
     * {@inheritDoc}
     */
    public void dropTable(Table table) throws IOException
    {
        // dropping generators for auto-increment
        Column[] columns = table.getAutoIncrementColumns();

        for (int idx = 0; idx < columns.length; idx++)
        {
            writeAutoIncrementDropStmts(table, columns[idx]);
        }
        super.dropTable(table);
    }

    /**
     * {@inheritDoc}
     */
    public void dropIndex(Table table, Index index) throws IOException
    {
        // Index names in Interbase are unique to a schema and hence we do not
        // need the ON <tablename> clause
        print("DROP INDEX ");
        printIdentifier(getIndexName(index));
        printEndOfStatement();
    }

    /**
     * Writes the creation statements to make the given column an auto-increment column.
     * 
     * @param database The database model
     * @param table    The table
     * @param column   The column to make auto-increment
     */
    private void writeAutoIncrementCreateStmts(Database database, Table table, Column column) throws IOException
    {
        print("CREATE GENERATOR ");
        printIdentifier(getGeneratorName(table, column));
        printEndOfStatement();

        print("CREATE TRIGGER ");
        printIdentifier(getTriggerName(table, column));
        print(" FOR ");
        printlnIdentifier(getTableName(table));
        println("ACTIVE BEFORE INSERT POSITION 0 AS");
        print("BEGIN IF (NEW.");
        printIdentifier(getColumnName(column));
        print(" IS NULL) THEN NEW.");
        printIdentifier(getColumnName(column));
        print(" = GEN_ID(");
        printIdentifier(getGeneratorName(table, column));
        print(", 1); END");
        printEndOfStatement();
    }

    /**
     * Writes the statements to drop the auto-increment status for the given column.
     * 
     * @param table  The table
     * @param column The column to remove the auto-increment status for
     */
    private void writeAutoIncrementDropStmts(Table table, Column column) throws IOException
    {
        print("DROP TRIGGER ");
        printIdentifier(getTriggerName(table, column));
        printEndOfStatement();

        print("DROP GENERATOR ");
        printIdentifier(getGeneratorName(table, column));
        printEndOfStatement();
    }

    /**
     * Determines the name of the trigger for an auto-increment column.
     * 
     * @param table  The table
     * @param column The auto-increment column
     * @return The trigger name
     */
    protected String getTriggerName(Table table, Column column)
    {
        return getConstraintName("trg", table, column.getName(), null);
    }

    /**
     * Determines the name of the generator for an auto-increment column.
     * 
     * @param table  The table
     * @param column The auto-increment column
     * @return The generator name
     */
    protected String getGeneratorName(Table table, Column column)
    {
        return getConstraintName("gen", table, column.getName(), null);
    }

    /**
     * {@inheritDoc}
     */
    protected void writeColumnAutoIncrementStmt(Table table, Column column) throws IOException
    {
        // we're using a generator
    }

    /**
     * {@inheritDoc}
     */
    public String getSelectLastIdentityValues(Table table)
    {
        Column[] columns = table.getAutoIncrementColumns();

        if (columns.length == 0)
        {
            return null;
        }
        else
        {
            StringBuffer result = new StringBuffer();
    
            result.append("SELECT ");
            for (int idx = 0; idx < columns.length; idx++)
            {
                result.append("GEN_ID(");
                result.append(getDelimitedIdentifier(getGeneratorName(table, columns[idx])));
                result.append(", 0)");
            }
            result.append(" FROM RDB$DATABASE");
            return result.toString();
        }
    }

    /**
     * Writes the SQL to add/insert a column.
     * 
     * @param model      The database model
     * @param table      The table
     * @param newColumn  The new column
     * @param prevColumn The column after which the new column shall be added; <code>null</code>
     *                   if the new column is to be inserted at the beginning
     */
    public void insertColumn(Database model, Table table, Column newColumn, Column prevColumn) throws IOException
    {
        print("ALTER TABLE ");
        printlnIdentifier(getTableName(table));
        printIndent();
        print("ADD ");
        writeColumn(table, newColumn);
        printEndOfStatement();

        if (prevColumn != null)
        {
            // Even though Interbase can only add columns, we can move them later on
            print("ALTER TABLE ");
            printlnIdentifier(getTableName(table));
            printIndent();
            print("ALTER ");
            printIdentifier(getColumnName(newColumn));
            print(" POSITION ");
            // column positions start at 1 in Interbase
            print(String.valueOf(table.getColumnIndex(prevColumn) + 2));
            printEndOfStatement();
        }
        if (newColumn.isAutoIncrement())
        {
            writeAutoIncrementCreateStmts(model, table, newColumn);
        }
    }

    /**
     * Writes the SQL to drop a column.
     * 
     * @param table  The table
     * @param column The column to drop
     */
    public void dropColumn(Table table, Column column) throws IOException
    {
        if (column.isAutoIncrement())
        {
            writeAutoIncrementDropStmts(table, column);
        }
        print("ALTER TABLE ");
        printlnIdentifier(getTableName(table));
        printIndent();
        print("DROP ");
        printIdentifier(getColumnName(column));
        printEndOfStatement();
    }
}