db_alias.java

derby database source code.good for you.

/*

   Derby - Class org.apache.derby.impl.tools.dblook.DB_Alias

   Copyright 2004 The Apache Software Foundation or its licensors, as applicable.

   Licensed 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.

 */

package org.apache.derby.impl.tools.dblook;

import java.sql.Connection;
import java.sql.Statement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.DatabaseMetaData;

import java.util.HashMap;
import org.apache.derby.tools.dblook;

public class DB_Alias {

	// Prepared statements use throughout the DDL
	// generation process.

	/* ************************************************
	 * Generate the DDL for all stored procedures and
	 * functions in a given database and write it to
	 * output via Logs.java.
	 * @param conn Connection to the source database.
	 ****/

	public static void doProceduresAndFunctions(Connection conn)
		throws SQLException {

		// First do stored procedures.
		Statement stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery("SELECT ALIAS, ALIASINFO, " +
			"ALIASID, SCHEMAID, JAVACLASSNAME, SYSTEMALIAS FROM SYS.SYSALIASES " +
			"WHERE ALIASTYPE='P'");
		generateDDL(rs, 'P');	// 'P' => for PROCEDURES

		// Now do functions.
		rs = stmt.executeQuery("SELECT ALIAS, ALIASINFO, " +
			"ALIASID, SCHEMAID, JAVACLASSNAME, SYSTEMALIAS FROM SYS.SYSALIASES " +
			"WHERE ALIASTYPE='F'");
		generateDDL(rs, 'F');	// 'F' => for FUNCTIONS

		rs.close();
		stmt.close();
		return;

	}

	/* ************************************************
	 * Generate the DDL for either stored procedures or
	 * functions in a given database, depending on the
	 * the received aliasType.
	 * @param rs Result set holding either stored procedures
	 *  or functions.
	 * @param aliasType Indication of whether we're generating
	 *  stored procedures or functions.
	 ****/
	private static void generateDDL(ResultSet rs, char aliasType)
		throws SQLException
	{

		boolean firstTime = true;
		while (rs.next()) {

			if (rs.getBoolean(6))
			// it's a system alias, so we ignore it.
				continue;

			String procSchema = dblook.lookupSchemaId(rs.getString(4));
			if (dblook.isIgnorableSchema(procSchema))
				continue;

			if (firstTime) {
				Logs.reportString("----------------------------------------------");
				Logs.reportMessage((aliasType == 'P')
					? "DBLOOK_StoredProcHeader"
					: "DBLOOK_FunctionHeader");
				Logs.reportString("----------------------------------------------\n");
			}

			String aliasName = rs.getString(1);
			String fullName = dblook.addQuotes(
				dblook.expandDoubleQuotes(aliasName));
			fullName = procSchema + "." + fullName;

			String creationString = createProcOrFuncString(
				fullName, rs, aliasType);
			Logs.writeToNewDDL(creationString);
			Logs.writeStmtEndToNewDDL();
			Logs.writeNewlineToNewDDL();
			firstTime = false;

		}

	}

	/* ************************************************
	 * Generate DDL for a specific stored procedure or
	 * function.
	 * @param aliasName Name of the current procedure/function
	 * @param aliasInfo Info about the current procedure/function
	 * @param aliasType Indicator of whether we're generating
	 *  a stored procedure or a function.
	 * @return DDL for the current stored procedure is
	 *   returned, as a String.
	 ****/

	private static String createProcOrFuncString(String aliasName,
		ResultSet aliasInfo, char aliasType) throws SQLException
	{

		StringBuffer alias = new StringBuffer("CREATE ");
		if (aliasType == 'P')
			alias.append("PROCEDURE ");
		else if (aliasType == 'F')
			alias.append("FUNCTION ");
		alias.append(aliasName);
		alias.append(" ");

		String params = aliasInfo.getString(2);

		// Just grab the parameter part; we'll get the method name later.
		alias.append(params.substring(params.indexOf("("), params.length()));
		alias.append(" ");

		// Now add the external name.
		alias.append("EXTERNAL NAME '");
		alias.append(aliasInfo.getString(5));
		alias.append(".");
		// Get method name from parameter string fetched above.
		alias.append(params.substring(0, params.indexOf("(")));
		alias.append("' ");

		return alias.toString();

	}

	/* ************************************************
	 * Generate the DDL for all synonyms in a given
	 * database. On successul return, the DDL for the
	 * synonyms has been written to output via Logs.java.
	 * @param conn Connection to the source database.
	 * @return 
	 ****/
	public static void doSynonyms(Connection conn) throws SQLException
	{
		Statement stmt = conn.createStatement();
		ResultSet rs = stmt.executeQuery("SELECT ALIAS, SCHEMAID, " +
			"ALIASINFO, SYSTEMALIAS FROM SYS.SYSALIASES A WHERE ALIASTYPE='S'");

		boolean firstTime = true;
		while (rs.next()) {
			if (rs.getBoolean(4))
			// it's a system alias, so we ignore it.
				continue;

			String aliasSchema = dblook.lookupSchemaId(rs.getString(2));
			if (dblook.isIgnorableSchema(aliasSchema))
				continue;

			if (firstTime) {
				Logs.reportString("----------------------------------------------");
				Logs.reportMessage("DBLOOK_SynonymHeader");
				Logs.reportString("----------------------------------------------\n");
			}

			String aliasName = rs.getString(1);
			String aliasFullName = dblook.addQuotes(
				dblook.expandDoubleQuotes(aliasName));
			aliasFullName = aliasSchema + "." + aliasFullName;

			Logs.writeToNewDDL("CREATE SYNONYM "+aliasFullName+" FOR "+rs.getString(3));
			Logs.writeStmtEndToNewDDL();
			Logs.writeNewlineToNewDDL();
			firstTime = false;
		}

		rs.close();
		stmt.close();
		return;

	}
}