/**
* Redistribution and use of this software and associated documentation
* ("Software"), with or without modification, are permitted provided
* that the following conditions are met:
*
* 1. Redistributions of source code must retain copyright
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* copy of this document.
*
* 2. Redistributions in binary form must reproduce the
* above copyright notice, this list of conditions and the
* following disclaimer in the documentation and/or other
* materials provided with the distribution.
*
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* products derived from this Software without prior written
* permission of Intalio, Inc. For written permission,
* please contact info@exolab.org.
*
* 4. Products derived from this Software may not be called "Exolab"
* nor may "Exolab" appear in their names without prior written
* permission of Intalio, Inc. Exolab is a registered
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*
* 5. Due credit should be given to the Exolab Project
* (http://www.exolab.org/).
*
* THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
* NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
* INTALIO, INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*
* Copyright 1999 (C) Intalio, Inc. All Rights Reserved.
*
* $Id$
*/
package org.exolab.castor.persist.spi;
import org.exolab.castor.jdo.DbMetaInfo;
import org.exolab.castor.jdo.QueryException;
import org.exolab.castor.jdo.oql.SyntaxNotSupportedException;
/**
* Defines the interface for a query expression. The query
* expression object is used to construct queries including
* parameters, conditions and joins, and generates the SQL
* statement for the underlying database.
* <p>
* A query experession object is created for each unique
* query, populated with the query parameters and the
* SQL statement is obtained from it at the proper time.
* <p>
* A query expression is generated from {@link PersistenceFactory},
* see this interface for information on how to configure
* it. The operators defined in this interface are part of
* SQL 92 and the supported OQL syntax and are expected to
* be supported by all query expressions.
*
* @author <a href="arkin@intalio.com">Assaf Arkin</a>
* @version $Revision$ $Date: 2005-03-05 06:42:06 -0700 (Sat, 05 Mar 2005) $
*/
public interface QueryExpression {
/** Equality operator. (<tt>=</tt>) */
String OP_EQUALS = "=";
/** Inequality operator. (<tt><></tt>) */
String OP_NOT_EQUALS = "<>";
/** Greater then operator. (<tt>></tt>) */
String OP_GREATER = ">";
/** Greater then or equals operator. (<tt>>=</tt>) */
String OP_GREATER_EQUALS = ">=";
/** Less then operator. (<tt><</tt>) */
String OP_LESS = "<";
/** Less then or equals operator. (<tt><=</tt>) */
String OP_LESS_EQUALS = "<=";
/** Like operator. (<tt>LIKE</tt>) */
String OP_LIKE = " LIKE ";
/** Not like operator. (<tt>NOT LIKE</tt>) */
String OP_NOT_LIKE = " NOT LIKE ";
/** Between operator. (<tt>BETWEEN</tt>) */
String OP_BETWEEN = " BETWEEN ";
/** Between and operator. (<tt>AND</tt>) */
String OP_BETWEEN_AND = " AND ";
/**
* Add a column used in the query. Columns must be retrieved in
* the same order in which they were added to the query.
*
* @param tableName The table name
* @param columnName The column name
*/
void addColumn(String tableName, String columnName);
/**
* Add an entire select clause to the query with one call. The caller is
* responsible for making sure that all mentioned tables are included in
* the from clause.
*
* @param selectClause The entire sql select clause without the word SELECT
*/
void addSelect(String selectClause);
/**
* Set the query to be distinct. No two rows which are the same will be returned.
*
* @param distinct If the query should include DISTINCT in the SQL select.
*/
void setDistinct(boolean distinct);
/**
* Add a table with an alias to the from clause.
*
* @param tableName The name of the table to add to the select clause
* @param tableAlias The name of the alias under which the where clauses will access it
*/
void addTable(String tableName, String tableAlias);
/**
* Add a query paramater.
*
* @param tableName The table name
* @param columnName The column name
* @param condOp The conditional operation
*/
void addParameter(String tableName, String columnName, String condOp);
/**
* Add a condition.
*
* @param tableName The table name
* @param columnName The column name
* @param condOp The conditional operation
* @param value The conditional value
*/
void addCondition(String tableName, String columnName, String condOp, String value);
/**
* Encode a TableColumn for use in expressions.
*
* @param tableName The table name.
* @param columnName The column name.
*/
String encodeColumn(String tableName, String columnName);
/**
* Adds a where clause. Caller is responsible for making sure all tables
* mentioned in the where clause are included in the fromClause.
*
* @param whereClause The WHERE clause to add (without the word WHERE).
*/
void addWhereClause(String whereClause);
/**
* Adds an order by clause. Caller is responsible for making sure all
* tables mentioned in the order by clause are included in the fromClause.
*
* @param orderClause The ORDER BY clause to add (without the words ORDER BY).
*/
void addOrderClause(String orderClause);
/**
* Adds an limit clause.
*
* @param limitClause The LIMIT clause to add (without the word LIMIT).
* @throws SyntaxNotSupportedException If the LIMIT clause is not supported by the RDBMS.
*/
void addLimitClause(String limitClause) throws SyntaxNotSupportedException;
/**
* Adds an offset clause.
*
* @param offsetClause The OFFSET clause to add (without the word OFFSET).
* @throws SyntaxNotSupportedException If the OFFSET clause is not supported by the RDBMS.
*/
void addOffsetClause(String offsetClause) throws SyntaxNotSupportedException;
/**
* Add an inner join with an aliases for the tables.
*
* @param leftTable The table name on the left side
* @param leftColumn The column names on the left side
* @param leftTableAlias The alias name to use for the table on the left side
* @param rightTable The table name on the right side
* @param rightColumn The column names on the right side
* @param rightTableAlias The alias name to use for the table on the right side
*/
void addInnerJoin(String leftTable, String[] leftColumn, String leftTableAlias,
String rightTable, String[] rightColumn, String rightTableAlias);
/**
* Add an outer join. May use an inner join if outer
* joins are not supported.
*
* @param leftTable The table name on the left side
* @param leftColumn The column name on the left side
* @param rightTable The table name on the right side
* @param rightColumn The column name on the right side
* @param rightTableAlias The alias name to use for the table on the right side
*/
void addOuterJoin(String leftTable, String[] leftColumn,
String rightTable, String[] rightColumn, String rightTableAlias);
/**
* Return the query expression as an SQL statement. The resulting
* SQL is fed directly to a JDBC statement. <tt>writeLock</tt> is
* true if the query must obtain a write lock on the queried table.
*
* @param writeLock True if a write lock is required
* @return The SQL statement
* @throws QueryException The query cannot be constructed for
* this engine
*/
String getStatement(boolean writeLock) throws QueryException;
/**
* Returns a clone of the query expression that can be further modified.
*/
Object clone();
/**
* Indicates whether a RDBMS supports LIMIT clauses.
*
* @return True if a LIMIT clause is supported.
*/
boolean isLimitClauseSupported();
/**
* Indicates whether a RDBMS supports OFFSET clauses.
*
* @return True if an OFFSET clause is supported.
*/
boolean isOffsetClauseSupported();
/**
* Store database meta information.
*
* @param dbInfo DbMetaInfo instance
*/
void setDbMetaInfo(DbMetaInfo dbInfo);
}