/*
* 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.
*/
package org.apache.empire.db.expr.column;
import org.apache.empire.data.DataType;
import org.apache.empire.db.DBColumnExpr;
import org.apache.empire.db.DBDatabaseDriver;
/**
* This class is used to convert a value to a different data type.
* This function uses the DBDatabaseDriver.getConvertPhrase function to obtain a conversion template.
* <P>
* There is no need to explicitly create instances of this class.<BR>
* Instead use {@link DBColumnExpr#convertTo(DataType) }
* <P>
* @author doebele
*/
public class DBConvertExpr extends DBAbstractFuncExpr
{
private final Object format;
/**
* Constructs a DBDecodeExpr
* @param expr the expression to be converted
* @param dataType the target data type
* @param format optional formatting information
*/
public DBConvertExpr(DBColumnExpr expr, DataType dataType, Object format)
{
super(expr, expr.getUpdateColumn(), false, dataType);
// Save Info
this.format = format;
}
@Override
protected String getFunctionName()
{
return "convert";
}
@Override
public void addSQL(StringBuilder sql, long context)
{
DBDatabaseDriver driver = getDatabaseDriver();
// Set Params
String template = driver.getConvertPhrase(dataType, expr.getDataType(), format);
super.addSQL(sql, template, null, context);
}
}