org.apache.openjpa.jdbc.kernel.exps.IsNotEmptyExpression Maven / Gradle / Ivy
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* 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.openjpa.jdbc.kernel.exps;
import java.util.Map;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
import org.apache.openjpa.kernel.exps.ExpressionVisitor;
/**
* Tests whether the given value is not empty.
*
* @author Marc Prud'hommeaux
*/
class IsNotEmptyExpression
implements Exp {
private final Val _val;
/**
* Constructor. Supply value to test.
*/
public IsNotEmptyExpression(Val val) {
_val = val;
}
public ExpState initialize(Select sel, ExpContext ctx, Map contains) {
return _val.initialize(sel, ctx, Val.NULL_CMP);
}
public void appendTo(Select sel, ExpContext ctx, ExpState state,
SQLBuffer buf) {
_val.calculateValue(sel, ctx, state, null, null);
_val.appendIsNotEmpty(sel, ctx, state, buf);
sel.append(buf, state.joins);
}
public void selectColumns(Select sel, ExpContext ctx, ExpState state,
boolean pks) {
_val.selectColumns(sel, ctx, state, true);
}
public void acceptVisit(ExpressionVisitor visitor) {
visitor.enter(this);
_val.acceptVisit(visitor);
visitor.exit(this);
}
}