/*
* 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 org.apache.openjpa.jdbc.meta.ClassMapping;
import org.apache.openjpa.jdbc.meta.FieldMapping;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.jdbc.sql.Select;
/**
* Compares two values.
*
* @author Abe White
*/
class EqualExpression
extends CompareEqualExpression {
/**
* Constructor. Supply values to compare.
*/
public EqualExpression(Val val1, Val val2) {
super(val1, val2);
}
public void appendTo(Select sel, ExpContext ctx, BinaryOpExpState bstate,
SQLBuffer buf, boolean val1Null, boolean val2Null) {
if (val1Null && val2Null)
buf.append("1 = 1");
else if (val1Null || val2Null) {
Val val = (val1Null) ? getValue2() : getValue1();
ExpState state = (val1Null) ? bstate.state2 : bstate.state1;
if (!isDirectComparison()) {
int len = val.length(sel, ctx, state);
for (int i = 0; i < len; i++) {
if (i > 0)
buf.append(" AND ");
val.appendTo(sel, ctx, state, buf, i);
buf.append(" IS ").appendValue(null);
}
} else
val.appendIsNull(sel, ctx, state, buf);
} else {
Val val1 = getValue1();
Val val2 = getValue2();
if (val1.length(sel, ctx, bstate.state1) == 1
&& val2.length(sel, ctx, bstate.state2) == 1) {
ctx.store.getDBDictionary().comparison(buf, "=",
new FilterValueImpl(sel, ctx, bstate.state1, val1),
new FilterValueImpl(sel, ctx, bstate.state2, val2));
} else {
int lenVal1 = val1.length(sel, ctx, bstate.state1);
int lenVal2 = val2.length(sel, ctx, bstate.state2);
int len = java.lang.Math.min(lenVal1, lenVal2);
// OPENJPA-2631: Detect and handle slightly differently the
// case where a composite PK is in use. When an equals comparison
// is created by CriteriaBuilder, and the comparison is done against
// an entity with a composite PK, 'val2' can be either a:
// 1) Lit - in this case a Lit is hard coded to return a length of 1.
// 2) Param - in this case the metadata is null so length will return 1.
// Given this, first look to see if lenVal1 is greater than lenVal2.
if (lenVal1 > lenVal2) {
// If here, lets get the metadata from val1 and see if its PK
// is an embeddable. If so, the length (val1Len) will be the
// size of the number of colunns in the PK. Use this length
// in order to create an equal expression with the right number
// of 'AND' statementes.
ClassMapping cm = (ClassMapping) val1.getMetaData();
FieldMapping[] fmsPK = cm.getPrimaryKeyFieldMappings();
if (fmsPK[0].isEmbedded()) {
len = lenVal1;
}
}
for (int i = 0; i < len; i++) {
if (i > 0)
buf.append(" AND ");
val1.appendTo(sel, ctx, bstate.state1, buf, i);
buf.append(" = ");
val2.appendTo(sel, ctx, bstate.state2, buf, i);
}
}
}
}
}