org.apache.openjpa.jdbc.kernel.exps.SQLEmbed 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 org.apache.openjpa.jdbc.kernel.JDBCStore;
import org.apache.openjpa.jdbc.meta.ClassMapping;
import org.apache.openjpa.jdbc.sql.SQLBuffer;
import org.apache.openjpa.kernel.StoreContext;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.util.UnsupportedException;
import org.apache.openjpa.util.UserException;
/**
* Simple listener which embeds its SQL argument into the query. Listens
* on sql.
* Example:
* "price < sql(\"(SELECT AVG (PRICE) FROM PRODUCT_TABLE)\")"
*
*/
public class SQLEmbed
implements JDBCFilterListener {
public static String TAG = "sql";
private static final Localizer _loc = Localizer.forPackage(SQLEmbed.class);
public String getTag() {
return TAG;
}
public boolean expectsArguments() {
return true;
}
public boolean expectsTarget() {
return false;
}
public Object evaluate(Object target, Class targetClass, Object[] args,
Class[] argClasses, Object candidate, StoreContext ctx) {
throw new UnsupportedException(_loc.get("no-in-mem", TAG));
}
public void appendTo(SQLBuffer buf, FilterValue target, FilterValue[] args,
ClassMapping type, JDBCStore store) {
if (!args[0].isConstant())
throw new UserException(_loc.get("const-only", TAG));
buf.append(args[0].getValue().toString());
}
public Class getType(Class targetClass, Class[] argClasses) {
return Object.class;
}
}