/*****************************************************************
* 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.cayenne.dba.db2;
import java.io.IOException;
import java.sql.Types;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.access.trans.QueryAssembler;
import org.apache.cayenne.access.trans.TrimmingQualifierTranslator;
import org.apache.cayenne.dba.TypesMapping;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.exp.parser.ASTEqual;
import org.apache.cayenne.exp.parser.ASTNotEqual;
import org.apache.cayenne.exp.parser.SimpleNode;
import org.apache.cayenne.map.DbAttribute;
/**
*/
public class DB2QualifierTranslator extends TrimmingQualifierTranslator {
public DB2QualifierTranslator(QueryAssembler queryAssembler, String trimFunction) {
super(queryAssembler, trimFunction);
}
@Override
protected void appendLiteralDirect(
Object val,
DbAttribute attr,
Expression parentExpression) throws IOException {
boolean castNeeded = false;
if (parentExpression != null) {
int type = parentExpression.getType();
castNeeded = attr != null
&& (type == Expression.LIKE
|| type == Expression.LIKE_IGNORE_CASE
|| type == Expression.NOT_LIKE || type == Expression.NOT_LIKE_IGNORE_CASE);
}
if (castNeeded) {
out.append("CAST (");
}
super.appendLiteralDirect(val, attr, parentExpression);
if (castNeeded) {
int jdbcType = attr.getType();
int len = attr.getMaxLength();
// determine CAST type
// LIKE on CHAR may produce unpredictible results
// LIKE on LONVARCHAR doesn't seem to be supported
if (jdbcType == Types.CHAR || jdbcType == Types.LONGVARCHAR) {
jdbcType = Types.VARCHAR;
// length is required for VARCHAR
if (len <= 0) {
len = 254;
}
}
out.append(" AS ");
String[] types = queryAssembler.getAdapter().externalTypesForJdbcType(
jdbcType);
if (types == null || types.length == 0) {
throw new CayenneRuntimeException(
"Can't find database type for JDBC type '"
+ TypesMapping.getSqlNameByType(jdbcType));
}
out.append(types[0]);
if (len > 0 && TypesMapping.supportsLength(jdbcType)) {
out.append("(");
out.append(String.valueOf(len));
out.append(")");
}
out.append(")");
}
}
@Override
protected void processColumnWithQuoteSqlIdentifiers(
DbAttribute dbAttr,
Expression pathExp) throws IOException {
SimpleNode parent = null;
if (pathExp instanceof SimpleNode) {
parent = (SimpleNode) ((SimpleNode) pathExp).jjtGetParent();
}
// problem in db2 : Comparisons between CLOB and CLOB are not supported.
// we need do it by casting the Clob to VARCHAR.
if (parent != null
&& (parent instanceof ASTEqual || parent instanceof ASTNotEqual)
&& dbAttr.getType() == Types.CLOB
&& parent.getOperandCount() == 2
&& parent.getOperand(1) instanceof String) {
Integer size = parent.getOperand(1).toString().length() + 1;
out.append("CAST(");
super.processColumnWithQuoteSqlIdentifiers(dbAttr, pathExp);
out.append(" AS VARCHAR(" + size + "))");
}
else {
super.processColumnWithQuoteSqlIdentifiers(dbAttr, pathExp);
}
}
}