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* 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
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* KIND, either express or implied. See the License for the
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package org.apache.cayenne.dba.derby;
import java.io.IOException;
import java.sql.Types;
import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.access.translator.select.QueryAssembler;
import org.apache.cayenne.access.translator.select.TrimmingQualifierTranslator;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.exp.parser.ASTEqual;
import org.apache.cayenne.exp.parser.ASTExtract;
import org.apache.cayenne.exp.parser.ASTFunctionCall;
import org.apache.cayenne.exp.parser.ASTNotEqual;
import org.apache.cayenne.exp.parser.SimpleNode;
import org.apache.cayenne.map.DbAttribute;
public class DerbyQualifierTranslator extends TrimmingQualifierTranslator {
public DerbyQualifierTranslator(QueryAssembler queryAssembler, String trimFunction) {
super(queryAssembler, trimFunction);
}
@Override
protected void processColumnWithQuoteSqlIdentifiers(DbAttribute dbAttr, Expression pathExp) {
SimpleNode parent = null;
if (pathExp instanceof SimpleNode) {
parent = (SimpleNode) ((SimpleNode) pathExp).jjtGetParent();
}
// problem in derby : Comparisons between 'CLOB (UCS_BASIC)' and 'CLOB
// (UCS_BASIC)' 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(").append(size).append("))");
} else {
super.processColumnWithQuoteSqlIdentifiers(dbAttr, pathExp);
}
}
/**
* @since 4.0
*/
@Override
protected void appendFunction(ASTFunctionCall functionExpression) {
if("SUBSTRING".equals(functionExpression.getFunctionName())) {
out.append("SUBSTR");
} else if("CONCAT".equals(functionExpression.getFunctionName())) {
out.append("");
} else {
super.appendFunction(functionExpression);
}
}
/**
* A little bit ugly code that wraps String scalars to CAST(? AS VARCHAR(length))
* because otherwise derby don't know what type will be at the placeholder and
* use LONG VARCHAR that isn't comparable what leads to statement preparation failure.
*
* @since 4.0
*/
protected void appendFunctionArg(Object value, ASTFunctionCall functionExpression) throws IOException {
if("CONCAT".equals(functionExpression.getFunctionName())) {
if(value instanceof String) {
out.append("CAST(");
}
super.appendFunctionArg(value, functionExpression);
if(value instanceof String) {
clearLastFunctionArgDivider(functionExpression);
out.append(" AS VARCHAR(").append(((String)value).length()).append("))");
appendFunctionArgDivider(functionExpression);
}
} else {
super.appendFunctionArg(value, functionExpression);
}
}
/**
* @since 4.0
*/
@Override
protected void appendFunctionArgDivider(ASTFunctionCall functionExpression) {
if("CONCAT".equals(functionExpression.getFunctionName())) {
out.append(" || ");
} else {
super.appendFunctionArgDivider(functionExpression);
}
}
/**
* @since 4.0
*/
@Override
protected void clearLastFunctionArgDivider(ASTFunctionCall functionExpression) {
if("CONCAT".equals(functionExpression.getFunctionName())) {
out.delete(out.length() - 4, out.length());
} else {
super.clearLastFunctionArgDivider(functionExpression);
}
}
@Override
protected void appendExtractFunction(ASTExtract functionExpression) {
switch (functionExpression.getPart()) {
case DAY_OF_MONTH:
out.append("DAY");
break;
case DAY_OF_WEEK:
case DAY_OF_YEAR:
case WEEK:
throw new CayenneRuntimeException("Function %s() is unsupported in Derby."
, functionExpression.getPartCamelCaseName());
default:
super.appendExtractFunction(functionExpression);
}
}
}