/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.translator.jdbc.db2;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import org.teiid.language.*;
import org.teiid.language.Comparison.Operator;
import org.teiid.language.Join.JoinType;
import org.teiid.translator.ExecutionContext;
import org.teiid.translator.SourceSystemFunctions;
import org.teiid.translator.TranslatorException;
import org.teiid.translator.TypeFacility;
import org.teiid.translator.jdbc.AliasModifier;
import org.teiid.translator.jdbc.ConvertModifier;
import org.teiid.translator.jdbc.FunctionModifier;
import org.teiid.translator.jdbc.JDBCExecutionFactory;
import org.teiid.translator.jdbc.LocateFunctionModifier;
import org.teiid.translator.jdbc.ModFunctionModifier;
public class BaseDB2ExecutionFactory extends JDBCExecutionFactory {
private final class NullHandlingFormatModifier extends
ConvertModifier.FormatModifier {
private NullHandlingFormatModifier(String alias) {
super(alias);
}
@Override
public List<?> translate(Function function) {
Expression arg = function.getParameters().get(0);
if (arg instanceof Literal && ((Literal)arg).getValue() == null) {
((Literal)function.getParameters().get(1)).setValue(this.alias);
return null;
}
return super.translate(function);
}
}
@Override
public void start() throws TranslatorException {
super.start();
registerFunctionModifier(SourceSystemFunctions.CHAR, new AliasModifier("chr")); //$NON-NLS-1$
registerFunctionModifier(SourceSystemFunctions.DAYOFMONTH, new AliasModifier("day")); //$NON-NLS-1$
registerFunctionModifier(SourceSystemFunctions.IFNULL, new AliasModifier("coalesce")); //$NON-NLS-1$
registerFunctionModifier(SourceSystemFunctions.LOCATE, new LocateFunctionModifier(getLanguageFactory()));
registerFunctionModifier(SourceSystemFunctions.SUBSTRING, new SubstringFunctionModifier());
registerFunctionModifier(SourceSystemFunctions.MOD, new ModFunctionModifier("MOD", getLanguageFactory())); //$NON-NLS-1$
//add in type conversion
ConvertModifier convertModifier = new ConvertModifier();
convertModifier.addTypeMapping("real", FunctionModifier.FLOAT); //$NON-NLS-1$
convertModifier.addTypeMapping("numeric(31,0)", FunctionModifier.BIGINTEGER); //$NON-NLS-1$
convertModifier.addTypeMapping("numeric(31,12)", FunctionModifier.BIGDECIMAL); //$NON-NLS-1$
convertModifier.addTypeMapping("char(1)", FunctionModifier.CHAR); //$NON-NLS-1$
convertModifier.addTypeMapping("blob", FunctionModifier.BLOB, FunctionModifier.OBJECT); //$NON-NLS-1$
convertModifier.addTypeMapping("clob", FunctionModifier.CLOB, FunctionModifier.XML); //$NON-NLS-1$
convertModifier.addConvert(FunctionModifier.TIME, FunctionModifier.TIMESTAMP, new FunctionModifier() {
@Override
public List<?> translate(Function function) {
return Arrays.asList("timestamp('1970-01-01', ", function.getParameters().get(0), ")"); //$NON-NLS-1$ //$NON-NLS-2$
}
});
convertModifier.addConvert(FunctionModifier.DATE, FunctionModifier.TIMESTAMP, new FunctionModifier() {
@Override
public List<?> translate(Function function) {
return Arrays.asList("timestamp(",function.getParameters().get(0), ", '00:00:00')"); //$NON-NLS-1$ //$NON-NLS-2$
}
});
//the next convert is not strictly necessary for db2, but it also works for derby
convertModifier.addConvert(FunctionModifier.STRING, FunctionModifier.FLOAT, new FunctionModifier() {
@Override
public List<?> translate(Function function) {
return Arrays.asList("cast(double(", function.getParameters().get(0), ") as real)"); //$NON-NLS-1$ //$NON-NLS-2$
}
});
convertModifier.addTypeConversion(new NullHandlingFormatModifier("varchar"), FunctionModifier.STRING); //$NON-NLS-1$
convertModifier.addTypeConversion(new NullHandlingFormatModifier("smallint"), FunctionModifier.BYTE, FunctionModifier.SHORT); //$NON-NLS-1$
convertModifier.addTypeConversion(new NullHandlingFormatModifier("integer"), FunctionModifier.INTEGER); //$NON-NLS-1$
convertModifier.addTypeConversion(new NullHandlingFormatModifier("bigint"), FunctionModifier.LONG); //$NON-NLS-1$
convertModifier.addTypeConversion(new NullHandlingFormatModifier("double"), FunctionModifier.DOUBLE); //$NON-NLS-1$
convertModifier.addTypeConversion(new NullHandlingFormatModifier("date"), FunctionModifier.DATE); //$NON-NLS-1$
convertModifier.addTypeConversion(new NullHandlingFormatModifier("time"), FunctionModifier.TIME); //$NON-NLS-1$
convertModifier.addTypeConversion(new NullHandlingFormatModifier("timestamp"), FunctionModifier.TIMESTAMP); //$NON-NLS-1$
convertModifier.addNumericBooleanConversions();
registerFunctionModifier(SourceSystemFunctions.CONVERT, convertModifier);
}
@SuppressWarnings("unchecked")
@Override
public List<?> translateLimit(Limit limit, ExecutionContext context) {
return Arrays.asList("FETCH FIRST ", limit.getRowLimit(), " ROWS ONLY"); //$NON-NLS-1$ //$NON-NLS-2$
}
@Override
public List<?> translate(LanguageObject obj, ExecutionContext context) {
//DB2 doesn't support cross join
convertCrossJoinToInner(obj, getLanguageFactory());
//DB2 needs projected nulls wrapped in casts
if (obj instanceof DerivedColumn) {
DerivedColumn selectSymbol = (DerivedColumn)obj;
if (selectSymbol.getExpression() instanceof Literal) {
Literal literal = (Literal)selectSymbol.getExpression();
if (literal.getValue() == null) {
String type = TypeFacility.RUNTIME_NAMES.INTEGER;
if (literal.getType() != TypeFacility.RUNTIME_TYPES.NULL) {
type = TypeFacility.getDataTypeName(literal.getType());
}
selectSymbol.setExpression(ConvertModifier.createConvertFunction(getLanguageFactory(), literal, type));
}
}
}
return super.translate(obj, context);
}
public static void convertCrossJoinToInner(LanguageObject obj, LanguageFactory lf) {
if (obj instanceof Join) {
Join join = (Join)obj;
if (join.getJoinType() == JoinType.CROSS_JOIN) {
Literal one = lf.createLiteral(1, TypeFacility.RUNTIME_TYPES.INTEGER);
join.setCondition(lf.createCompareCriteria(Operator.EQ, one, one));
join.setJoinType(JoinType.INNER_JOIN);
}
}
}
@Override
public NullOrder getDefaultNullOrder() {
return NullOrder.HIGH;
}
@Override
public boolean supportsInlineViews() {
return true;
}
@Override
public boolean supportsExcept() {
return true;
}
@Override
public boolean supportsIntersect() {
return true;
}
@Override
public boolean supportsSubqueryInOn() {
return false;
}
@Override
public boolean supportsSelectWithoutFrom() {
return true;
}
@Override
public List<?> translateCommand(Command command, ExecutionContext context) {
if (command instanceof Select) {
Select select = (Select)command;
if (select.getFrom() == null || select.getFrom().isEmpty()) {
List<Object> result = new ArrayList<Object>();
result.add("VALUES("); //$NON-NLS-1$
for (int i = 0; i < select.getDerivedColumns().size(); i++) {
DerivedColumn dc = select.getDerivedColumns().get(i);
if (i != 0) {
result.add(", "); //$NON-NLS-1$
}
result.add(dc.getExpression());
}
result.add(")"); //$NON-NLS-1$
return result;
}
}
return super.translateCommand(command, context);
}
}