/*
* Copyright 2004-2023 H2 Group. Multiple-Licensed under the MPL 2.0,
* and the EPL 1.0 (https://h2database.com/html/license.html).
* Initial Developer: H2 Group
*/
package org.h2.mode;
import java.util.HashMap;
import org.h2.engine.SessionLocal;
import org.h2.expression.Expression;
import org.h2.message.DbException;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
/**
* This class implements some legacy functions not available in Regular mode.
*/
public class FunctionsLegacy extends ModeFunction {
private static final HashMap<String, FunctionInfo> FUNCTIONS = new HashMap<>();
private static final int IDENTITY = 6001;
private static final int SCOPE_IDENTITY = IDENTITY + 1;
static {
FUNCTIONS.put("IDENTITY", new FunctionInfo("IDENTITY", IDENTITY, 0, Value.BIGINT, true, false));
FUNCTIONS.put("SCOPE_IDENTITY",
new FunctionInfo("SCOPE_IDENTITY", SCOPE_IDENTITY, 0, Value.BIGINT, true, false));
}
/**
* Returns mode-specific function for a given name, or {@code null}.
*
* @param upperName
* the upper-case name of a function
* @return the function with specified name or {@code null}
*/
public static FunctionsLegacy getFunction(String upperName) {
FunctionInfo info = FUNCTIONS.get(upperName);
if (info != null) {
return new FunctionsLegacy(info);
}
return null;
}
private FunctionsLegacy(FunctionInfo info) {
super(info);
}
@Override
public Value getValue(SessionLocal session) {
switch (info.type) {
case IDENTITY:
case SCOPE_IDENTITY:
return session.getLastIdentity().convertTo(type);
default:
throw DbException.getInternalError("type=" + info.type);
}
}
@Override
public Expression optimize(SessionLocal session) {
type = TypeInfo.getTypeInfo(info.returnDataType);
return this;
}
}