/*
* 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.ExtTypeInfoNumeric;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
/**
* Functions for {@link org.h2.engine.Mode.ModeEnum#DB2} and
* {@link org.h2.engine.Mode.ModeEnum#Derby} compatibility modes.
*/
public final class FunctionsDB2Derby extends ModeFunction {
private static final int IDENTITY_VAL_LOCAL = 5001;
private static final HashMap<String, FunctionInfo> FUNCTIONS = new HashMap<>();
private static final TypeInfo IDENTITY_VAL_LOCAL_TYPE = TypeInfo.getTypeInfo(Value.NUMERIC, 31, 0,
ExtTypeInfoNumeric.DECIMAL);
static {
FUNCTIONS.put("IDENTITY_VAL_LOCAL",
new FunctionInfo("IDENTITY_VAL_LOCAL", IDENTITY_VAL_LOCAL, 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 FunctionsDB2Derby getFunction(String upperName) {
FunctionInfo info = FUNCTIONS.get(upperName);
return info != null ? new FunctionsDB2Derby(info) : null;
}
private FunctionsDB2Derby(FunctionInfo info) {
super(info);
}
@Override
public Value getValue(SessionLocal session) {
switch (info.type) {
case IDENTITY_VAL_LOCAL:
return session.getLastIdentity().convertTo(type);
default:
throw DbException.getInternalError("type=" + info.type);
}
}
@Override
public Expression optimize(SessionLocal session) {
switch (info.type) {
case IDENTITY_VAL_LOCAL:
type = IDENTITY_VAL_LOCAL_TYPE;
break;
default:
throw DbException.getInternalError("type=" + info.type);
}
return this;
}
}