/*
* 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.api.ErrorCode;
import org.h2.engine.SessionLocal;
import org.h2.expression.Expression;
import org.h2.expression.ValueExpression;
import org.h2.expression.function.DateTimeFunction;
import org.h2.message.DbException;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
import org.h2.value.ValueNull;
import org.h2.value.ValueUuid;
/**
* Functions for {@link org.h2.engine.Mode.ModeEnum#Oracle} compatibility mode.
*/
public final class FunctionsOracle extends ModeFunction {
private static final int ADD_MONTHS = 2001;
private static final int SYS_GUID = ADD_MONTHS + 1;
private static final int TO_DATE = SYS_GUID + 1;
private static final int TO_TIMESTAMP = TO_DATE + 1;
private static final int TO_TIMESTAMP_TZ = TO_TIMESTAMP + 1;
private static final HashMap<String, FunctionInfo> FUNCTIONS = new HashMap<>();
static {
FUNCTIONS.put("ADD_MONTHS",
new FunctionInfo("ADD_MONTHS", ADD_MONTHS, 2, Value.TIMESTAMP, true, true));
FUNCTIONS.put("SYS_GUID",
new FunctionInfo("SYS_GUID", SYS_GUID, 0, Value.VARBINARY, false, false));
FUNCTIONS.put("TO_DATE",
new FunctionInfo("TO_DATE", TO_DATE, VAR_ARGS, Value.TIMESTAMP, true, true));
FUNCTIONS.put("TO_TIMESTAMP",
new FunctionInfo("TO_TIMESTAMP", TO_TIMESTAMP, VAR_ARGS, Value.TIMESTAMP, true, true));
FUNCTIONS.put("TO_TIMESTAMP_TZ",
new FunctionInfo("TO_TIMESTAMP_TZ", TO_TIMESTAMP_TZ, VAR_ARGS, Value.TIMESTAMP_TZ, true, true));
}
/**
* 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 FunctionsOracle getFunction(String upperName) {
FunctionInfo info = FUNCTIONS.get(upperName);
return info != null ? new FunctionsOracle(info) : null;
}
private FunctionsOracle(FunctionInfo info) {
super(info);
}
@Override
protected void checkParameterCount(int len) {
int min = 0, max = Integer.MAX_VALUE;
switch (info.type) {
case TO_TIMESTAMP:
case TO_TIMESTAMP_TZ:
min = 1;
max = 2;
break;
case TO_DATE:
min = 1;
max = 3;
break;
default:
throw DbException.getInternalError("type=" + info.type);
}
if (len < min || len > max) {
throw DbException.get(ErrorCode.INVALID_PARAMETER_COUNT_2, info.name, min + ".." + max);
}
}
@Override
public Expression optimize(SessionLocal session) {
boolean allConst = optimizeArguments(session);
switch (info.type) {
case SYS_GUID:
type = TypeInfo.getTypeInfo(Value.VARBINARY, 16, 0, null);
break;
default:
type = TypeInfo.getTypeInfo(info.returnDataType);
}
if (allConst) {
return ValueExpression.get(getValue(session));
}
return this;
}
@Override
public Value getValue(SessionLocal session) {
Value[] values = getArgumentsValues(session, args);
if (values == null) {
return ValueNull.INSTANCE;
}
Value v0 = getNullOrValue(session, args, values, 0);
Value v1 = getNullOrValue(session, args, values, 1);
Value result;
switch (info.type) {
case ADD_MONTHS:
result = DateTimeFunction.dateadd(session, DateTimeFunction.MONTH, v1.getInt(), v0);
break;
case SYS_GUID:
result = ValueUuid.getNewRandom().convertTo(TypeInfo.TYPE_VARBINARY);
break;
case TO_DATE:
result = ToDateParser.toDate(session, v0.getString(), v1 == null ? null : v1.getString());
break;
case TO_TIMESTAMP:
result = ToDateParser.toTimestamp(session, v0.getString(), v1 == null ? null : v1.getString());
break;
case TO_TIMESTAMP_TZ:
result = ToDateParser.toTimestampTz(session, v0.getString(), v1 == null ? null : v1.getString());
break;
default:
throw DbException.getInternalError("type=" + info.type);
}
return result;
}
}