/*
* 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.TypedValueExpression;
import org.h2.expression.function.CoalesceFunction;
import org.h2.expression.function.CurrentDateTimeValueFunction;
import org.h2.expression.function.RandFunction;
import org.h2.expression.function.StringFunction;
import org.h2.message.DbException;
import org.h2.value.TypeInfo;
import org.h2.value.Value;
import org.h2.value.ValueBigint;
import org.h2.value.ValueNull;
/**
* Functions for {@link org.h2.engine.Mode.ModeEnum#MSSQLServer} compatibility
* mode.
*/
public final class FunctionsMSSQLServer extends ModeFunction {
private static final HashMap<String, FunctionInfo> FUNCTIONS = new HashMap<>();
private static final int CHARINDEX = 4001;
private static final int GETDATE = CHARINDEX + 1;
private static final int ISNULL = GETDATE + 1;
private static final int LEN = ISNULL + 1;
private static final int NEWID = LEN + 1;
private static final int NEWSEQUENTIALID = NEWID + 1;
private static final int SCOPE_IDENTITY = NEWSEQUENTIALID + 1;
private static final TypeInfo SCOPE_IDENTITY_TYPE = TypeInfo.getTypeInfo(Value.NUMERIC, 38, 0, null);
static {
FUNCTIONS.put("CHARINDEX", new FunctionInfo("CHARINDEX", CHARINDEX, VAR_ARGS, Value.INTEGER, true, true));
FUNCTIONS.put("GETDATE", new FunctionInfo("GETDATE", GETDATE, 0, Value.TIMESTAMP, false, true));
FUNCTIONS.put("LEN", new FunctionInfo("LEN", LEN, 1, Value.INTEGER, true, true));
FUNCTIONS.put("NEWID", new FunctionInfo("NEWID", NEWID, 0, Value.UUID, true, false));
FUNCTIONS.put("NEWSEQUENTIALID",
new FunctionInfo("NEWSEQUENTIALID", NEWSEQUENTIALID, 0, Value.UUID, true, false));
FUNCTIONS.put("ISNULL", new FunctionInfo("ISNULL", ISNULL, 2, Value.NULL, false, true));
FUNCTIONS.put("SCOPE_IDENTITY",
new FunctionInfo("SCOPE_IDENTITY", SCOPE_IDENTITY, 0, Value.NUMERIC, 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 FunctionsMSSQLServer getFunction(String upperName) {
FunctionInfo info = FUNCTIONS.get(upperName);
if (info != null) {
return new FunctionsMSSQLServer(info);
}
return null;
}
private FunctionsMSSQLServer(FunctionInfo info) {
super(info);
}
@Override
protected void checkParameterCount(int len) {
int min, max;
switch (info.type) {
case CHARINDEX:
min = 2;
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 Value getValue(SessionLocal session) {
Value[] values = getArgumentsValues(session, args);
if (values == null) {
return ValueNull.INSTANCE;
}
Value v0 = getNullOrValue(session, args, values, 0);
switch (info.type) {
case LEN: {
long len;
if (v0.getValueType() == Value.CHAR) {
String s = v0.getString();
int l = s.length();
while (l > 0 && s.charAt(l - 1) == ' ') {
l--;
}
len = l;
} else {
len = v0.charLength();
}
return ValueBigint.get(len);
}
case SCOPE_IDENTITY:
return session.getLastIdentity().convertTo(type);
default:
throw DbException.getInternalError("type=" + info.type);
}
}
@Override
public Expression optimize(SessionLocal session) {
switch (info.type) {
case CHARINDEX:
return new StringFunction(args, StringFunction.LOCATE).optimize(session);
case GETDATE:
return new CurrentDateTimeValueFunction(CurrentDateTimeValueFunction.LOCALTIMESTAMP, 3).optimize(session);
case ISNULL:
return new CoalesceFunction(CoalesceFunction.COALESCE, args).optimize(session);
case NEWID:
case NEWSEQUENTIALID:
return new RandFunction(null, RandFunction.RANDOM_UUID).optimize(session);
case SCOPE_IDENTITY:
type = SCOPE_IDENTITY_TYPE;
break;
default:
type = TypeInfo.getTypeInfo(info.returnDataType);
if (optimizeArguments(session)) {
return TypedValueExpression.getTypedIfNull(getValue(session), type);
}
}
return this;
}
}