/**
* Returns true if a type is a simple cast of another type. It is if the cast type is nullable and
* the cast is one of the following:
* <li>x TO x
* <li>char(n) TO varchar(m)
* <li>varchar(n) TO varchar(m)
* <li>x not null TO x nullable
*
* @param origType original type passed into the cast operand
* @param castType type the operand will be casted to
* @return true if the cast is simple
*/
private boolean isCastSimple(RelDataType origType, RelDataType castType) {
SqlTypeName origTypeName = origType.getSqlTypeName();
SqlTypeName castTypeName = castType.getSqlTypeName();
if (!(castType.isNullable())) {
return false;
}
Charset origCharset = origType.getCharset();
Charset castCharset = castType.getCharset();
if ((origCharset != null) || (castCharset != null)) {
if ((origCharset == null) || (castCharset == null)) {
return false;
}
if (!origCharset.equals(castCharset)) {
return false;
}
}
return ((origType == castType)
|| ((origTypeName == SqlTypeName.CHAR) && (castTypeName == SqlTypeName.VARCHAR))
|| ((origTypeName == SqlTypeName.VARCHAR) && (castTypeName == SqlTypeName.VARCHAR))
|| ((origTypeName == castTypeName)
&& (origType.getPrecision() == castType.getPrecision())
&& ((origTypeName != SqlTypeName.DECIMAL)
|| (origType.getScale() == castType.getScale()))
&& (!origType.isNullable() && castType.isNullable())));
}
/**
* Gets the right hand expression as a valid value to be assigned to the left hand side. Usually
* returns the original rhs. However, if the lhs is of a primitive type, and the rhs is an
* explicit null, returns a primitive value instead.
*/
private Expression rhsAsValue() {
if (SqlTypeUtil.isJavaPrimitive(lhsType) && (rhsType.getSqlTypeName() == SqlTypeName.NULL)) {
if (lhsType.getSqlTypeName() == SqlTypeName.BOOLEAN) {
return Literal.constantFalse();
} else {
return Literal.constantZero();
}
}
return rhsExp;
}
public int getFieldJdbcType(int fieldOrdinal) {
RelDataType type = getFieldNamedType(fieldOrdinal);
SqlTypeName typeName = type.getSqlTypeName();
if (typeName == null) {
return Types.OTHER;
}
return typeName.getJdbcOrdinal();
}
/**
* Checks for overflow when assigning one primitive type to another. Non-primitive types check
* for overflow during assignment.
*/
private void checkOverflow() {
String maxLiteral = null;
String minLiteral = null;
if (lhsType == null) {
return;
}
// Assume that equivalent types can be assigned without overflow
if (lhsType.getSqlTypeName() == rhsType.getSqlTypeName()) {
return;
}
// Approximate numerics have a wider range than exact numerics
if (SqlTypeUtil.isApproximateNumeric(lhsType) && SqlTypeUtil.isExactNumeric(rhsType)) {
return;
}
// We can skip an error check if the left type is "larger"
if (SqlTypeUtil.isIntType(lhsType)
&& SqlTypeUtil.isIntType(rhsType)
&& (SqlTypeUtil.maxValue(lhsType) >= SqlTypeUtil.maxValue(rhsType))) {
return;
}
if (SqlTypeUtil.isExactNumeric(lhsType)) {
String numClassName = SqlTypeUtil.getNumericJavaClassName(lhsType);
minLiteral = numClassName + ".MIN_VALUE";
maxLiteral = numClassName + ".MAX_VALUE";
} else if (SqlTypeUtil.isApproximateNumeric(lhsType)) {
String numClassName = SqlTypeUtil.getNumericJavaClassName(lhsType);
maxLiteral = numClassName + ".MAX_VALUE";
minLiteral = "-" + maxLiteral;
}
if (maxLiteral == null) {
return;
}
Statement ifstmt =
new IfStatement(
new BinaryExpression(
new BinaryExpression(
rhsExp, BinaryExpression.LESS, new Literal(Literal.STRING, minLiteral)),
BinaryExpression.LOGICAL_OR,
new BinaryExpression(
rhsExp, BinaryExpression.GREATER, new Literal(Literal.STRING, maxLiteral))),
getThrowStmtList());
addStatement(ifstmt);
}
public RelDataType getFieldType(int fieldOrdinal) {
RelDataType namedType = getFieldNamedType(fieldOrdinal);
if (namedType.getSqlTypeName() == SqlTypeName.DISTINCT) {
// for most metadata calls, report information about the
// predefined type on which the distinct type is based
return namedType.getFields()[0].getType();
} else {
return namedType;
}
}
public int getFieldScale(int fieldOrdinal) {
RelDataType type = getFieldType(fieldOrdinal);
SqlTypeName typeName = type.getSqlTypeName();
if (typeName == null) {
return 0;
}
if (typeName.allowsPrecScale(true, true)) {
return type.getScale();
} else {
return 0;
}
}
private boolean requiresSpecializedCast() {
if ((rhsType != null)
&& (SqlTypeUtil.isNumeric(rhsType) || (rhsType.getSqlTypeName() == SqlTypeName.BOOLEAN))
&& SqlTypeUtil.inCharOrBinaryFamilies(lhsType)
&& !SqlTypeUtil.isLob(lhsType)) {
// Boolean or Numeric to String.
// sometimes the Integer got slipped by.
return true;
} else {
return false;
}
}
public String getFieldTypeName(int fieldOrdinal) {
RelDataType type = getFieldNamedType(fieldOrdinal);
SqlTypeName typeName = type.getSqlTypeName();
if (typeName == null) {
return type.toString();
}
switch (typeName) {
case STRUCTURED:
case DISTINCT:
return type.getSqlIdentifier().toString();
case INTERVAL_DAY_TIME:
case INTERVAL_YEAR_MONTH:
return type.toString();
}
return typeName.name();
}
/**
* Implement the cast expression.
*
* <p>TODO: check for overflow
*
* @return the rhs expression casted as the lhs type
*/
public Expression implement() {
// Check for invalid null assignment. Code generated afterwards
// can assume null will never be assigned to a not null value.
checkNotNull();
// Check for an explicit rhs null value. Code generated
// afterwards need never check for an explicit null.
if (rhsType.getSqlTypeName() == SqlTypeName.NULL) {
if (lhsType.isNullable()) {
return castFromNull();
} else {
// NOTE jvs 27-Jan-2005: this code will never actually
// be executed do to previous checkNotNull test, but
// it still has to compile!
return rhsAsValue();
}
}
// Case when left hand side is a nullable primitive
if (translator.isNullablePrimitive(lhsType)) {
if (SqlTypeUtil.isJavaPrimitive(rhsType)
&& (!rhsType.isNullable() || translator.isNullablePrimitive(rhsType))) {
return castPrimitiveToNullablePrimitive();
}
return castToAssignableValue();
}
// Case when left hand side is a not nullable primitive
if (SqlTypeUtil.isJavaPrimitive(lhsType)) {
return castToNotNullPrimitive();
}
// Case when left hand side is a structure
if (lhsType.isStruct()) {
assert (rhsType.isStruct());
// TODO jvs 27-May-2004: relax this assert and deal with
// conversions, null checks, etc.
assert (lhsType.equals(rhsType));
return getDirectAssignment();
}
// Default is to treat non-primitives as AssignableValue
return castToAssignableValue();
}
private SqlOperator toOp(SqlIdentifier name, Function function) {
List<RelDataType> argTypes = new ArrayList<RelDataType>();
List<SqlTypeFamily> typeFamilies = new ArrayList<SqlTypeFamily>();
for (FunctionParameter o : function.getParameters()) {
final RelDataType type = o.getType(typeFactory);
argTypes.add(type);
typeFamilies.add(Util.first(type.getSqlTypeName().getFamily(), SqlTypeFamily.ANY));
}
final RelDataType returnType;
if (function instanceof ScalarFunction) {
return new SqlUserDefinedFunction(
name,
ReturnTypes.explicit(Schemas.proto((ScalarFunction) function)),
InferTypes.explicit(argTypes),
OperandTypes.family(typeFamilies),
toSql(argTypes),
function);
} else if (function instanceof AggregateFunction) {
returnType = ((AggregateFunction) function).getReturnType(typeFactory);
return new SqlUserDefinedAggFunction(
name,
ReturnTypes.explicit(returnType),
InferTypes.explicit(argTypes),
OperandTypes.family(typeFamilies),
(AggregateFunction) function);
} else if (function instanceof TableMacro) {
return new SqlUserDefinedTableMacro(
name,
ReturnTypes.CURSOR,
InferTypes.explicit(argTypes),
OperandTypes.family(typeFamilies),
(TableMacro) function);
} else if (function instanceof TableFunction) {
return new SqlUserDefinedTableFunction(
name,
ReturnTypes.CURSOR,
InferTypes.explicit(argTypes),
OperandTypes.family(typeFamilies),
toSql(argTypes),
(TableFunction) function);
} else {
throw new AssertionError("unknown function type " + function);
}
}
/**
* Determines whether a {@link RexCall} requires decimal expansion. It usually requires expansion
* if it has decimal operands.
*
* <p>Exceptions to this rule are:
*
* <ul>
* <li>isNull doesn't require expansion
* <li>It's okay to cast decimals to and from char types
* <li>It's okay to cast nulls as decimals
* <li>Casts require expansion if their return type is decimal
* <li>Reinterpret casts can handle a decimal operand
* </ul>
*
* @param expr expression possibly in need of expansion
* @param recurse whether to check nested calls
* @return whether the expression requires expansion
*/
public static boolean requiresDecimalExpansion(RexNode expr, boolean recurse) {
if (!(expr instanceof RexCall)) {
return false;
}
RexCall call = (RexCall) expr;
boolean localCheck = true;
switch (call.getKind()) {
case Reinterpret:
case IsNull:
localCheck = false;
break;
case Cast:
RelDataType lhsType = call.getType();
RelDataType rhsType = call.operands[0].getType();
if (rhsType.getSqlTypeName() == SqlTypeName.NULL) {
return false;
}
if (SqlTypeUtil.inCharFamily(lhsType) || SqlTypeUtil.inCharFamily(rhsType)) {
localCheck = false;
} else if (SqlTypeUtil.isDecimal(lhsType) && (lhsType != rhsType)) {
return true;
}
break;
default:
localCheck = call.getOperator().requiresDecimalExpansion();
}
if (localCheck) {
if (SqlTypeUtil.isDecimal(call.getType())) {
// NOTE jvs 27-Mar-2007: Depending on the type factory, the
// result of a division may be decimal, even though both inputs
// are integer.
return true;
}
for (int i = 0; i < call.operands.length; i++) {
if (SqlTypeUtil.isDecimal(call.operands[i].getType())) {
return true;
}
}
}
return (recurse && requiresDecimalExpansion(call.operands, recurse));
}
// implement FarragoOJRexImplementor
public Expression implementFarrago(
FarragoRexToOJTranslator translator, RexCall call, Expression[] operands) {
RelDataType lhsType = call.getType();
RelDataType rhsType = call.operands[0].getType();
Expression rhsExp = operands[0];
SqlTypeName lhsTypeName = lhsType.getSqlTypeName();
if ((lhsTypeName == SqlTypeName.CURSOR) || (lhsTypeName == SqlTypeName.COLUMN_LIST)) {
// Conversion should already have been taken care of outside.
return rhsExp;
}
// NOTE jvs 19-Nov-2008: In some cases (e.g. FRG-273) a cast
// may be illegal at the SQL level, but allowable as part of
// implementation, so don't try to enforce
// SqlTypeUtil.canCastFrom here. Anything which was supposed
// to have been prevented should already have been caught
// by the validator.
CastHelper helper =
new CastHelper(translator, null, call.toString(), lhsType, rhsType, null, rhsExp);
return helper.implement();
}
/**
* Casts the rhs to a non nullable primitive value. Non nullable primitive values only have a
* single value field.
*/
private Expression castToNotNullPrimitive() {
// If the left and the right types are the same, perform a
// trivial cast.
if (lhsType == rhsType) {
return getDirectAssignment();
}
// Retrieve the value of the right side if it is a nullable
// primitive or a Datetime or an Interval type.
// TODO: is Decimal a nullable primitive?
if (translator.isNullablePrimitive(rhsType)
|| SqlTypeUtil.isDatetime(rhsType)
|| SqlTypeUtil.isInterval(rhsType)) {
rhsExp = getValue(rhsType, rhsExp);
}
// Get the name of the numeric class such as Byte, Short, etc.
String numClassName = SqlTypeUtil.getNumericJavaClassName(lhsType);
OJClass lhsClass = getLhsClass();
// When casting from a string (or binary) to a number, trim the
// value and perform the cast by calling a class-specific parsing
// function.
if ((numClassName != null)
&& SqlTypeUtil.inCharOrBinaryFamilies(rhsType)
&& !SqlTypeUtil.isLob(rhsType)) {
// TODO: toString will cause too much garbage collection.
rhsExp = new MethodCall(rhsExp, "toString", new ExpressionList());
rhsExp = new MethodCall(rhsExp, "trim", new ExpressionList());
String methodName = "parse" + numClassName;
if (lhsType.getSqlTypeName() == SqlTypeName.INTEGER) {
methodName = "parseInt";
}
rhsExp =
new MethodCall(
new Literal(Literal.STRING, numClassName), methodName, new ExpressionList(rhsExp));
Variable outTemp = translator.getRelImplementor().newVariable();
translator.addStatement(
new VariableDeclaration(
TypeName.forOJClass(lhsClass), new VariableDeclarator(outTemp.toString(), rhsExp)));
rhsExp = outTemp;
// Note: this check for overflow should only be required
// when the string conversion does not perform a check.
checkOverflow();
} else if ((lhsType.getSqlTypeName() == SqlTypeName.BOOLEAN)
&& SqlTypeUtil.inCharOrBinaryFamilies(rhsType)
&& !SqlTypeUtil.isLob(rhsType)) {
// Casting from string to boolean relies on the runtime type.
// Note: string is trimmed by conversion method.
// TODO: toString will cause too much garbage collection.
Expression str = new MethodCall(rhsExp, "toString", new ExpressionList());
rhsExp =
new MethodCall(
OJClass.forClass(NullablePrimitive.NullableBoolean.class),
"convertString",
new ExpressionList(str));
} else {
// In general, check for overflow
checkOverflow();
}
roundAsNeeded();
rhsExp = new CastExpression(lhsClass, rhsExp);
return getDirectAssignment();
}
private Expression castToAssignableValueImpl() {
if (requiresSpecializedCast()) {
if (rhsType.isNullable() && (!SqlTypeUtil.isDecimal(rhsType))) {
rhsExp = getValue(rhsType, rhsExp);
}
addStatement(
new ExpressionStatement(
new MethodCall(
lhsExp,
"cast",
new ExpressionList(rhsExp, Literal.makeLiteral(lhsType.getPrecision())))));
} else {
// Set current_date for casting time to timestamp. If
// rhsType is null then we may have to be ready for anything.
// But it will be null even for current_timestamp, so the
// condition below seems a bit excessive.
if ((lhsType.getSqlTypeName() == SqlTypeName.TIMESTAMP)
&& ((rhsType == null) || (rhsType.getSqlTypeName() == SqlTypeName.TIME))) {
addStatement(
new ExpressionStatement(
new MethodCall(lhsExp, "setCurrentDate", new ExpressionList(getCurrentDate()))));
}
addStatement(
new ExpressionStatement(
new MethodCall(
lhsExp, AssignableValue.ASSIGNMENT_METHOD_NAME, new ExpressionList(rhsExp))));
}
// Trim precision of datetime values.
//
if (((lhsType.getSqlTypeName() == SqlTypeName.TIMESTAMP)
|| (lhsType.getSqlTypeName() == SqlTypeName.TIME))) {
if ((rhsType != null)
// FIXME: JavaType(java.sql.Time) and
// JavaType(java.sql.Timestamp) say they support precision
// but do not.
&& !rhsType.toString().startsWith("JavaType(")
&& rhsType.getSqlTypeName().allowsPrec()
&& (lhsType.getPrecision() < rhsType.getPrecision())) {
int lhsPrecision = lhsType.getPrecision();
if (lhsPrecision == -1) {
lhsPrecision = 0;
}
addStatement(
new ExpressionStatement(
new MethodCall(
lhsExp,
SqlDateTimeWithoutTZ.ADJUST_PRECISION_METHOD_NAME,
new ExpressionList(Literal.makeLiteral(lhsPrecision)))));
}
}
boolean mayNeedPadOrTruncate = false;
if (SqlTypeUtil.inCharOrBinaryFamilies(lhsType) && !SqlTypeUtil.isLob(lhsType)) {
mayNeedPadOrTruncate = true;
}
if (mayNeedPadOrTruncate) {
// check overflow if it is datetime.
// TODO: should check it at the run time.
// so, it should be in the
// cast(SqlDateTimeWithTZ, int precision);
if ((rhsType != null) && (rhsType.getSqlTypeName() != null)) {
SqlTypeName typeName = rhsType.getSqlTypeName();
int precision = 0;
switch (typeName) {
case DATE:
precision = 10;
break;
case TIME:
precision = 8;
break;
case TIMESTAMP:
precision = 19;
break;
}
if ((precision != 0) && (precision > lhsType.getPrecision())) {
addStatement(
new IfStatement(
new BinaryExpression(
Literal.makeLiteral(precision),
BinaryExpression.GREATER,
Literal.makeLiteral(lhsType.getPrecision())),
getThrowStmtList()));
}
}
if ((rhsType != null)
&& (rhsType.getFamily() == lhsType.getFamily())
&& !SqlTypeUtil.isLob(rhsType)) {
// we may be able to skip pad/truncate based on
// known facts about source and target precisions
if (SqlTypeUtil.isBoundedVariableWidth(lhsType)) {
if (lhsType.getPrecision() >= rhsType.getPrecision()) {
// target precision is greater than source
// precision, so truncation is impossible
// and we can skip adjustment
return lhsExp;
}
} else {
if ((lhsType.getPrecision() == rhsType.getPrecision())
&& !SqlTypeUtil.isBoundedVariableWidth(rhsType)) {
// source and target are both fixed-width, and
// precisions are the same, so there's no adjustment
// needed
return lhsExp;
}
}
}
// determine target precision
Expression precisionExp = Literal.makeLiteral(lhsType.getPrecision());
// need to pad only for fixed width
Expression needPadExp = Literal.makeLiteral(!SqlTypeUtil.isBoundedVariableWidth(lhsType));
// pad character is 0 for binary, space for character
Expression padByteExp;
if (!SqlTypeUtil.inCharFamily(lhsType)) {
padByteExp = new CastExpression(OJSystem.BYTE, Literal.makeLiteral(0));
} else {
padByteExp = new CastExpression(OJSystem.BYTE, Literal.makeLiteral(' '));
}
// generate the call to do the job
addStatement(
new ExpressionStatement(
new MethodCall(
lhsExp,
BytePointer.ENFORCE_PRECISION_METHOD_NAME,
new ExpressionList(precisionExp, needPadExp, padByteExp))));
}
return lhsExp;
}
