/** @pre SqlTypeUtil.sameNamedType(argTypes[0], (argTypes[1])) */
public RelDataType inferReturnType(SqlOperatorBinding opBinding) {
final RelDataType argType0 = opBinding.getOperandType(0);
final RelDataType argType1 = opBinding.getOperandType(1);
if (!(SqlTypeUtil.inCharOrBinaryFamilies(argType0)
&& SqlTypeUtil.inCharOrBinaryFamilies(argType1))) {
Util.pre(
SqlTypeUtil.sameNamedType(argType0, argType1),
"SqlTypeUtil.sameNamedType(argTypes[0], argTypes[1])");
}
SqlCollation pickedCollation = null;
if (SqlTypeUtil.inCharFamily(argType0)) {
if (!SqlTypeUtil.isCharTypeComparable(opBinding.collectOperandTypes().subList(0, 2))) {
throw opBinding.newError(
RESOURCE.typeNotComparable(
argType0.getFullTypeString(), argType1.getFullTypeString()));
}
pickedCollation =
SqlCollation.getCoercibilityDyadicOperator(
argType0.getCollation(), argType1.getCollation());
assert null != pickedCollation;
}
// Determine whether result is variable-length
SqlTypeName typeName = argType0.getSqlTypeName();
if (SqlTypeUtil.isBoundedVariableWidth(argType1)) {
typeName = argType1.getSqlTypeName();
}
RelDataType ret;
ret =
opBinding
.getTypeFactory()
.createSqlType(typeName, argType0.getPrecision() + argType1.getPrecision());
if (null != pickedCollation) {
RelDataType pickedType;
if (argType0.getCollation().equals(pickedCollation)) {
pickedType = argType0;
} else if (argType1.getCollation().equals(pickedCollation)) {
pickedType = argType1;
} else {
throw Util.newInternal("should never come here");
}
ret =
opBinding
.getTypeFactory()
.createTypeWithCharsetAndCollation(
ret, pickedType.getCharset(), pickedType.getCollation());
}
return ret;
}
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));
}
