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);
}
}
/** The <code>OVERLAY</code> function. */
public class SqlOverlayFunction extends SqlFunction {
// ~ Static fields/initializers ---------------------------------------------
private static final SqlOperandTypeChecker OTC_CUSTOM =
OperandTypes.or(
OperandTypes.STRING_STRING_INTEGER, OperandTypes.STRING_STRING_INTEGER_INTEGER);
// ~ Constructors -----------------------------------------------------------
public SqlOverlayFunction() {
super(
"OVERLAY",
SqlKind.OTHER_FUNCTION,
ReturnTypes.DYADIC_STRING_SUM_PRECISION_NULLABLE_VARYING,
null,
OTC_CUSTOM,
SqlFunctionCategory.STRING);
}
// ~ Methods ----------------------------------------------------------------
public void unparse(SqlWriter writer, SqlNode[] operands, int leftPrec, int rightPrec) {
final SqlWriter.Frame frame = writer.startFunCall(getName());
operands[0].unparse(writer, leftPrec, rightPrec);
writer.sep("PLACING");
operands[1].unparse(writer, leftPrec, rightPrec);
writer.sep("FROM");
operands[2].unparse(writer, leftPrec, rightPrec);
if (4 == operands.length) {
writer.sep("FOR");
operands[3].unparse(writer, leftPrec, rightPrec);
}
writer.endFunCall(frame);
}
public String getSignatureTemplate(final int operandsCount) {
switch (operandsCount) {
case 3:
return "{0}({1} PLACING {2} FROM {3})";
case 4:
return "{0}({1} PLACING {2} FROM {3} FOR {4})";
}
assert false;
return null;
}
}