case sqlFnDateDiff:
		return handleDateDiff(r, e.DateDiff, tableAlias)
	}

	// For all simple argument functions, we evaluate the arguments here
	argVals := make([]*Value, len(e.SFunc.ArgsList))
	for i, arg := range e.SFunc.ArgsList {
		argVals[i], err = arg.evalNode(r, tableAlias)
		if err != nil {
			return nil, err
		}
	}

	switch e.getFunctionName() {
	case sqlFnCoalesce:
		return coalesce(argVals)

	FunctionName string `parser:" @(\"AVG\" | \"MAX\" | \"MIN\" | \"SUM\" |  \"COALESCE\" | \"NULLIF\" | \"TO_STRING\" | \"TO_TIMESTAMP\" | \"UTCNOW\" | \"CHAR_LENGTH\" | \"CHARACTER_LENGTH\" | \"LOWER\" | \"UPPER\") "`

	ArgsList []*Expression `parser:"\"(\" (@@ (\",\" @@)*)?\")\""`
}

// CountFunc represents the COUNT sql function
type CountFunc struct {
	StarArg bool        `parser:" \"COUNT\" \"(\" ( @\"*\"?"`