return aggFnCount
	case e.Cast != nil:
		return sqlFnCast
	case e.Substring != nil:
		return sqlFnSubstring
	case e.Extract != nil:
		return sqlFnExtract
	case e.Trim != nil:
		return sqlFnTrim
	case e.DateAdd != nil:
		return sqlFnDateAdd
	case e.DateDiff != nil:
		return sqlFnDateDiff
	default:
		return ""
	}
}

// evalSQLFnNode assumes that the FuncExpr is not an aggregation
// function.

	TrimChars *PrimaryTerm `parser:"             @@?  "`
	TrimFrom  *PrimaryTerm `parser:"             \"FROM\" )? @@ \")\" "`
}

// DateAddFunc represents the DATE_ADD function
type DateAddFunc struct {
	DatePart  string       `parser:" \"DATE_ADD\" \"(\" @( \"YEAR\":Timeword | \"MONTH\":Timeword | \"DAY\":Timeword | \"HOUR\":Timeword | \"MINUTE\":Timeword | \"SECOND\":Timeword ) \",\""`
	Quantity  *Operand     `parser:" @@ \",\""`

     * commit was made.
     * <p>
     * This approach doesn't work with merge commits as these can introduce commits in the chronological order
     * after the fact e.x. a merge done today can add commits dated with yesterday so the result will no longer be
     * deterministic.
     * <p>
     * We don't use merge commits, but for additional safety we check that no such commits exist in the time period
     * we are interested in.