SelectFmtSIMDJSON
	// SelectFmtParquet - Parquet format
	SelectFmtParquet
)

// WriteCSVOpts - encapsulates options for Select CSV output
type WriteCSVOpts struct {
	FieldDelimiter rune
	Quote          rune
	QuoteEscape    rune
	AlwaysQuote    bool
}

// Record - is a type containing columns and their values.
type Record interface {
	Get(name string) (*Value, error)

	// Set a value.

func FileWithLineNum() string {
	frame := CallerFrame()
	if frame.PC != 0 {
		return string(strconv.AppendInt(append([]byte(frame.File), ':'), int64(frame.Line), 10))
	}

	return ""
}

func IsInvalidDBNameChar(c rune) bool {
	return !unicode.IsLetter(c) && !unicode.IsNumber(c) && c != '.' && c != '*' && c != '_' && c != '$' && c != '@'
}

// CheckTruth check string true or not
func CheckTruth(vals ...string) bool {

	}

	// write surrogate pair
	d.scratch.addRune(utf16.DecodeRune(r, r2))
	c = d.next()
	goto scan
}

// u4 reads four bytes following a \u escape
func (d *Decoder) u4() rune {
	// logic taken from:
	// github.com/buger/jsonparser/blob/master/escape.go#L20
	var h [4]int
	for i := range 4 {
		c := d.next()
		switch {
		case c >= '0' && c <= '9':
			h[i] = int(c - '0')

			i++
		}

		// Trim whitespace of segment
		segmentStart, segmentEnd := start, i
		for segmentStart < segmentEnd && unicode.IsSpace(rune(path[segmentStart])) {
			segmentStart++
		}
		for segmentEnd > segmentStart && unicode.IsSpace(rune(path[segmentEnd-1])) {
			segmentEnd--
		}

		// Check for ".." or "."
		switch {

				if err != nil {
					return nil, err
				}
				buf = bytes.NewBuffer(b)
			}
			if c.Bool("export") {
				file := file
				if !c.Bool("combine") {
					file = strings.Map(func(r rune) rune {
						switch {
						case r >= 'a' && r <= 'z':
							return r
						case r >= 'A' && r <= 'Z':
							return r
						case r >= '0' && r <= '9':
							return r

			return nil, err2
		}

		inferTypeAsString(escapeVal)

		escapeStr, ok := escapeVal.ToString()
		if !ok {
			err := errLikeNonStrArg
			return nil, errLikeInvalidInputs(err)
		}

		if len([]rune(escapeStr)) > 1 {
			err := errLikeInvalidEscape
			return nil, errLikeInvalidInputs(err)
		}
	}

	matchResult, err := evalSQLLike(s, patternStr, escape)
	if err != nil {
		return nil, err
	}

	s, ok := v.ToString()
	if !ok {
		err := fmt.Errorf("%s/%s expects a string argument", sqlFnCharLength, sqlFnCharacterLength)
		return nil, errIncorrectSQLFunctionArgumentType(err)
	}
	return FromInt(int64(len([]rune(s)))), nil
}

func lowerCase(v *Value) (*Value, error) {
	inferTypeAsString(v)
	s, ok := v.ToString()
	if !ok {
		err := fmt.Errorf("%s expects a string argument", sqlFnLower)

			AllowQuotedRecordDelimiter: false,
			unmarshaled:                true,
		})

		for {
			record, err = r.Read(record)
			if err != nil {
				break
			}
			opts := sql.WriteCSVOpts{
				FieldDelimiter: []rune(c.fieldDelimiter)[0],
				Quote:          '"',
				QuoteEscape:    '"',
				AlwaysQuote:    false,
			}
			record.WriteCSV(&result, opts)
			result.Truncate(result.Len() - 1)
			result.WriteString(c.recordDelimiter)

		// add underscore if last letter is capital letter
		// add underscore when previous letter is lowercase
		// add underscore when next letter is lowercase
		if (i != 0 || i == l-1) && ((i > 0 && rune(camel[i-1]) >= 'a') ||
			(i < l-1 && rune(camel[i+1]) >= 'a')) {
			b.WriteRune('_')
		}
		b.WriteRune(v + 'a' - 'A')
	}
	return b.String()

**FastAPI** créera l'objet de type `BackgroundTasks` pour vous et le passera comme paramètre.

## Créer une fonction de tâche

Une fonction à exécuter comme tâche d'arrière-plan est juste une fonction standard qui peut recevoir des paramètres.

Elle peut être une fonction asynchrone (`async def`) ou une fonction normale (`def`), **FastAPI** saura la gérer correctement.