rowsscanner.go

package sqldb

// RowsScanner scans the values from multiple rows.
type RowsScanner interface {
	// ScanSlice scans one value per row into one slice element of dest.
	// dest must be a pointer to a slice with a row value compatible element type.
	// In case of zero rows, dest will be set to nil and no error will be returned.
	// In case of an error, dest will not be modified.
	// It is an error to query more than one column.
	ScanSlice(dest any) error

	// ScanStructSlice scans every row into the struct fields of dest slice elements.
	// dest must be a pointer to a slice of structs or struct pointers.
	// In case of zero rows, dest will be set to nil and no error will be returned.
	// In case of an error, dest will not be modified.
	// Every mapped struct field must have a corresponding column in the query results.
	ScanStructSlice(dest any) error

	// ScanAllRowsAsStrings scans the values of all rows as strings.
	// Byte slices will be interpreted as strings,
	// nil (SQL NULL) will be converted to an empty string,
	// all other types are converted with fmt.Sprint.
	// If true is passed for headerRow, then a row
	// with the column names will be prepended.
	ScanAllRowsAsStrings(headerRow bool) (rows [][]string, err error)

	// Columns returns the column names.
	Columns() ([]string, error)

	// ForEachRow will call the passed callback with a RowScanner for every row.
	// In case of zero rows, no error will be returned.
	ForEachRow(callback func(RowScanner) error) error

	// ForEachRowCall will call the passed callback with scanned values or a struct for every row.
	// If the callback function has a single struct or struct pointer argument,
	// then RowScanner.ScanStruct will be used per row,
	// else RowScanner.Scan will be used for all arguments of the callback.
	// If the function has a context.Context as first argument,
	// then the context of the query call will be passed on.
	// The callback can have no result or a single error result value.
	// If a non nil error is returned from the callback, then this error
	// is returned immediately by this function without scanning further rows.
	// In case of zero rows, no error will be returned.
	ForEachRowCall(callback any) error
}