When I use scan I have to write all the variables into the scan beforehand. i need a solution where i can use data using things like sprintf

Is there a way I can access the data without defining a variable?

    func (dbs *item) ReadQuery() {
        var (
            unit_name, unit_position_name string
        )

        rows, err := db.Query(dbs.query)

        for rows.Next() {
            rows.Scan(&unit_name, &unit_position_name)

            if err != nil {
                log.Fatal(err)
            }

        }

    }

for example;

row["unit_name"]

or

unit_name,unit_position string

val:= fmt.Sprintf("%s , %s",unit_name,unit_position_name)
row[val]

CodePudding user response：

Here's how to scan a row without explicitly declaring a variable for value in the row.

Make a slice for the values. Make a slice with the address of those values. Scan to the addresses.

func example(db *sql.DB, query string) {
    rows, err := db.Query(query)
    if err != nil {
        log.Fatal(err)
    }
    cols, err := rows.Columns()
    if err != nil {
        log.Fatal(err)
    }
    addrs := make([]any, len(cols))
    for rows.Next() {
        values := make([]any, len(cols))
        for i := range addrs {
            addrs[i] = &values[i]
        }
        rows.Scan(addrs...)
        if err != nil {
            log.Fatal(err)
        }
        // The variable values contains the row values.
        // Here's an example of how to use the values.  
        // Replace the for loop with your code to
        // process the row.
        for i := range cols {
            fmt.Printf("%s: %v\n", cols[i], values[i])
        }
    }
}