Is there a better way to marshal sql rows? - mysql

Question

I have the following struct:
type MyTable struct{
DBColA []byte `db:"cola" json:"-"`
ColA string `json:"cola"`
DBColB []byte `db:"colb" json:"-"`
ColB string `json:"colb"`
}
I map to []byte [to better handle null values in my sql][1]
When I grab the rows I need to output it as json. In order to do that I convert []byte to string:
var rows []*MyTable
if _, err := Session.Select(&rows, sql, args...); err != nil {
log.Println(err)
}
for _, row := range rows{
row.ColA = string(row.DBColA)
row.ColB = string(row.DBColB)
}
w.Header().Set("Content-Type", "application/json")
if err := json.NewEncoder(w).Encode(rows); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
It seems very inefficient to have DBColA and ColA in my struct and then converting DBColA to a string....I have a lot of columns. Is there a better way?
[1]: https://github.com/go-sql-driver/mysql/wiki/Examples

Answer 1

Have you tried gosqljson in https://github.com/elgs/gosqljson ?
See example:
```golang
package main
import (
"database/sql"
"fmt"
"github.com/elgs/gosqljson"
_ "github.com/go-sql-driver/mysql"
)
func main() {
ds := "username:password#tcp(host:3306)/db"
db, err := sql.Open("mysql", ds)
defer db.Close()
if err != nil {
fmt.Println("sql.Open:", err)
}
theCase := "lower" // "lower" default, "upper", camel
a, _ := gosqljson.QueryDbToArrayJson(db, theCase, "SELECT ID,NAME FROM t LIMIT ?,?", 0, 3)
fmt.Println(a)
// [["id","name"],["0","Alicia"],["1","Brian"],["2","Chloe"]]
m, _ := gosqljson.QueryDbToMapJson(db, theCase, "SELECT ID,NAME FROM t LIMIT ?,?", 0, 3)
fmt.Println(m)
// [{"id":"0","name":"Alicia"},{"id":"1","name":"Brian"},{"id":"2","name":"Chloe"}]
}
````