如何一次插入多个数据

Question

I know that Insert multiple data at once more efficiency:

INSERT INTO test(n1, n2, n3) 
VALUES(v1, v2, v3),(v4, v5, v6),(v7, v8, v9);

How to do that in golang?

data := []map[string]string{
   {"v1":"1", "v2":"1", "v3":"1"},
   {"v1":"2", "v2":"2", "v3":"2"},
   {"v1":"3", "v2":"3", "v3":"3"},
}
//I do not want to do it
for _, v := range data {
    sqlStr := "INSERT INTO test(n1, n2, n3) VALUES(?, ?, ?)"
    stmt, _ := db.Prepare(sqlStr)
    res, _ := stmt.Exec(v["v1"], v["v2"], v["v3"])
}

Use string splice, but it's not good. db.Prepare more safer, right?

sqlStr := "INSERT INTO test(n1, n2, n3) VALUES"
for k, v := range data {
    if k == 0 {
        sqlStr += fmt.Sprintf("(%v, %v, %v)", v["v1"], v["v2"], v["v3"])
    } else {
        sqlStr += fmt.Sprintf(",(%v, %v, %v)", v["v1"], v["v2"], v["v3"])
    } 
}
res, _ := db.Exec(sqlStr)

I need a function safer and efficient insert mulitple data at once.

Answer 1

why not something like this? (writing here without testing so there might be syntax errors):

sqlStr := "INSERT INTO test(n1, n2, n3) VALUES "
vals := []interface{}{}

for _, row := range data {
    sqlStr += "(?, ?, ?),"
    vals = append(vals, row["v1"], row["v2"], row["v3"])
}
//trim the last ,
sqlStr = sqlStr[0:len(sqlStr)-2]
//prepare the statement
stmt, _ := db.Prepare(sqlStr)

//format all vals at once
res, _ := stmt.Exec(vals...)