Golang: Mysql Prepare Insert statements do not add rows into db table - mysql

Question

So I'm trying to use a mysql driver to insert data into a database.
Specifically, I'm using this one:
"github.com/go-sql-driver/mysql"
This is my code
func main() {
db, err := sql.Open("mysql", "psanker:123#/education_data")
err = db.Ping()
if err != nil {
fmt.Println("Failed to prepare connection to database")
log.Fatal("Error:", err.Error())
}
defer db.Close()
content, err := ioutil.ReadFile("activities.csv")
lines := strings.Split(string(content), "\r")
//only work so long as I have one district
rows, err := db.Query("SELECT id FROM districts")
var districtId int
defer rows.Close()
for rows.Next() {
err := rows.Scan(&districtId)
check(err)
}
for i, line := range lines {
if i > 1 {
splitStr := strings.Split(line, ",")
var activityCode string
if strings.Contains(splitStr[0], "-") {
//this is an activity
activityCode = splitStr[0]
stmt1, _ := db.Prepare("INSERT INTO activities(code) VALUES(?)")
stmt2, _ := db.Prepare("INSERT INTO activities(name) VALUES(?)")
res, _ := stmt1.Exec(splitStr[0])
stmt2.Exec(splitStr[1])
} else {
//this is a sub activity
stmt1, _ := db.Prepare("INSERT INTO sub_activities(code) VALUES(?)")
stmt2, _ := db.Prepare("INSERT INTO sub_activities(name) VALUES(?)")
stmt1.Exec(splitStr[0])
stmt2.Exec(splitStr[1])
if activityCode != "" {
rows, _ := db.Query("SELECT id from activities where code = ?", activityCode)
var activityId int
for rows.Next() {
err := rows.Scan(&activityId)
check(err)
stmt3, err := db.Prepare("INSERT INTO sub_activities(activity_id) VALUES(?)")
stmt3.Exec(activityId)
}
}
rows, _ := db.Query("SELECT id from sub_activities where code= ?", splitStr[0])
var sub_activityId int
for rows.Next() {
err := rows.Scan(&sub_activityId)
check(err)
stmt5, _ := db.Prepare("INSERT INTO sub_activity_expenditure(district_id) VALUES(?)")
stmt6, _ := db.Prepare("INSERT INTO sub_activity_expenditure(sub_activity_id) VALUES(?)")
stmt7, _ := db.Prepare("INSERT INTO sub_activity_expenditure(expenditure) VALUES(?)")
stmt5.Exec(districtId)
stmt6.Exec(sub_activityId)
stmt7.Exec(splitStr[2])
}
}
}
}
}
When I check Mysql database, there are no rows inserted into the tables. I think I'm accessing the right database because the initial query that gets id from districts is returning 1, which is correct.
What's going on?
EDIT
I have confirmed I'm in the right db by doing this
rows, err = db.Query("SELECT DATABASE();")
var test string
for rows.Next() {
rows.Scan(&test)
fmt.Println(test)
}
Which prints out education_data

Answer 1

As you are trying to insert into a table, I was reminded (in chat at least) that your columns are non-null and you really meant to create one row when you were in fact creating two. It failed on stmt1 and stmt2 because non-nullable columns were not given parameters to replace for all necessary data for insertion to succeed.
Focus on creating one row for stmt1 and stmt2 (combine them into a single stmt1 to execute with 2 parameters).
Make sure strings are wrapped with a single quote.