How to insert multiple rows - mysql

Question

I am actually very new to Go so wanted to know the best way to insert data like this
{
"moduleId":"M101",
"topicId":["tt","ee"]
}
in MySQL database using Go
type TopicModule struct {
ModuleId string `json:"moduleId" bson:"moduleId" form:"moduleId"`
TopicId []string `json:"topicId" bson:"topicId" form:"topicId"`
AddedBy string `json:"addedBy" bson:"addedBy" form:"addedBy"`
}
func AddTopicModuleHandler(ctx iris.Context) {
topicmodule := new(TopicModule)
if err := ctx.ReadJSON(topicmodule); err != nil {
panic(err)
ctx.StatusCode(400)
return
}
log.Println(topicmodule.TopicId)
code, created := AddTopicModule(*topicmodule)
if created {
ctx.JSON(topicmodule)
ctx.Redirect("/api/module/"+code, iris.StatusCreated)
}
}
func AddTopicModule(atm TopicModule) (string, bool) {
log.Println("the topic is ", atm.TopicId)
db := DatabaseAccess()
tx, _ := db.Begin()
stmt, err := tx.Prepare("insert into ModuleTopic(module_id, topic_id, added_by) Values(?,?,?) ")
res, err := stmt.Exec(atm.ModuleId, "Ricky")
res1, err := stmt.Exec(atm.ModuleId, "Ric")
if err != nil {
tx.Rollback()
}
tx.Commit()
log.Println(res, res1)
return "aa", true
}
The expected result is to add the array of JSON into MySQL.

Answer 1

You can not simply insert an array into the database. Instead, you should loop around the TopicId and insert them one by one
func AddTopicModule(atm TopicModule) (string, bool) {
log.Println("the topic is ", atm.TopicId)
db := DatabaseAccess()
tx, _ := db.Begin()
for _, value = range(atm.TopicId){
stmt, err := tx.Prepare("insert into ModuleTopic(module_id, topic_id, added_by) Values(?,?,?) ")
if err != nil {
return "", false
}
res, err := stmt.Exec(atm.ModuleId, value, "Harsh")
if err != nil {
tx.Rollback()
return "", false
}
tx.Commit()
}
return "aa", true
}
This will create 2 entries in the database for the JSON provided by you.
|---------------------|------------------|------------------|
| module_id | topic_id | added_by |
|---------------------|------------------|------------------|
| M101 | tt | Harsh |
|---------------------|------------------|------------------|
| M101 | ee | Harsh |
|---------------------|------------------|------------------|
To get them, simply query your database:
SELECT * FROM ModuleTopic WHERE module_id = M101;