How to import data from csv file into postegrsql using go? - postgresql

Question

I have a docker container with *.csv files in it. I want to import data from that files into my postgresql database. The tables creates from schema.sql file.
I need to import from 3 different csv files data into 3 different tables in my db.
I tried to make it with db.Exec('COPY <table_name> FROM <path> DELIMITER ',' CSV HEADER; but it didn't work (error: cannot open file, or file doesn't exist)
So i make the following function and it works fine, but i think it is not a good solution.
func AddSomeDataIntoTable(tableName, path string, fieldsQty int) error {
file, err := os.Open(path)
if err != nil {
return err
}
defer file.Close()
reader := csv.NewReader(file)
if _, err := reader.Read(); err == io.EOF {
return fmt.Errorf("error: empty file")
}
//loop of reading
for i := 0; ; i++ {
record, err := reader.Read()
if err != nil {
if err != io.EOF {
return fmt.Errorf("Error reading file: %w", err)
}
if i == 0 {
return fmt.Errorf("Malformed csv file: there's only headers and no values")
} else {
log.Print("end of file")
//end of the file
return nil
}
}
//malformed csv handling
if len(record) != fieldsQty {
return fmt.Errorf("Malformed csv file: wrong number of fields")
}
for _, v := range record {
if v == "" {
return fmt.Errorf("malformed csv file: empty fields")
}
}
_, err = uuid.Parse(record[0])
if err != nil {
return fmt.Errorf("malformed id, should be a uuid: %w", err)
}
switch tableName {
case "<table_name1>":
_, err = db.Pdb.Exec(`INSERT INTO <table_name1> (field1, field2, field3, field4, field5) VALUES ($1, $2, $3, $4, $5)`,
record[0], record[1], record[2], record[3], record[4])
if err != nil {
return fmt.Errorf("internal db problems: %w", err)
}
case "<table_name2":
_, err = db.Pdb.Exec(`INSERT INTO table_name2 (field1, field2) VALUES ($1, $2)`,
record[0], record[1])
if err != nil {
return fmt.Errorf("internal db problems: %w", err)
}
case "<table_name3>":
_, err = db.Pdb.Exec(`INSERT INTO table_name3 (field1, field2) VALUES ($1, $2)`,
record[0], record[1])
if err != nil {
return fmt.Errorf("internal db problems: %w", err)
}
default:
return fmt.Errorf("cannot find such table")
}
}
return nil
}
May be someone can advise me any other better solution?