charset option does not work. #1680
Description
Since v1.9.0, when initializing sql.DB with the charset option set in config.Params as shown in the following code, an error occurs during query execution:
config := mysql.NewConfig()
config.Net = "tcp"
config.Addr = "127.0.0.1:3306"
// etc...
config.Params = map[string]string{
"charset": "utf8mb4",
}
conn, err := mysql.NewConnector(config)
if err != nil {
log.Fatal(err)
}
db := sql.OpenDB(conn)
if _, err := db.Exec("SELECT 1"); err != nil {
log.Fatal(err)
}
// return Error 1193 (HY000): Unknown system variable 'charset'However, it works without any issues when initialized using config.FormatDSN():
config := mysql.NewConfig()
config.Net = "tcp"
config.Addr = "127.0.0.1:3306"
// etc...
config.Params = map[string]string{
"charset": "utf8mb4",
}
db, err := sql.Open("mysql", config.FormatDSN())
if err != nil {
log.Fatal(err)
}
if _, err := db.Exec("SELECT 1"); err != nil {
log.Fatal(err)
}I believe this is due to the change in the timing of interpreting the charset option in #1604 .
In the current implementation, it is interpreted within the ParseDSN method and stored in the config.charsets field.
Lines 525 to 527 in 58941dd
However, in the way I wrote, the connection is created without going through the ParseDSN method, so charset is sent as an invalid option.
The charset option should be interpreted regardless of the connection establishment procedure.