CODEWITHSUNDEEP
databasesqlitegogo-sqlite3
guts_thakur
guts_thakur

Reputation: 21

Utilizing Sqlite `no such table` error in Go?

When working with the sqlite database in Go. During the testing I got the error: no such table: table_name. Well I know where the error is coming from.

But I want to know if there is a way that I can use this error message in Go, to do some work with it(like create that table in my code). I was trying to do something like this:

_, err := getState(dbconn) // This the function that retrieves the table that does not exists
if err != nil {
    if err == err.New("no such table: table_name") {
        // do the work
    }
}

Upvotes: 0

Views: 64

Answers (2)

riyaz-ali
riyaz-ali

Reputation: 9034

As mentioned elsewhere, you cannot compare the value returned by errors.New() to err using == operator as it'd compare for equality in reference and not the actual error type.

Instead, you can try either of the following approaches.

// compare the err's string value for exact match
if err != nil {
  if strings.EqualFold(err.Error(), "no such table: table_name") {
     // handle not found error
  }
}

type NotFound struct{}

func (nf *NotFound) Error() string { 
  return errors.New("no such table") 
}

func (nf *NotFound) Is(err error) bool {
  return err != nil && strings.HasPrefix(err.Error(), "no such table")
}

var ErrNotFound = &NotFound{}

// ...somewhere in your code
_, err := getState(dbConn)
if err != nil {
  // compare using errors.Is()
  if errors.Is(err, ErrNotFound) {
    // handle not found error
  } 
}

Upvotes: 0

Error
Error

Reputation: 180

In Go, errors returned by SQLite, such as "no such table," cannot be compared to a string using err.New("no such table: table_name"). This is because the "no such table" error is returned as an sqlite3.Error object, not as a string.

To handle this error, you should check the error message using the Error() method:

_, err = getState(dbconn)
if err != nil {
    if err.Error() == "no such table: table_name" {
        fmt.Println("Creating the table")
        // do the work
    }
}

Upvotes: -2

Related Questions