Panic in Batch.Column

[EpicStep]

Describe the bug

Panic in Batch.Column in case of invalid column index in b.batch.IsSend()

Code example

func test(conn driver.Conn) {
	b, err := conn.PrepareBatch(context.Background(), "INSERT INTO my_database.test")
	if err != nil {
		panic(err)
	}

	column := b.Column(1000) // invalid column index

	column.Append(nil) // nil dereference
}

Please, assign it to me

[jkaflik]

Assigned to you @EpicStep . Are you working on a fix?

[EpicStep]

@jkaflik yes, thanks