This can be used like in the test; I wrote a little wrapper around
sql.DB which uses this, and allows concurrent reads but just one single
write. This is perhaps a better generic "table locked"-solution than
setting the connections to 1 and/or cache=shared (although even better
would be to design your app in such a way that this doesn't happpen in
the first place, but even then a little seat belt isn't a bad thing).
The parsing adds about 0.1ms to 0.2ms of overhead in the wrapper, which
isn't too bad (and it caches the results, so only needs to do this
once).
At any rate, I can't really access functions from sqlite3-binding.c from
my application, so expose it via SQLiteStmt.
Commit 4f7abea96e added a test that uses Conn.Raw, which was added in
Go >= 1.13. The go-sqlite3 project runs tests with Go >= 1.11. Remove
the test from sqlite3_test.go, so it only runs with the correct
versions of Go.
Instead of adding a new test, modify the existing test that already
uses Conn.Raw() to check the type of driverConn.
* Fix "cannot start a transaction within a transaction" issue
[why]
If db.BeginTx(ctx, nil) context is cancelled too fast, "BEGIN" statement can be
completed inside DB, but we still try to cancel it with sqlite3_interrupt.
In such case we get context.Cancelled or context.DeadlineExceeded from exec(),
but operation really completed. Connection returned into pool, and returns "cannot
start a transaction within a transaction" error for next db.BeginTx() call.
[how]
Handle status code returned from cancelled operation.
[testing]
Added unit-test which reproduces issue.
* Reduce TestQueryRowContextCancelParallel concurrency
[why]
Tests times out in travis-ci when run with -race option.
Yasuhiro Matsumoto