Database not on the correct thread ... about grdb.swift HOT 10 CLOSED

Would you please reformat your code as below:

```swift
// yeah, Swift
do {
    // correctly indented
}
```

It will help a lot reading your question :-)

// yeah, Swift
do {
    // correctly indented
}

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yes, having a great difficult with code formatting ... seems to want to strip out tabs and cr/lf

from grdb.swift.

ok, that should do ..

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Thanks ;-)

OK now it's crystal clear. The inDatabase method executes its closure argument in a protected dispatch queue. And a database complains if it is used outside of this queue:

dbQueue.inDatabase { db in
    // In the queue of `db`
    try! dbQueueMerge.inDatabase {dbMerge in
        // In the queue of `dbMerge`
        // And there `db` complains it is not in its queue:
        try db.execute(...)
    }
}

OK. That's a pattern that is not supported today. I have to think about it.

Meanwhile, you have two possible workarounds:

1- First fetch all data in the source database queue, and then write in the destination database queue. It's much less memory efficient than your tight and sharp loop, I agree. But if you don't have too much data to copy, this solution can be an acceptable workaround.

2- If you actually copy the whole content of a database in another, use the backup method.

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Hmm, I was afraid you would tell me something like that. I would have thought that merging a second database is a (fairly) common need. In the merge process PK values change so I'll have to go with option one.

Hope you can figure something out ... and thanks for the speedy replies!

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I would have thought that merging a second database is a (fairly) common need.

There are my needs, the ones of my coworkers, and the ones of users like you who are kind enough to ask for a feature. Now the merge is on the list of feature requests :-)

Hope you can figure something out

So do I. Until this time, use a workaround, and stay tuned on GRDB :-)

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@mtissington OK I eventually managed to find a solution:

dbQueue1.inDatabase { db1 in 
    dbQueue2.inDatabase { db2 in 
        // Both db1 and db2 can be used here.
    }
}

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cool, will give it a try ....

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The fix has shipped in v0.66.0.

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confirmed that this now works - thanks

            try dbQueue.inTransaction { db in
                try dbQueueMerge.inDatabase {dbMerge in

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