How to dump in memory database?

[erkinsergey]

I have an in memory database:

const sqlite3 = require('sqlite3');
const db = new sqlite3.Database(':memory:');
... // create structure and fill data

Is it possible to get a database dump (without getting all data from all tables manually)?

[erkinsergey]

I try call undocumented method backup

db.backup('mydump.sql', () => 
{
   console.log('dump ready!');
});

mydump.sql is created but it is always empty... The database exactly have data.

[gms1]

thanks; I didn't know this is even supported; just found the corresponding PR
#1116
and will test this in the next days

[gms1]

looks good; essentially it works as described in this PR

about:

var backup = db.backup('backup.db');
backup.step(-1);
backup.finish();

of course backup.step is asynchronous, so please provide a callback (or poll until one of backup.complete or backup.failed or backup.idle is true)

about #1116 (comment)
@paulfitz
the mentioned commit did not find its way into the master branch. When I try to pass in a database object, I get the original error "Filename expected".

[gms1]

and the JSDoc for Database#backup seems to be partially wrong; sourceName and destName are probably swapped

https://github.com/paulfitz/node-sqlite3/blob/master/lib/sqlite3.js

// Database#backup(filename, destName, sourceName, filenameIsDest, [callback])
...
        backup = new Backup(this, arguments[0], arguments[1], arguments[2], arguments[3], arguments[4]);
};

https://github.com/mapbox/node-sqlite3/blob/master/src/backup.cc

        Napi::String filename = info[1].As<Napi::String>();
        Napi::String sourceName = info[2].As<Napi::String>();
        Napi::String destName = info[3].As<Napi::String>();
        Napi::Boolean filenameIsDest = info[4].As<Napi::Boolean>();

[erkinsergey]

@gms1 Thanks for the tip, it really works!

var backup = await db.backup('backup.db');
await backup.step(-1);
await backup.finish();

But for myself, I have already found a solution:

-- Get the names of all my tables
SELECT name FROM sqlite_master WHERE type ='table' AND  name NOT LIKE 'sqlite_%'
-- And after
SELECT * FROM :tableName

In this way, I get auto-generated values, such as, for example, IDs, dates, etc.