java - Create SQLite inmemory database from bytearray

Question

I need to process data from a SQLite database using some Java code. The problem is that the database is retrieved from an external service and thus it is only available as an InputStream.

I would really like to avoid saving the db to the file system before starting to process the data, but I don't see a way of doing it.

I am currently using SqlJet, as it provides an option to create an in-memory database. However there seems to be no way to turn an InputStream / byte array into a database.

There's nothing forcing me to use SqlJet, it can be easily replaced by any other tool if it provides the needed functionality.

Answer 1

It can't be done as such. Perhaps Java supports some mechanism to create some form of virtual file that is presented locally (to the current process) as some physical file.

I can think of one way to work-around the limitation, but that may not be doable or acceptable within your context. You can change the service to return a dump of the database and load that in the receiver's in-memory database:

Here is a way to generate the dump:

# sqlite3
SQLite version 3.7.11 2012-03-20 11:35:50
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> create table foo (i text);
sqlite> insert into foo values ('a');
sqlite> insert into foo values ('b');
sqlite> .dump
PRAGMA foreign_keys=OFF;
BEGIN TRANSACTION;
CREATE TABLE foo (i text);
INSERT INTO foo VALUES('a');
INSERT INTO foo VALUES('b');
COMMIT;