![]() The relevant data types here are time, date, and timestamp-where the latter has a without time zone and a with time zone variant. It deals with the basic business of representing moments (when things happen) against the background that, for example, different participants in a live international conference call see that their clocks read different times when the call starts and ends from what other participants see. This is the first of a two part blog post series. I hope that my write-up will complement the PostgreSQL documentation and help you with your task. This subsection gives you the links to the accounts of that minimal subset of functionality.īut if you have to maintain an extant application whose developers are long gone, and that has little or no developer-oriented documentation, then you will have to study the whole topic. If your aim is to write a brand new database application, then you need to understand only what is sufficient for this-and it’s a remarkably small fraction of everything that there is to know in this space. They also provide far more functionality than a correct implementation will need-which surplus serves only to give you enough rope to hang yourself.PostgreSQL, and therefore YugabyteDB, give you sufficient functionality to let you straightforwardly and correctly meet any requirement that might be set in the date-time space. ![]() The exercise left me with these two high-level conclusions: I had no choice but to aim for total understanding-complete in breadth and depth. I recently completed a careful and exhaustive study of the topic so that I could write it all up in YugabyteDB’s YSQL documentation. So some YSQL users will find the topic challenging, too. YugabyteDB’s YSQL subsystem gives the application developer the same experience as PostgreSQL. Even experienced developers struggle when they first embark on a critical project that relies on this functionality. I did not have the case of a circular dependency, I guess you can suspend temporarily the key checking if that is the case.Anecdotal reports indicate that some PostgreSQL programmers are daunted by the date and time data types, and by how operations that use values of these data types might be affected by the session’s timezone setting. Now you can try to load the resulting csv with PostgreSQL (even graphically with the admin tool), with the only caveat that you must load the tables with foreign keys after you have loaded the tables with the corresponding source keys. This works like a charm, is easy to write, read and debug each function, unlike (for me) the regular expressions. #df = other_transform(df, other_column_name)ĭf.to_csv(table_name + '.csv'), sep=',', header=False, index=False) Suppose you have a table with a bool field (which is 0/1 in sqlite, but must be t/f in PostgreSQL) def int_to_strbool(df, column):ĭf = pd.read_sql(f'select * from ', conn)ĭf = int_to_strbool(df, bool_column_name) ![]() I have tried editing/regexping the sqlite dump so PostgreSQL accepts it, it is tedious and prone to error.įirst recreate the schema on PostgreSQL without any data, either editing the dump or if you were using an ORM you may be lucky and it talks to both back-ends (sqlalchemy, peewee. To prove the concept I dumped this testdb and imported into a development environment on a production server and the data transferred over nicely. I know if I had tried to run one of these scripts or do the stepwise conversion mentioned herein, I would have spent much more time. I then created a testdb with createdb:Īfter some queries to check the data, it appears it worked quite well. Set work_mem to '16MB', maintenance_work_mem to '512 MB' With include drop, create tables, create indexes, reset sequences I installed from the *.deb and created a command file like this in a test directory: load database You can convert the flat SQLite file into a usable PostgreSQL database. Pretty cool application and it's relatively easy to use. I looked up the wiki docs:Īnd discovered pgloader. I started looking into the solutions here and realized that I was looking for a more automated method. Even though this post has an accepted answer (and a good one at that +1), I think adding this is important. I came across this post when searching for a way to convert an SQLite dump to PostgreSQL. Importing a big pile of data through SQL INSERTs might take a while but it'll work. The syntax in the SQLite dump file appears to be mostly compatible with PostgreSQL so you can patch a few things and feed it to psql. While SQLite defaults null values to '', PostgreSQL requires them to be set as NULL. You should be able to feed that dump file straight into psql: /path/to/psql -d database -U username -W 0)
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