For large tables, counting the number of rows in the table can take a
significant amount of time. Instead, where an inspect-file is provided
for an immutable database, look up the row-count for a plain count(*).
Thanks, @kevindkeogh
Queries with reserved words or characters according to the SQLite
FTS5 query language could cause errors.
Queries are now escaped like so:
dog cat => "dog" "cat"
The index page now only shows row counts for immutable databases OR for
databases with less than 30 tables provided it could get a count for
each of those tables in less than 10ms.
Closes#467, Refs #460
If we have less than 5 tables we now also show one or more views in the
summary on the homepage.
Also corrected the logic for the row counts - we now count hidden and
visible tables separately.
Closes#373, Refs #460
I've run the black code formatting tool against everything:
black tests datasette setup.py
I also added a new unit test, in tests/test_black.py, which will fail if the code does not
conform to black's exacting standards.
This unit test only runs on Python 3.6 or higher, because black itself doesn't run on 3.5.
Datasette previously only supported one type of faceting: exact column value counting.
With this change, faceting logic is extracted out into one or more separate classes which can implement other patterns of faceting - this is discussed in #427, but potential upcoming facet types include facet-by-date, facet-by-JSON-array, facet-by-many-2-many and more.
A new plugin hook, register_facet_classes, can be used by plugins to add in additional facet classes.
Each class must implement two methods: suggest(), which scans columns in the table to decide if they might be worth suggesting for faceting, and facet_results(), which executes the facet operation and returns results ready to be displayed in the UI.
Also introduced a mechanism whereby table counts are calculated against a time limit
but immutable databases have their table counts calculated on server startup.
Prior to this commit Datasette would calculate the content hash of every
database and redirect to a URL containing that hash, like so:
https://v0-27.datasette.io/fixtures => https://v0-27.datasette.io/fixtures-dd88475
This assumed that all databases were opened in immutable mode and were not
expected to change.
This will be changing as a result of #419 - so this commit takes the first step
in implementing that change by changing this default behaviour. Datasette will
now only redirect hash-free URLs under two circumstances:
* The new `hash_urls` config option is set to true (it defaults to false).
* The user passes `?_hash=1` in the URL
If you start Datasette with no files, it will connect to :memory: instead.
When starting it with files you can add --memory to also get a :memory: database.
