* Test for cross-database join, refs #283
* Warn if --crossdb used with more than 10 DBs, refs #283
* latest.datasette.io demo of --crossdb joins, refs #283
* Show attached databases on /_memory page, refs #283
* Documentation for cross-database queries, refs #283
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.
Also added support for descriptions and HTML descriptions.
Here's an example metadata.json file illustrating custom per-database and per-
table metadata:
{
"title": "Overall datasette title",
"description_html": "This is a <em>description with HTML</em>.",
"databases": {
"db1": {
"title": "First database",
"description": "This is a string description & has no HTML",
"license_url": "http://example.com/",
"license": "The example license",
"queries": {
"canned_query": "select * from table1 limit 3;"
},
"tables": {
"table1": {
"title": "Custom title for table1",
"description": "Tables can have descriptions too",
"source": "This has a custom source",
"source_url": "http://example.com/"
}
}
}
}
}
Closes#165, Refs #164
This means you can provide a custom base.html template that populates
extra_head and any of the default child templates will still render content
you included in that block.
Refs #158
Named canned queries can now be defined in metadata.json like this:
{
"databases": {
"timezones": {
"queries": {
"timezone_for_point": "select tzid from timezones ..."
}
}
}
}
These will be shown in a new "Queries" section beneath "Views" on the database page.
As part of this, I refactored the logic for the database index page. It used
to combine the functionality for listing available tables and the
functionality for executing custom SQL queries in a single template and view.
I have split that template out into database.html and query.html and reworked
the view to more clearly separate the custom SQL executing code.
Refs #20
Refs #153
Every template now gets CSS classes in the body designed to support custom
styling.
The index template (the top level page at /) gets this:
<body class="index">
The database template (/dbname/) gets this:
<body class="db db-dbname">
The table template (/dbname/tablename) gets:
<body class="table db-dbname table-tablename">
The row template (/dbname/tablename/rowid) gets:
<body class="row db-dbname table-tablename">
The db-x and table-x classes use the database or table names themselves IF
they are valid CSS identifiers. If they aren't, we strip any invalid
characters out and append a 6 character md5 digest of the original name, in
order to ensure that multiple tables which resolve to the same stripped
character version still have different CSS classes.
Some examples (extracted from the unit tests):
"simple" => "simple"
"MixedCase" => "MixedCase"
"-no-leading-hyphens" => "no-leading-hyphens-65bea6"
"_no-leading-underscores" => "no-leading-underscores-b921bc"
"no spaces" => "no-spaces-7088d7"
"-" => "336d5e"
"no $ characters" => "no--characters-59e024"
If someone executes 'select * from table' against a table with a million rows
in it, we could run into problems: just serializing that much data as JSON is
likely to lock up the server.
Solution: we now have a hard limit on the maximum number of rows that can be
returned by a query. If that limit is exceeded, the server will return a
`"truncated": true` field in the JSON.
This limit can be optionally controlled by the new `--max_returned_rows`
option. Setting that option to 0 disables the limit entirely.
Closes#69
Simon Willison