{"rowid": 348, "title": "0.32 (2019-11-14)", "content": "Datasette now renders templates using Jinja async mode . This means plugins can provide custom template functions that perform asynchronous actions, for example the new datasette-template-sql plugin which allows custom templates to directly execute SQL queries and render their results. ( #628 )", "sections_fts": 45, "rank": null} {"rowid": 435, "title": "Checking permissions in plugins", "content": "Datasette plugins can check if an actor has permission to perform an action using the datasette.permission_allowed(...) method. \n Datasette core performs a number of permission checks, documented below . Plugins can implement the permission_allowed(datasette, actor, action, resource) plugin hook to participate in decisions about whether an actor should be able to perform a specified action.", "sections_fts": 45, "rank": null} {"rowid": 123, "title": "JSON API", "content": "Datasette provides a JSON API for your SQLite databases. Anything you can do\n through the Datasette user interface can also be accessed as JSON via the API. \n To access the API for a page, either click on the .json link on that page or\n edit the URL and add a .json extension to it. \n If you started Datasette with the --cors option, each JSON endpoint will be\n served with the following additional HTTP headers: \n Access-Control-Allow-Origin: *\nAccess-Control-Allow-Headers: Authorization\nAccess-Control-Expose-Headers: Link \n This means JavaScript running on any domain will be able to make cross-origin\n requests to fetch the data. \n If you start Datasette without the --cors option only JavaScript running on\n the same domain as Datasette will be able to access the API.", "sections_fts": 45, "rank": null} {"rowid": 200, "title": "Custom pages and templates", "content": "Datasette provides a number of ways of customizing the way data is displayed.", "sections_fts": 45, "rank": null} {"rowid": 196, "title": "Release process", "content": "Datasette releases are performed using tags. When a new release is published on GitHub, a GitHub Action workflow will perform the following: \n \n \n Run the unit tests against all supported Python versions. If the tests pass... \n \n \n Build a Docker image of the release and push a tag to https://hub.docker.com/r/datasetteproject/datasette \n \n \n Re-point the \"latest\" tag on Docker Hub to the new image \n \n \n Build a wheel bundle of the underlying Python source code \n \n \n Push that new wheel up to PyPI: https://pypi.org/project/datasette/ \n \n \n To deploy new releases you will need to have push access to the main Datasette GitHub repository. \n Datasette follows Semantic Versioning : \n major.minor.patch \n We increment major for backwards-incompatible releases. Datasette is currently pre-1.0 so the major version is always 0 . \n We increment minor for new features. \n We increment patch for bugfix releass. \n Alpha and beta releases may have an additional a0 or b0 prefix - the integer component will be incremented with each subsequent alpha or beta. \n To release a new version, first create a commit that updates the version number in datasette/version.py and the the changelog with highlights of the new version. An example commit can be seen here : \n # Update changelog\ngit commit -m \" Release 0.51a1\n\nRefs #1056, #1039, #998, #1045, #1033, #1036, #1034, #976, #1057, #1058, #1053, #1064, #1066\" -a\ngit push \n Referencing the issues that are part of the release in the commit message ensures the name of the release shows up on those issue pages, e.g. here . \n You can generate the list of issue references for a specific release by copying and pasting text from the release notes or GitHub changes-since-last-release view into this Extract issue numbers from pasted text tool. \n To create the tag for the release, create a new release on GitHub matching the new version number. You can convert the release notes to Markdown by copying and pasting the rendered HTML into this Paste to Markdown tool . \n Finally, post a news item about the release on datasette.io by editing the news.yaml file in that site's repository.", "sections_fts": 45, "rank": null} {"rowid": 470, "title": "Using pip", "content": "Datasette requires Python 3.7 or higher. The Python.org Python For Beginners page has instructions for getting started. \n You can install Datasette and its dependencies using pip : \n pip install datasette \n You can now run Datasette like so: \n datasette", "sections_fts": 45, "rank": null} {"rowid": 95, "title": "max_returned_rows", "content": "Datasette returns a maximum of 1,000 rows of data at a time. If you execute a query that returns more than 1,000 rows, Datasette will return the first 1,000 and include a warning that the result set has been truncated. You can use OFFSET/LIMIT or other methods in your SQL to implement pagination if you need to return more than 1,000 rows. \n You can increase or decrease this limit like so: \n datasette mydatabase.db --setting max_returned_rows 2000", "sections_fts": 45, "rank": null} {"rowid": 211, "title": "Custom error pages", "content": "Datasette returns an error page if an unexpected error occurs, access is forbidden or content cannot be found. \n You can customize the response returned for these errors by providing a custom error page template. \n Content not found errors use a 404.html template. Access denied errors use 403.html . Invalid input errors use 400.html . Unexpected errors of other kinds use 500.html . \n If a template for the specific error code is not found a template called error.html will be used instead. If you do not provide that template Datasette's default error.html template will be used. \n The error template will be passed the following context: \n \n \n status - integer \n \n The integer HTTP status code, e.g. 404, 500, 403, 400. \n \n \n \n error - string \n \n Details of the specific error, usually a full sentence. \n \n \n \n title - string or None \n \n A title for the page representing the class of error. This is often None for errors that do not provide a title separate from their error message.", "sections_fts": 45, "rank": null} {"rowid": 220, "title": "Performance and caching", "content": "Datasette runs on top of SQLite, and SQLite has excellent performance. For small databases almost any query should return in just a few milliseconds, and larger databases (100s of MBs or even GBs of data) should perform extremely well provided your queries make sensible use of database indexes. \n That said, there are a number of tricks you can use to improve Datasette's performance.", "sections_fts": 45, "rank": null} {"rowid": 70, "title": "The Datasette Ecosystem", "content": "Datasette sits at the center of a growing ecosystem of open source tools aimed at making it as easy as possible to gather, analyze and publish interesting data. \n These tools are divided into two main groups: tools for building SQLite databases (for use with Datasette) and plugins that extend Datasette's functionality. \n The Datasette project website includes a directory of plugins and a directory of tools: \n \n \n Plugins directory on datasette.io \n \n \n Tools directory on datasette.io", "sections_fts": 45, "rank": null} {"rowid": 89, "title": "Using --setting", "content": "Datasette supports a number of settings. These can be set using the --setting name value option to datasette serve . \n You can set multiple settings at once like this: \n datasette mydatabase.db \\\n --setting default_page_size 50 \\\n --setting sql_time_limit_ms 3500 \\\n --setting max_returned_rows 2000", "sections_fts": 45, "rank": null} {"rowid": 229, "title": "Specifying units for a column", "content": "Datasette supports attaching units to a column, which will be used when displaying\n values from that column. SI prefixes will be used where appropriate. \n Column units are configured in the metadata like so: \n {\n \"databases\": {\n \"database1\": {\n \"tables\": {\n \"example_table\": {\n \"units\": {\n \"column1\": \"metres\",\n \"column2\": \"Hz\"\n }\n }\n }\n }\n }\n} \n Units are interpreted using Pint , and you can see the full list of available units in\n Pint's unit registry . You can also add custom units to the metadata, which will be\n registered with Pint: \n {\n \"custom_units\": [\n \"decibel = [] = dB\"\n ]\n}", "sections_fts": 45, "rank": null} {"rowid": 65, "title": "Enabling full-text search for a SQLite table", "content": "Datasette takes advantage of the external content mechanism in SQLite, which allows a full-text search virtual table to be associated with the contents of another SQLite table. \n To set up full-text search for a table, you need to do two things: \n \n \n Create a new FTS virtual table associated with your table \n \n \n Populate that FTS table with the data that you would like to be able to run searches against", "sections_fts": 45, "rank": null} {"rowid": 453, "title": "Running SQL queries", "content": "Datasette treats SQLite database files as read-only and immutable. This means it is not possible to execute INSERT or UPDATE statements using Datasette, which allows us to expose SELECT statements to the outside world without needing to worry about SQL injection attacks. \n The easiest way to execute custom SQL against Datasette is through the web UI. The database index page includes a SQL editor that lets you run any SELECT query you like. You can also construct queries using the filter interface on the tables page, then click \"View and edit SQL\" to open that query in the custom SQL editor. \n Note that this interface is only available if the execute-sql permission is allowed. \n Any Datasette SQL query is reflected in the URL of the page, allowing you to bookmark them, share them with others and navigate through previous queries using your browser back button. \n You can also retrieve the results of any query as JSON by adding .json to the base URL.", "sections_fts": 45, "rank": null} {"rowid": 174, "title": "CSRF protection", "content": "Datasette uses asgi-csrf to guard against CSRF attacks on form POST submissions. Users receive a ds_csrftoken cookie which is compared against the csrftoken form field (or x-csrftoken HTTP header) for every incoming request. \n If your plugin implements a