html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app
https://github.com/simonw/datasette/issues/1151#issuecomment-767762551,https://api.github.com/repos/simonw/datasette/issues/1151,767762551,MDEyOklzc3VlQ29tbWVudDc2Nzc2MjU1MQ==,9599,2021-01-26T19:07:44Z,2021-01-26T19:07:44Z,OWNER,Mentioned in https://simonwillison.net/2021/Jan/25/datasette/,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747801751,https://api.github.com/repos/simonw/datasette/issues/1151,747801751,MDEyOklzc3VlQ29tbWVudDc0NzgwMTc1MQ==,9599,2020-12-18T01:03:39Z,2020-12-18T01:03:39Z,OWNER,"This feature is illustrated by the tests: https://github.com/simonw/datasette/blob/5e9895c67f08e9f42acedd3d6d29512ac446e15f/tests/test_internals_database.py#L469-L496

I added new documentation for the `Datasette()` constructor here as well: https://docs.datasette.io/en/latest/internals.html#database-ds-path-none-is-mutable-false-is-memory-false-memory-name-none","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747801084,https://api.github.com/repos/simonw/datasette/issues/1151,747801084,MDEyOklzc3VlQ29tbWVudDc0NzgwMTA4NA==,9599,2020-12-18T01:01:26Z,2020-12-18T01:01:26Z,OWNER,"I tested this with a one-off plugin and it worked!

```python
from datasette import hookimpl
from datasette.database import Database


@hookimpl
def startup(datasette):
    datasette.add_database(""statistics"", Database(
        datasette,
        memory_name=""statistics""
    ))
```
This created a `/statistics` database when I ran `datasette` - and if I installed https://github.com/simonw/datasette-write I could then create tables in it which persisted until I restarted the server.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747784199,https://api.github.com/repos/simonw/datasette/issues/1151,747784199,MDEyOklzc3VlQ29tbWVudDc0Nzc4NDE5OQ==,9599,2020-12-18T00:09:36Z,2020-12-18T00:09:36Z,OWNER,"Is it possible to connect to a memory database in read-only mode?

`file:foo?mode=memory&cache=shared&mode=ro` isn't valid because it features `mode=` more than once.

https://stackoverflow.com/a/40548682 suggests using `PRAGMA query_only` on the connection instead.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747775245,https://api.github.com/repos/simonw/datasette/issues/1151,747775245,MDEyOklzc3VlQ29tbWVudDc0Nzc3NTI0NQ==,9599,2020-12-17T23:43:41Z,2020-12-17T23:56:27Z,OWNER,"I'm going to add an argument to the `Database()` constructor which means ""connect to named in-memory database called X"".

```python
db = Database(ds, memory_name=""datasette"")
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747779056,https://api.github.com/repos/simonw/datasette/issues/1151,747779056,MDEyOklzc3VlQ29tbWVudDc0Nzc3OTA1Ng==,9599,2020-12-17T23:55:57Z,2020-12-17T23:55:57Z,OWNER,Wait I do use it - if you run `datasette --memory` - which is useful for trying things out in SQL that doesn't need to run against a table.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747775792,https://api.github.com/repos/simonw/datasette/issues/1151,747775792,MDEyOklzc3VlQ29tbWVudDc0Nzc3NTc5Mg==,9599,2020-12-17T23:45:20Z,2020-12-17T23:45:20Z,OWNER,"Do I use the current `is_memory=` boolean anywhere at the moment?

https://ripgrep.datasette.io/-/ripgrep?pattern=is_memory - doesn't look like it.

I may remove that feature, since it's not actually useful, and replace it with a mechanism for creating shared named memory databases instead.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747774855,https://api.github.com/repos/simonw/datasette/issues/1151,747774855,MDEyOklzc3VlQ29tbWVudDc0Nzc3NDg1NQ==,9599,2020-12-17T23:42:34Z,2020-12-17T23:42:34Z,OWNER,"This worked as a prototype:
```diff
diff --git a/datasette/database.py b/datasette/database.py
index 412e0c5..a90e617 100644
--- a/datasette/database.py
+++ b/datasette/database.py
@@ -24,11 +24,12 @@ connections = threading.local()
 
 
 class Database:
-    def __init__(self, ds, path=None, is_mutable=False, is_memory=False):
+    def __init__(self, ds, path=None, is_mutable=False, is_memory=False, uri=None):
         self.ds = ds
         self.path = path
         self.is_mutable = is_mutable
         self.is_memory = is_memory
+        self.uri = uri
         self.hash = None
         self.cached_size = None
         self.cached_table_counts = None
@@ -46,6 +47,8 @@ class Database:
                 }
 
     def connect(self, write=False):
+        if self.uri:
+            return sqlite3.connect(self.uri, uri=True, check_same_thread=False)
         if self.is_memory:
             return sqlite3.connect("":memory:"")
         # mode=ro or immutable=1?
```
Then in `ipython`:
```
from datasette.app import Datasette
from datasette.database import Database
ds = Datasette([])
db = Database(ds, uri=""file:datasette?mode=memory&cache=shared"", is_memory=True)
await db.execute_write(""create table foo (bar text)"")
await db.table_names()
# Outputs [""foo""]
db2 = Database(ds, uri=""file:datasette?mode=memory&cache=shared"", is_memory=True)
await db2.table_names()
# Also outputs [""foo""]
```

```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747770581,https://api.github.com/repos/simonw/datasette/issues/1151,747770581,MDEyOklzc3VlQ29tbWVudDc0Nzc3MDU4MQ==,9599,2020-12-17T23:31:18Z,2020-12-17T23:32:07Z,OWNER,"This works in `ipython`:
```
In [1]: import sqlite3

In [2]: c1 = sqlite3.connect(""file:datasette?mode=memory&cache=shared"", uri=True)

In [3]: c2 = sqlite3.connect(""file:datasette?mode=memory&cache=shared"", uri=True)

In [4]: c1.executescript(""CREATE TABLE hello (world TEXT)"")
Out[4]: <sqlite3.Cursor at 0x1104addc0>

In [5]: c1.execute(""select * from sqlite_master"").fetchall()
Out[5]: [('table', 'hello', 'hello', 2, 'CREATE TABLE hello (world TEXT)')]

In [6]: c2.execute(""select * from sqlite_master"").fetchall()
Out[6]: [('table', 'hello', 'hello', 2, 'CREATE TABLE hello (world TEXT)')]

In [7]: c3 = sqlite3.connect(""file:datasette?mode=memory&cache=shared"", uri=True)

In [9]: c3.execute(""select * from sqlite_master"").fetchall()
Out[9]: [('table', 'hello', 'hello', 2, 'CREATE TABLE hello (world TEXT)')]

In [10]: c4 = sqlite3.connect(""file:datasette?mode=memory"", uri=True)

In [11]: c4.execute(""select * from sqlite_master"").fetchall()
Out[11]: []
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747770082,https://api.github.com/repos/simonw/datasette/issues/1151,747770082,MDEyOklzc3VlQ29tbWVudDc0Nzc3MDA4Mg==,9599,2020-12-17T23:29:53Z,2020-12-17T23:29:53Z,OWNER,I'm going to try with `file:datasette?mode=memory&cache=shared`.,"{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,
https://github.com/simonw/datasette/issues/1151#issuecomment-747769830,https://api.github.com/repos/simonw/datasette/issues/1151,747769830,MDEyOklzc3VlQ29tbWVudDc0Nzc2OTgzMA==,9599,2020-12-17T23:29:08Z,2020-12-17T23:29:08Z,OWNER,"https://sqlite.org/inmemorydb.html

>  The database ceases to exist as soon as the database connection is closed. Every :memory: database is distinct from every other. So, opening two database connections each with the filename "":memory:"" will create two independent in-memory databases.
>
> [...]
>
> The special `"":memory:""` filename also works when using URI filenames. For example:
>
>      rc = sqlite3_open(""file::memory:"", &db);
>
> [...]
>
>  However, the same in-memory database can be opened by two or more database connections as follows:
>
>      rc = sqlite3_open(""file::memory:?cache=shared"", &db);
>
> [...]
> If two or more distinct but shareable in-memory databases are needed in a single process, then the mode=memory query parameter can be used with a URI filename to create a named in-memory database:
>
>     rc = sqlite3_open(""file:memdb1?mode=memory&cache=shared"", &db);
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",770448622,