id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,pull_request,body,repo,type,active_lock_reason,performed_via_github_app,reactions,draft,state_reason
640330278,MDU6SXNzdWU2NDAzMzAyNzg=,851,Having trouble getting writable canned queries to work,3243482,closed,0,,,1,2020-06-17T10:30:28Z,2020-06-17T10:33:25Z,2020-06-17T10:32:33Z,CONTRIBUTOR,,"Hey,

I'm trying to get canned inserts to work. I have an DB with following metadata:

```text
sqlite> .mode line

sqlite> select name, sql from sqlite_master where name like '%search%';
 name = search
  sql = CREATE TABLE ""search"" (""id"" INTEGER NOT NULL PRIMARY KEY, ""name"" VARCHAR(255) NOT NULL, ""url"" VARCHAR(255) NOT NULL)
```

```yaml
# ...
queries:
    add_search:
        sql: insert into search(name, url) VALUES (:name, :url),
        write: true
```
which renders a form as expected, but when I submit the form I get `incomplete input` error.

![image](https://user-images.githubusercontent.com/3243482/84885285-7f46fe80-b09b-11ea-8a05-92c8986bbf7a.png)

but when submit post the form

I've attached a debugger to see where the error comes from, because `incomplete input` string doesn't appear in datasette codebase.

Inside `datasette.database.Database.execute_write_fn` 

https://github.com/simonw/datasette/blob/4fa7cf68536628344356d3ef8c92c25c249067a0/datasette/database.py#L69

```py
result = await reply_queue.async_q.get()
```

this line raises an exception. 

That led me to believe I had something wrong with my SQL. But running the command in `sqlite3` inserts the record just fine.

```text
sqlite> insert into search (name, url) values ('my name', 'my url');
sqlite> SELECT last_insert_rowid();
last_insert_rowid() = 3
```

So I'm a bit lost here.

---
- datasette, version 0.44
- Python 3.8.1",107914493,issue,,,"{""url"": ""https://api.github.com/repos/simonw/datasette/issues/851/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed