The main difference between = and != is how null values are handled.
SQLite passes a flag "NULLEQ" to Eq and Ne to disambiguate that.
In the presence of that flag, NULL = NULL.
Some prep work is done to make sure we can pass a flag instead of a
boolean to Eq and Ne. I looked into the bitflags crate but got a bit
scared with the list of dependencies.
Warning:
The following query produces a different result for Limbo:
```
select * from demo where value is null or id == 2;
```
I strongly suspect the issue is with the OR implementation, though. The
bytecode generated is quite different.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#847
Instead of always having the caller specify all instructions, this
work introduces convenience functions into the program builder,
making the code a lot cleaner.
Draft for now, as this is done on top of #841
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#844
The main difference between = and != is how null values are handled.
SQLite passes a flag "NULLEQ" to Eq and Ne to disambiguate that.
In the presence of that flag, NULL = NULL.
Some prep work is done to make sure we can pass a flag instead of a
boolean to Eq and Ne. I looked into the bitflags crate but got a bit
scared with the list of dependencies.
Instead of always having the caller specify all instructions, this
work introduces convenience functions into the program builder,
making the code a lot cleaner.
The error is due to comparing the PRIMARY KEY's name to INTEGER when in
it was all in lowercase. This was causing `needs_auto_index` to be set
to `true`.
After the fix:
```
/limbo /tmp/sc2-limbo.db
Limbo v0.0.13
Enter ".help" for usage hints.
limbo> CREATE TABLE temp (t1 integer, primary key (t1));
hexdump -s 28 -n 4 /tmp/sc2-limbo.db
000001c 0000 0200 -- matches SQLite
0000020
```
Closes https://github.com/tursodatabase/limbo/issues/824
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#830
The pragma list will only grow. The strum crate can be used to:
* automatically convert to string from enum
* automatically convert to enum from string
* implement an iterator over all elements of the enum
This is mostly refactoring Cursor.write_info to instead be an enum,
where one of the options is a WriteInfo. This permits one to add other
state machines to Cursor, and I added the state needed for Count as an
example, but all the testing for count's implementation depends on
ANALYZE #656 working end-to-end (to some degree) so that one can write a
SQL test for it.
But this code seems conflict-prone, so it seems better to get it in
sooner than later.
I also finally understood what the point of RefCell is from fighting
with rust on this, so that was nice.
Closes#836
Both () and = variants covered. It is important to make sure that
the transaction is a read transaction, so we cannot hide all that logic
inside update_pragma, and have to make our decision before that.
SQLite holds on to it deeply, for example:
sqlite> create table a(a int);
sqlite> create table b(b integer);
sqlite> create table c(c glauber);
sqlite> pragma table_info=a;
0|a|INT|0||0
sqlite> pragma table_info=b;
0|b|INTEGER|0||0
sqlite> pragma table_info=c;
0|c|glauber|0||0
So we'll keep it as well so we can produce the same responses.
I was baffled previously, because any time that `free` was called on a
type from an extension, it would hang even when I knew it wasn't in use
any longer, and hadn't been double free'd.
After #737 was merged, I tried it again and noticed that it would no
longer hang... but only for extensions that were staticly linked.
Then I realized that we are using a global allocator, that likely wasn't
getting used in the shared library that is built separately that won't
inherit from our global allocator in core, causing some symbol mismatch
and the subsequent hanging on calls to `free`.
This PR adds the global allocator to extensions behind a feature flag in
the macro that will prevent it from being used in `wasm` and staticly
linked environments where it would conflict with limbos normal global
allocator. This allows us to properly free the memory from returning
extension functions over FFI.
This PR also changes the Extension type to a union field so we can store
int + float values inline without boxing them.
any additional tips or thoughts anyone else has on improving this would
be appreciated 👍Closes#803
This PR closes#787. Chrono offers to format the string from an iterator
of Format Items. I created a custom iterator that only allows formatters
specified by sqlite. This approach however does not address the
inefficient way that julianday is calculated. Also, with this
implementation we avoid having to maintain a separate vendored package
for strftime that may become incompatible with Chrono in the future.
Closes#792
#739
Started adding support for `LIMIT...OFFSET...`
- New `OffsetLimit` opcode
- `OFFSET` is now supported for:
- `SELECT...LIMIT...OFFSET`
- `SELECT...GROUP BY...LIMIT...OFFSET`
- `SELECT...ORDER BY...LIMIT...OFFSET`
- Subqueries for `SELECT` statements
**In progress/todo**
- [x] Testing
- [x] Handle negative offset value
- **(will make in separate PR)** Add support for
`DELETE...LIMIT...OFFSET`
- **(will make in separate PR)** Use `limit + offset` sum register from
`OffsetLimit` to constrain number of records inserted into sorter
Closes#779
Allow us to write queries like:
SELECT name, type, sql FROM sqlite_schema where sql isnull
and
SELECT name, type, sql FROM sqlite_schema where sql not null
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#829
Closes#812
`-9223372036854775808` is `MIN_INT64`. So when we extract out the minus
and try to parse the remainder it becomes greater than MAX_INT64
(9223372036854775807) and will trigger overflow, which converts the
literal into `Real`. So we have to handle it as a special case.
Reviewed-by: Kim Seon Woo (@seonWKim)
Closes#814
Allow us to write queries like:
SELECT name, type, sql FROM sqlite_schema where sql isnull
and
SELECT name, type, sql FROM sqlite_schema where sql not null
First review #820
The function follows RFC 7386 JSON Merge Patch semantics:
* If the patch is null, the target is replaced with null
* If the patch contains a scalar value, the target is replaced with that
value
* If both target and patch are objects, the patch is recursively applied
* null values in the patch result in property removal from the target
Closes#821
Change JSON deserialization to enable json_patch implementation with
SQLite-compatible behavior:
* Preserves duplicate keys in JSON objects
* Applies patches only to the first occurrence of each key
* Trade-off: Changes key lookup from O(1) to O(n) to support duplicate
keys
* Have to be merged before json_patch() function
Closes#820
Json serialization logic was pulled from serde_json. Google's json5
serialization code was not flexible enough to allow for pretty printing
json, so I believe that the formatter design is a good layer to abstract
this logic. This refactor will trivially enable the implementation of
json_pretty function from sqlite. My other PR for json_quote, #763,
depends a tiny bit on a helper utility from the previous serialization
implementation. If this PR is considered first, I will change the code
in my other PR to account for this.
Reviewed-by: Diego Reis (@diegoreis42)
Reviewed-by: Kacper Madej (@madejejej)
Closes#771
