This PR is extracted from the sqlite fuzzing exploration effort in
https://github.com/tursodatabase/limbo/pull/1021
---
We were not evaluating constant conditions (e.g '1 IS NULL') when there
were no tables referenced in the query, because our WHERE term
evaluation was based on "during which loop" to evaluate them. However,
when there are no tables, there are no loops, so they were never
evaluated.
Closes#1023
We were not evaluating constant conditions (e.g '1 IS NULL')
when there were no tables referenced in the query, because
our WHERE term evaluation was based on "during which loop"
to evaluate them. However, when there are no tables, there are
no loops, so they were never evaluated.
Align `substr` implementation with SQLite spec
(https://www.sqlite.org/lang_corefunc.html#substr):
> The substr(X,Y,Z) function returns a substring of input string X that
begins with the Y-th character and which is Z characters long. If Z is
omitted then substr(X,Y) returns all characters through the end of the
string X beginning with the Y-th. The left-most character of X is number
1. If Y is negative then the first character of the substring is found
by counting from the right rather than the left. If Z is negative then
the abs(Z) characters preceding the Y-th character are returned. If X is
a string then characters indices refer to actual UTF-8 characters. If X
is a BLOB then the indices refer to bytes.
Reviewed-by: Jussi Saurio (@jussisaurio)
Closes#1013
After reading the fine print, SQLite documentation explains that `BEGIN
IMMEDIATE` and `BEGIN EXCLUSIVE` are the same thing in WAL mode:
https://www.sqlite.org/lang_transaction.html
As that's the only mode we support, let's just add code generation for
`BEGIN EXCLUSIVE`.
Fixes#1002Closes#1003
After reading the fine print, SQLite documentation explains that `BEGIN
IMMEDIATE` and `BEGIN EXCLUSIVE` are the same thing in WAL mode:
https://www.sqlite.org/lang_transaction.html
As that's the only mode we support, let's just add code generation for
`BEGIN EXCLUSIVE`.
Fixes#1002
Adds initial limited support for CTEs.
- No MATERIALIZED
- No RECURSIVE
- No named CTE columns
- Only SELECT statements supported inside CTE
Basically this kind of WITH clause can just be rewritten as a subquery,
so this PR adds some plumbing to rewrite them using the existing
subquery machinery.
It also introduces the concept of a `Scope` where a child query can
refer to its parent, useful for CTEs like:
```
do_execsql_test nested-subquery-cte {
with nested_sub as (
select concat(name, '!!!') as loud_hat
from products where name = 'hat'
),
sub as (
select upper(nested_sub.loud_hat) as loudest_hat from nested_sub
)
select sub.loudest_hat from sub;
} {HAT!!!}
```
I think we need to expand the use of `Scope` to all of our identifier
resolutions (currently we don't explicitly have logic for determining
what a given query can see), but I didn't want to bloat the PR too much.
Hence, this implementation is probably full of all sorts of bugs, but
I've added equivalent tests for ALL the existing subquery tests,
rewritten in CTE form.
Closes#920
Add fuzz test for string functions and fix 2 bugs in implementation of
`LTRIM/RTRIM/TRIM` and `QUOTE`:
- `QUOTE` needs to escape internal quote(`'`) symbols
- `LTRIM`/`RTRIM`/`TRIM` needs to check if they have additional argument
Closes#958
Fix codegen for `CAST` expression and also adjust implementation of
`CAST: Real -> Int` because `SQLite` use "closest integer between the
REAL value and zero" as a CAST result.
Closes#956
Add `COALESCE` function in fuzz test and fix bug (found by fuzzer with
`COALESCE`) related to the resolution of labels which needs to be
resolved to next emitted instruction.
Before, code assumed that no two labels will need to be resolved to next
emitted instruction. But this assumption is wrong (at least in current
codegen logic) for example for following expression `COALESCE(0,
COALESCE(0, 0))`. Here, both `COALESCE` functions will create label and
resolve it to next emitted instruction in the end of generation. So, in
this case one of the labels will be actually "orphaned" and never be
assigned any position in the emitted code.
Closes#955
(after fixing complicated b-tree bugs - I want to end my day with the
joy of fixing simple bugs)
This PR fix bug in emit (which was introduced after switch from
`HashMap` to `Vec`) and also align `CASE` codegen in case of `NULL`
result from `WHEN` clause with SQLite behaviour.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#953
Hi! This is my first PR on the project, so I apologize if I did not
follow a convention from the project.
#127
This PR implements json_quote as specified in their source:
https://www.sqlite.org/json1.html#jquote. It follows the internal doc
guidelines for implementing functions. Most tests were added from sqlite
test suite for json_quote, while some others were added by me. Sqlite
test suite for json_quote depends on json_valid to test for correct
escape control characters, so that specific test at the moment cannot be
done the same way.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Reviewed-by: Sonny (@sonhmai)
Closes#763
**Core delete tasks**:
- [x] Implement free page functionality
- [x] Clear overflow pages if any before deleting their cells using free
page.
- [x] Implement delete for leaf page
- [ ] Balance after delete properly
**Auxiliary tasks to make delete work properly**:
- [x] Implement block coalescing in `free_cell_range` to reduce
fragmentation.
- [x] Track page fragmentation in `free_cell_range`.
- [x] Update page offsets in `drop_cell` and update cell pointer array
after dropping a cell.
- [x] Add TCL tasks
Closes#455
--------
I will add support for balancing after delete once `balance_nonroot` is
extended. In the current state of `balance_nonroot` balancing won't work
after delete and corrupts page.
But delete itself is functional now.
Closes#785
Add basic printf function support in limbo
Closes#886
