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.
We transform all JOIN conditions into WHERE clause terms in the query
planner. The JoinAwareConditionExpr name tries to make that point, but I
think it makes things more confusing. Let's call it WhereTerm (suggested
by Jussi).
- use new TableReference and JoinAwareConditionExpr
- add utilities for determining at which loop depth a
WHERE condition should be evaluated, now that "operators"
do not carry condition expressions inside them anymore.
TLDR: no need to call either of:
program.emit_insn_with_label_dependency() -> just call program.emit_insn()
program.defer_label_resolution() -> just call program.resolve_label()
Changes:
- make BranchOffset an explicit enum (Label, Offset, Placeholder)
- remove program.emit_insn_with_label_dependency() - label dependency is automatically detected
- for label to offset mapping, use a hashmap from label(negative i32) to offset (positive u32)
- resolve all labels in program.build()
- remove program.defer_label_resolution() - all labels are resolved in build()
Closes#438
**Fixes:**
- Return the actual primary key instead of the rowid when the primary
key is not a rowid alias
sqlite:
```
limbo> create table foo (pk TEXT PRIMARY KEY, value);
sqlite> insert into foo values ('one', 'payload');
sqlite> insert into foo values ('two', 'payload');
sqlite> select * from foo;
one|payload
two|payload
```
limbo now:
```
limbo> create table foo (pk TEXT PRIMARY KEY, value);
limbo> insert into foo values ('one', 'payload');
limbo> insert into foo values ('two', 'payload');
limbo> select * from foo;
one|payload
two|payload
```
limbo before:
```
limbo> select * from foo;
1|payload
2|payload
```
Then, discovered two issues when running the whole TCL test suite
against a copy of `testing.db` that does not have rowid aliases in the
tables:
- Fix trying to convert a Scan into an IndexSearch when the associated
Expr refers to a different instance of the same table in a self-join
- Fix `scan_loop_body_labels` being pushed to in different parts of the
codegen for Scan/Search nodes resulting in incorrect label resolutions
**Additions:**
- Add a new db `testing/testing_norowidalias.db` that is a carbon copy
of `testing/testing.db` except the `id` columns of `users` and
`products` are not rowid aliases (i.e. they are `INT PRIMARY KEY`
instead of `INTEGER PRIMARY KEY`
- Run all TCL tests against both test databases with `do_execsql_test`
```
(testing/testing.db) Running test: coalesce-from-table
(testing/testing_norowidalias.db) Running test: coalesce-from-table
(testing/testing.db) Running test: coalesce-from-table-column
(testing/testing_norowidalias.db) Running test: coalesce-from-table-column
(testing/testing.db) Running test: coalesce-from-table-multiple-columns
(testing/testing_norowidalias.db) Running test: coalesce-from-table-multiple-columns
(testing/testing.db) Running test: glob-fn
(testing/testing_norowidalias.db) Running test: glob-fn
(testing/testing.db) Running test: where-glob
(testing/testing_norowidalias.db) Running test: where-glob
(testing/testing.db) Running test: where-glob-question-mark
(testing/testing_norowidalias.db) Running test: where-glob-question-mark
```
- Allow running tests against specific db file with
`do_execsql_test_on_specific_db $path`
- Wondering if I should add a new table with e.g. text primary key and
add some db-specific tests on that table...?
Closes#449
