Fixed: failed to parse WHERE / GROUP BY clauses in a SELECT statement without a FROM table

[zhenghaoz]

Fixed: Failed to parse WHERE / GROUP BY clauses in a SELECT statement without a FROM table

What problem does this PR solve?

Fixed #115

Bad SQL Case:

select 1 where true;
select 1 group by 1;
select 1 having true;

Check List

Tests

• Unit test

[codecov]

Codecov Report

Merging #587 into master will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #587      +/-   ##
==========================================
+ Coverage   71.85%   71.87%   +0.01%     
==========================================
  Files          32       32              
  Lines        7899     7897       -2     
==========================================
  Hits         5676     5676              
+ Misses       1684     1682       -2     
  Partials      539      539

Impacted Files	Coverage Δ
ast/dml.go	73.96% <ø> (+0.11%)	⬆️
parser.go	70.37% <ø> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f8adf16...da2ef8b. Read the comment docs.

[kennytm]

LGTM

[tangenta]

LGTM

[tiancaiamao]

I find a problem:

Before this COMMIT:

mysql> SELECT @@autocommit limit 1;
+--------------+
| @@autocommit |
+--------------+
| 1            |
+--------------+
1 row in set (0.00 sec)

After this COMMIT:

mysql> SELECT @@autocommit limit 1;
+----------------------+
| @@autocommit limit 1 |
+----------------------+
| 1                    |
+----------------------+
1 row in set (0.00 sec)

Note the column name is different.

[zhenghaoz]

Is it casued by line 6061 in parser.y?

} else {
	lastEnd = len(src)
	if src[lastEnd-1] == ';' {
		lastEnd--
	}
}

[tiancaiamao]

The gramma change seems not right, can we have:

select 1 where true group by 1 having 1>0

[tiancaiamao]

I'm trying to fix but not sure it's better to fix, or rollback this PR first. It seems to introduce other problems.

Could you find a way to make all the tests pass in #596 @zhenghaoz