No aliases to FetchDataframeStep

[ea-rus]

Support query current_timestamp in query:

select current_timestamp from my_pg.branches

Changes:

• Render: use special functions instead of identifier
• Planner
  • don't add aliases for selects from database
  • remove alias for ts conditions, they will be copied to other TS queries

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mindsdb_sql
__about__.py	10	10	0%	1–10
__init__.py	129	23	82%	43, 47, 93, 110, 113, 134–153, 160–161, 178
mindsdb_sql/parser
lexer.py	165	1	99%	243
logger.py	19	4	79%	14, 17, 23, 26
parser.py	456	31	93%	48, 53, 73, 77, 81, 87, 91–93, 121–128, 182, 199, 249, 253, 317, 346–347, 367, 378, 491, 526, 557, 567, 581, 657
utils.py	46	4	91%	73–79
mindsdb_sql/parser/ast
base.py	36	7	81%	13, 28, 31, 49–52
create.py	70	10	86%	7–8, 21, 26, 89–94
drop.py	52	2	96%	10, 13
insert.py	62	5	92%	32, 35–37, 42
show.py	48	1	98%	18
update.py	53	5	91%	40–42, 75–76
mindsdb_sql/parser/ast/select
case.py	26	2	92%	19, 22
constant.py	36	1	97%	23
data.py	11	2	82%	15, 19
identifier.py	64	7	89%	43, 80–85
native_query.py	13	1	92%	25
operation.py	121	7	94%	27–30, 56, 65, 166, 185
parameter.py	11	1	91%	10
select.py	97	3	97%	148–153
star.py	12	2	83%	8–9
union.py	23	1	96%	18
mindsdb_sql/parser/dialects/mindsdb
create_predictor.py	92	1	99%	55
knowledge_base.py	40	1	98%	71
lexer.py	255	21	92%	336, 338, 340, 352, 354, 356, 362–380
parser.py	947	27	97%	120, 124, 263, 288, 375, 377, 568, 585, 609–610, 753, 806, 860, 877, 1006, 1016, 1054–1055, 1080, 1091, 1227, 1280, 1708, 1716, 1769–1772
mindsdb_sql/parser/dialects/mysql
lexer.py	23	6	74%	16, 18, 20, 32, 34, 36
parser.py	609	24	96%	131, 133, 226–227, 326, 356, 373, 423, 427, 501, 511, 549–550, 570, 581, 702, 730, 735–737, 741, 758, 902, 1046
show_index.py	17	11	35%	10–12, 15–23, 26–27
mindsdb_sql/planner
plan_join.py	274	12	96%	137, 173, 182, 209, 213, 302, 350, 368, 377–378, 406, 408
plan_join_ts.py	179	10	94%	53, 60, 83–84, 129, 181, 185, 193, 268, 335
query_plan.py	22	8	64%	13–21, 30
query_planner.py	387	63	84%	41–42, 65–66, 75, 152, 175, 380, 408–486, 529–530, 543, 569, 631, 661, 689, 714–716
query_prepare.py	284	61	79%	76, 78, 86–116, 227, 249, 272, 315, 336, 360, 389–443, 446–452, 483, 496–498, 507, 526
step_result.py	14	2	86%	7, 12
steps.py	180	22	88%	14, 19, 27, 32–34, 55–60, 67–73, 110–115
ts_utils.py	67	6	91%	59, 61, 83–86, 90
utils.py	242	27	89%	60, 106, 112, 127, 139, 151, 154, 166, 196, 209, 224, 230, 235, 242, 244, 249, 262, 267, 273, 279, 293, 310, 340–341, 352–353, 368
mindsdb_sql/render
sqlalchemy_render.py	414	77	81%	53, 87, 89, 101, 106, 123, 125, 127, 129, 191, 194–195, 208–209, 220–221, 239, 269, 271, 300, 314, 320, 371, 434–445, 456–460, 490, 505, 510–520, 529–530, 554–565, 584, 607–631, 639, 643, 665–668, 688–691
TOTAL	6376	509	92%

Tests	Skipped	Failures	Errors	Time
667	1 💤	0 ❌	0 🔥	21.690s ⏱️