Exception message for multiple statements in single query

[ea-rus]

If string contain several statement it returns message about it:

-- Step 1: Identify all customers in the 'BUILDING' segment
SELECT c_custkey, c_name FROM tpch_pg_conn.customer WHERE c_mktsegment = 'BUILDING';
-- Step 2: Link these customers to their orders
-- (Checking if any supplier or part reference exists in orders table)
SELECT * FROM tpch_pg_conn.orders LIMIT 5;

response will be

>  SELECT c_custkey, c_name FROM tpch_pg_conn.customer WHERE c_mktsegment = 'BUILDING';
--------------------------------------------------------------------------------------^
Only a single sql statement is expected. Got multiple instead

Also queries with leading comments used to raise before, fixed in this PR

select 1; -- my query

Fixes: https://linear.app/mindsdb/issue/FQE-2076/agents-agent-streaming-failed-problem-with-final-query-syntax-error

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
mindsdb_sql_parser
__about__.py	10	10	0%	1–10
__init__.py	132	22	83%	49, 53, 58, 103, 120, 144–163, 170–171
lexer.py	287	21	93%	378, 380, 382, 394, 396, 398, 404–422
logger.py	19	4	79%	14, 17, 23, 26
parser.py	1129	29	97%	130, 134, 306, 331, 437, 624, 641, 665–666, 895, 949, 1026, 1186, 1196, 1265, 1276, 1359, 1435, 1474, 1510, 1707–1708, 1887–1888, 2064, 2072, 2125–2128
utils.py	100	12	88%	73–79, 124, 140, 142, 144, 150–153, 161
mindsdb_sql_parser/ast
base.py	36	5	86%	13, 28, 31, 46, 51
create.py	82	9	89%	7–8, 23–31, 95
drop.py	52	2	96%	10, 13
insert.py	63	4	94%	39–41, 46
show.py	48	1	98%	18
update.py	53	5	91%	40–42, 75–76
mindsdb_sql_parser/ast/mindsdb
knowledge_base.py	127	3	98%	79, 118, 128
mindsdb_sql_parser/ast/select
case.py	37	1	97%	22
constant.py	36	1	97%	23
data.py	11	4	64%	10–12, 15, 19
identifier.py	73	11	85%	47, 94–102, 112
native_query.py	13	1	92%	25
operation.py	139	4	97%	57, 66, 178, 202
parameter.py	15	1	93%	20
select.py	108	3	97%	160–165
star.py	12	2	83%	8–9
TOTAL	3505	155	96%

Tests	Skipped	Failures	Errors	Time
329	0 💤	0 ❌	0 🔥	13.925s ⏱️

[StpMax]

fail in new version:

sql = 'select "--x"'
ast = parse_sql(sql)

sql = "select '--x'"
ast = parse_sql(sql)

[ea-rus]

updated code, the trialed semicolon is omitted in different way (as a token after lexer parsed input string)

[entelligence-ai-pr-reviews]

Duplicate Code: ⚠️ Duplicate Code Detected (Similarity: 85%)

This function semicolon_checker duplicates existing code.

📍 Original Location:

mindsdb_sql_parser/__init__.py:169-187 (specifically line 175)

Function: parse_sql (semicolon removal logic)

💡 Recommendation:
Keep the existing regex approach as it's more concise (1 line vs 10 lines), more performant (no token iteration overhead), and easier to maintain. Unless there's a specific requirement for token-level semicolon handling (e.g., distinguishing between statement-separating semicolons vs trailing semicolons), the simpler regex approach should be preferred.

Consider importing and reusing the existing function instead of duplicating the logic.

[entelligence-ai-pr-reviews]

Duplicate Code: ⚠️ Duplicate Code Detected (Similarity: 95%)

This function test_trailing_semicolon duplicates existing code.

📍 Original Location:

tests/test_base_sql/test_base_sql.py:8-13

Function: test_ending

💡 Recommendation:
Consolidate into a single comprehensive test. Either enhance the existing test_ending to also validate AST structure, or replace it with the PR's test_trailing_semicolon which has a clearer name. Do NOT keep both tests as they provide redundant coverage.

Consider importing and reusing the existing function instead of duplicating the logic.