Parser fails to handle extract() function with regex pattern: "unknown interval type" error #222
Description
DescriptionThe parser fails to parse valid ClickHouse SQL that uses the extract() function with a regex pattern, incorrectly treating it as an interval-related function.
Error Message
=== RUN TestParseSQL
parse_test.go:282: line 12:32 unknown interval type: <"instance">
when length(extract(instance, '((\\d+\\.){3}\\d+)')) > 0 then instance
^
--- FAIL: TestParseSQL (5.77s)SQL Example
SELECT
count(1), src_type, node_class, port, client_port
FROM
ocean.rt_stream_stat_15s_detail_distributed
WHERE
app_id = 999118646
AND toUnixTimestamp(timestamp) >= 1740366695
AND toUnixTimestamp(timestamp) <= 1740377495
GROUP BY
CASE
WHEN length(extract(instance, '((\\d+\\.){3}\\d+)')) > 0 THEN instance
ELSE '空'
END,
CASE
WHEN length(extract(client_ip, '((\\d+\\.){3}\\d+)')) > 0 THEN client_ip
ELSE '空'
END,
src_type,
node_class,
port,
client_port
LIMIT 10000Expected Behavior
The parser should successfully parse the SQL statement. In ClickHouse, extract(string, pattern) is used for regex extraction, not just for datetime interval extraction.
https://clickhouse.com/docs/sql-reference/functions/string-search-functions#extract
Actual Behavior
The parser throws an error: unknown interval type: <"instance">, suggesting it's trying to parse extract() as an interval/datetime function only.
Environment
- Parser version: v0.4.17
Reproducible Test Casefunc
func TestParseSQL(t *testing.T) {
sql := `select
length(extract(instance, '((\\d+\\.){3}\\d+)'))
from
rt_stream_stat_15s_detail_distributed
where
timestamp > '2025-12-05 15:00:00'
limit
10`
parser := clickhouse.NewParser(sql)
stmts, err := parser.ParseStmts()
if err != nil {
t.Error(err) // Fails with "unknown interval type" error
}
}