StackOverflowError when matching SQL query

Question

My task is to shorten a large SQL query for logging purpose. As such, I need to match a query like this:

INSERT INTO analytics_events (person_id,other_person_id,location_id,location_name,date,action,type,info,created_at,updated_at) VALUES
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')
(123, 456, 19, 'Sarasota', '2018-10-31 09:08:17.982', 'send', 'email', 'Subject: Check out this cat video', '2018-10-31 09:09:17.982', '2018-10-31 09:09:17.982'),
(321, 654, 89, 'Indianapolis', '2018-10-31 09:08:18.982', 'read', 'page', 'Title: You\'ll Never Believe What they said', '2018-10-31 09:09:19.982', '2018-10-31 09:09:19.982'),
... '9998 more rows')

My Regex code is:

Pattern.compile("INSERT(.|\\n)*INTO(.|\\n)*VALUES(.|\\n)*", Pattern.CASE_INSENSITIVE);

Unfortunately, this is causing this exception:

java.lang.StackOverflowError
    at java.util.regex.Pattern$CharProperty.match(Pattern.java:3774)
    at java.util.regex.Pattern$Branch.match(Pattern.java:4604)
    at java.util.regex.Pattern$GroupHead.match(Pattern.java:4658)
    at java.util.regex.Pattern$Loop.match(Pattern.java:4785)
    at java.util.regex.Pattern$GroupTail.match(Pattern.java:4717)

My goal is to convert this SQL text to something that has no data component, such as:

INSERT INTO analytics_events (person_id,other_person_id,location_id,location_name,date,action,type,info,created_at,updated_at)

For the purpose of aggregating timing statistics for queries.

Never use `(.|\n)*` pattern in any regex flavor. There are almost always ways to express this part in a better and more efficient way. — Wiktor Stribiżew, Nov 06 '18 at 14:26
@WiktorStribiżew, I realize this is an issue, but this question is asking for help with Regex to fix it, as I'm out of ideas — ipolevoy, Nov 06 '18 at 14:47
SQL language is not regular. Unless your queries are very specific, you should not use regex. — Wiktor Stribiżew, Nov 06 '18 at 14:55
@WiktorStribiżew, thanks for the link. This code change helped: `Pattern.compile("INSERT.*into.*VALUES.*", Pattern.DOTALL | Pattern.CASE_INSENSITIVE);` — ipolevoy, Nov 06 '18 at 14:55
Watch out for backtracking with that regex. It can become [catastrophic](https://www.regular-expressions.info/catastrophic.html). — Wiktor Stribiżew, Nov 06 '18 at 14:56
@WiktorStribiżew, thanks for the suggestion, we will follow that link! — ipolevoy, Nov 06 '18 at 15:35

StackOverflowError when matching SQL query

0 Answers0