Expose ValueBracketReg

[hexadecy]

Fix #659

[coveralls]

Pull Request Test Coverage Report for Build 159

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+4.9%) to 73.304%

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Totals
Change from base Build 155:	4.9%
Covered Lines:	1178
Relevant Lines:	1607

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💛 - Coveralls

[arp242]

I'm not sure if I follow what this fixes exactly; your issue doesn't really mention what the problem is? It would be helpful if you could expand on that.

I also wonder if this is something that can't be fixed better instead of letting people override some mysterious regexp? Your solution is also racy and people will run in to problems if they use sqlx in more than on goroutine.

[hexadecy]

With the current regexp

var valueBracketReg = regexp.MustCompile(`\([^(]*\?+[^)]*\)`)

and with this sql request:

INSERT INTO data (map_id, coordinates) VALUES (:map_id, GeomFromEWKB(:coordinates))

we have this error:

pq: syntax error at end of input

Possible solution

Another possible fix is to have a more permissive regexp for any functions not just GeomFromEWKB(), but I not sure of the security issue (sql injection). So I think, we can at least go back to the previous behavior, cause right now we are stuck using an older version or making a fork with this small fix.

[hexadecy]

@arp242 I updated the issue to give more info.

[hexadecy]

Fix in #734