Parse check constraints

[kyleconroy]

Feature Description

When creating a table in MySQL, a number of check constraints can be added.

CREATE TABLE t1
(
  CHECK (c1 <> c2),
  c1 INT CHECK (c1 > 10),
  c2 INT CONSTRAINT c2_positive CHECK (c2 > 0),
  c3 INT CHECK (c3 < 100),
  CONSTRAINT c1_nonzero CHECK (c1 <> 0),
  CHECK (c1 > c3)
);

The sqlparser module does not currently parse these statements.

Use Case(s)

sqlparser is being used by https://github.com/kyleconroy/sqlc, a SQL to Go code generator, and needs this information to correctly generate code from database migrations and other code using CHECK constraints.

[yindia]

@morgo Would like to work on this but I need a help.

[morgo]

@systay and @harshit-gangal are the best mentors. They are Andres Taylor and Harshit on Slack.

[supra08]

Hi @evalsocket ! Are you working on this? If not, I would like to take this up.
@morgo ?

[morgo]

@supra08 There are no open PRs that correspond to this. Let's give @evalsocket a brief moment to reply, but I think it's yours for the taking :-)

[supra08]

Alright thanks!

[ilknarf]

@supra08 have you been working on this? If not, I would love to take a crack.

[supra08]

No sorry, I haven't been working on it. You can take it up.

[ilknarf]

No sorry, I haven't been working on it. You can take it up.

Thanks for the prompt reply, I'll take a shot at it.