fix: improve DDL parsing for CHECK/CONSTRAINT/FOREIGN KEY

[LouisBrunner]

• Do only one thing
• Non breaking API changes
• Tested

What did this pull request do?

Currently, the parsing of the DDL ignores some columns (if they start with check or constraint) and add ones that aren't really column (if you have a constraint without CONSTRAINT in front, which is valid). This PR focuses on supporting such cases.

FOREIGN KEY

Example: CREATE TABLE Docs (ID int NOT NULL,UserID int NOT NULL,FOREIGN KEY (UserID) REFERENCES Users(ID))

Explanation: As you don't need to have CONSTRAINT to specify a constraint, it is possible to have a DB which has been created without them and the current parser will consider that a column. This will of course fail when trying to recreate the table as the INSERT INTO () SELECT generated is invalid.

Solution: Because it contains a space, it can easily be detected, just like PRIMARY KEY.

CHECK

Example: CREATE TABLE Docs (ID int NOT NULL,Checksum text NOT NULL)

Explanation: The current parser will ignore any column which starts with CHECK, this works when it is actually a check (e.g. CHECK (Age > 25)) but fails if you just have a column that happens to be named something like checksum (which is valid).

Solution: instead of just checking for a prefix, we use a regexp to detect if something looks like CHECK ( (including any number or whitespace between CHECK and ().

CONSTRAINT

Same deal as CHECK, the only difference is the final regexp which is a bit more complex, checking that CONSTRAINT is followed by a name.

[grandwizard28]

Hi,
I just came across this PR and was wondering if you are planning to support UNIQUE as well.

The following is not being parsed correctly:

CREATE TABLE IF NOT EXISTS "users" ("id" text NOT NULL, "display_name" text NOT NULL, "email" text NOT NULL, PRIMARY KEY ("id"), UNIQUE ("email"), FOREIGN KEY ("org_id") REFERENCES "organizations" ("id"));

This PR will address FOREIGN KEY but it still won't work with UNIQUE

[LouisBrunner]

@grandwizard28 Added.

You can use

replace gorm.io/driver/sqlite v1.6.0 => github.com/aica-technology/sqlite v0.0.0-20250630152124-ead9125b9801

In your go.mod until this PR get merged.

[grandwizard28]

Awesome!