Postgres和JOOQ的不区分大小写的正则表达式？

Question

I currently use this code with JOOQ:

Condition condition = DSL.trueCondition();
if( isNotBlank(email) ){
  condition = condition.and(APP_USER.EMAIL.likeRegex(email));
}

That ends up issuing Postgres specific SQL that does the regex match in the DB:

app_user.email ~ '{email regex}'

Is it possible to get JOOQ to issue the case insensitive version: app_user.email ~* '{email regex}' ?

---

My current workaround is to use this code:

if( isNotBlank(email) ){
  condition = condition.and(
    APP_USER.EMAIL.lower().likeRegex(email.toLowerCase()) );
}

Answer 1

If ever the jOOQ API is missing vendor-specific functionality, the answer is "plain SQL" . In your case, simply write this:

PostgreSQL-specific solution

Condition condition = DSL.trueCondition();
if( isNotBlank(email) ){
  condition = condition.and("{0} ~* {1}", APP_USER.EMAIL, DSL.val(email));
}

The method Condition.and(String, QueryPart...) is just convenience for creating an explicit plain SQL Condition through DSL.condition(String, QueryPart...) :

Condition condition = DSL.trueCondition();
if( isNotBlank(email) ){
  condition = condition.and(DSL.condition("{0} ~* {1}", APP_USER.EMAIL, DSL.val(email)));
}

Vendor-agnostic solution

If you want to be vendor-agnostic, you'd have to wrap the above code in your own utility and resort to using a CustomCondition

public static Condition caseInsensitiveLikeRegex(Field<String> field, String regex) {
    return new CustomCondition() {
        @Override
        public void accept(Context<?> ctx) {
            if (ctx.family() == POSTGRES)
                ctx.visit(DSL.condition("{0} ~* {1}", field, DSL.val(regex));
            else
                ctx.visit(field.lower().likeRegex(regex.toLowerCase()));
        }
    }
}

The regex.toLowerCase() call is not 100% correct, of course, as it lower cases both the regex content, as well as the escaped patterns, such as \\B for backslash, but you get the idea.