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javamysqldatabasejooq

In jooq, how do I add an "and" condition when don't know whether there is a "where" prior to it or not?

I have the following Jooq code:

if (...) {
    query = query.where(...);
}

query = query.and(...);

The problem is that I don't know whether the where() statement will be added or not.

If not, the and() part will be added without a prior where(), which should be wrong.

I am wondering how to solve that.

Must I write it as follows?

if (...) {
    query = query.where(...);
}
else {
    query = query.where(true);    // This will make sure there is always a where statement, but it looks hacky...
}

query = query.and(...);

Or, must I adjust the statements' order?

What if I want to keep the order?

Thanks!

Solution

  • Don't create dynamic queries. Create dynamic conditions.

    As always, assuming this static import:

    import static org.jooq.impl.DSL.*;

    Imperative style

    Condition condition = noCondition();

// And then
if (something1)
    condition = condition.and(c1);

if (something2)
    condition = condition.and(c2);

ctx.select(...)
   .from(...)
   .where(condition)
   .fetch();

    Expression style

    ctx.select(...)
   .from(...)
   .where(something1 ? c1 : noCondition())
   .and(something2 ? c2 : noCondition())

    Functional style

    ctx.select(...)
   .from(...)
   .where(Stream
       .of(1, 2, 3)
       .map(BOOK.ID::eq)
       .reduce(noCondition(), Condition::or))
   .fetch();

    There are probably many other styles. See also: