How to implement order by field value with jOOQ's dynamic queries

Question

I am trying to convert something like this in jOOQ:

select foo from bar
order by field(foo, 'value1', 'something-else', 'value3')

on a select query, like:

SelectQuery<Record> query = ...
query.addSelect(BAR.FOO);
query.addFrom(BAR);
query.addOrderBy( ... ? ... )

How does one add the last bit?

---

Background

What I am trying to accomplish is basically described here: MySQL - ORDER BY values within IN() . In my case, I have a generic batch load function that uses 'where field in(..)' and I want to preserve order. This works as I need it to using plain SQL, but I need to add this bit to a dynamically constructed query with jOOQ.

Answer 1

Whenever you hit jOOQ's limits, resort to plain SQL . You can write your own field function like this:

class MyDSL {

    public static Field<Integer> field(Field<String> search, String in1) {
        return field(search, DSL.val(in1));
    }

    public static Field<Integer> field(Field<String> search, Field<String> in1) {
        return DSL.field("field({0}, {1})", Integer.class, search, in1);
    }

    public static Field<Integer> field(Field<String> search, 
                                       String in1, 
                                       String in2) {
        return field(search, val(in1), val(in2));
    }

    public static Field<Integer> field(Field<String> search, 
                                       Field<String> in1, 
                                       Field<String> in2) {
        return DSL.field("field({0}, {1}, {2})", Integer.class, search, in1, in2);
    }

    // ... or, support a varargs function variant, too
}

And now use that in all your statements:

query.addOrderBy( MyDSL.field(BAR.FOO, "value1", "something-else", "value3") );

Answer 2

This seems to do the trick. Not sure if there is a better answer,

Field[] args = new Field[]{DSL.field("foo"), 
      DSL.val("value1"), DSL.val("something-else"), DSL.val("value3")}
query.addOrderBy(DSL.function("field", SQLDataType.INTEGER, args));

Answer 3

You can use something like to convert following sql to jooq. Here 'sortAsc' is used to sort according to the given value order.

SQL

select foo from bar order by field(foo, 'value1', 'something-else', 'value3')

JOOQ

DSL()
.select(BAR.FOO)
.from(BAR)
.orderBy(BAR.FOO.sortAsc('value11', 'something-else', 'value3'))
.fetch()