Re: the IN clause saga

>
>
>Here are the permutations I can remember:
>
>Option 1: add a method to PGStatement that explicitly sets an IN clause,
> taking either a java.sql.Array, java.util.Collection + component type,
> array + component type, or a custom postgresql object
>
> + there's no confusion as to what it means
> + using a custom object allows access via setObject(..., Types.OTHER)
> consistently, as well as via the extension method.
>
it doesn't (at least, not in the current implementation) - Types.OTHER
ends up calling setString(), that makes it useless for IN parameters

> - java.sql.Array and java.util.Collection have problems as PGStatement is
> compiled for all JDKs and JDBC versions and those types may not be present
> (we could do a PGJDBC2Statement or something, but that's getting messy)
>
you could declare it to take Object, I suppose (that would be the only
way anyway if you wanted to support arrays of primitive types anyway)

> - have to downcast to a PGStatement to use it
>
>
>
>
>Option 2: make setArray() expand to an IN clause when the parameter follows " IN".
>
> + no new methods or types needed
> - setArray() behaves differently depending on query context
> - user has to wrap the underlying array in a java.sql.Array
>
>Option 3: make setObject(n, Collection [, type]) expand to an IN clause.
>
> + no new methods or types needed
> - must assume that the contents of the collection use the default type mapping
> if a type is not provided
>
You can require the type to be provided.

> - if a type is provided and we apply it to the *components* of the
> collection, this breaks the general getObject() interface of "bind this
> object interpreting it as this particular type".
> - not obvious what to do with objects that are both Collections and some
> other SQL-relevant type; solutions make setObject's behaviour complex
> and/or query-context-dependent
>
>

>Option 4: as 3, but use java arrays (native arrays, not java.sql.Array) instead of
> java.util.Collection
>
> + as 3, but the ambiguity of "object is both Collection and SQL type X"
> goes away.
>
>Option 5: don't provide an extension at all i.e. do away with setting IN clauses
> in this way.
>
> + no issues with server-side prepare
> - obviously, you can't set IN clauses in one go any more.
>
>1-4 all need to disable server-side prepare when used.
>
>Did I miss anything? My personal order of preference is 1-2-4-5-3.
>
For what it's worth, mine is 3-4-1,2,5 (commas meaning that the last
three seem equally useless).

Dima

> I have a
>partial implementation of 2 written but it's easy to adapt that to whatever
>external interface.
>
>setArray() needs fixing regardless of what happens here. I hope to have a
>patch for that ready later today.
>
>-O
>
>---------------------------(end of broadcast)---------------------------
>TIP 2: you can get off all lists at once with the unregister command
> (send "unregister YourEmailAddressHere" to majordomo(at)postgresql(dot)org)
>
>