Subquery with date: No overload matches this call

Hi, I need help once more… I’m trying to create a subquery with a datetime column.

This is the table definition:

export const tMessage = new class TMessage extends Table<DBConnection, 'TMessage'> {
    public uid = this.autogeneratedPrimaryKey<u64>('uid', 'custom', CUSTOM_TYPES.UID_MESSAGE);
    public processedAt = this.column('processedAt', 'localDateTime');
}

I want to select all messages, where the processedAt is smaller or equal to the processedAt of a message with a certain uid.

this._db
    .selectFrom(tMessage)
    .select({
        uid: tMessage.uid,
        processedAt: tMessage.processedAt,
    })
    .where(
        tMessage.processedAt.lessOrEquals(
            // Subquery
            this._db
                .selectFrom(tMessage)
                .where(tMessage.uid.equals(referenceUid))
                .selectOneColumn(tMessage.processedAt),
        ),
    )
    .orderBy('processedAt', 'asc')
    .limit(limit)
    .executeSelectMany()

However, this fails:

No overload matches this call.
...
Argument of type 'GroupByOrderByExecutableSelectExpression<DB<"DBConnection">, TMessage, undefined, Date, NoTableOrViewRequiredView<DB<"DBConnection">>, "result">' is not assignable to parameter of type 'Date'.
Argument of type 'GroupByOrderByExecutableSelectExpression<DB<"DBConnection">, TMessage, undefined, Date, NoTableOrViewRequiredView<DB<"DBConnection">>, "result">' is not assignable to parameter of type 'IComparableValueSource<TableOrViewRef<DB<"DBConnection">>, Date>'.
Argument of type 'GroupByOrderByExecutableSelectExpression<DB<"DBConnection">, TMessage, undefined, Date, NoTableOrViewRequiredView<DB<"DBConnection">>, "result">' is not assignable to parameter of type 'IComparableValueSource<TableOrViewRef<DB<"DBConnection">>, Date | null | undefined>'.

Is this because the subquery may return undefined, and undefined cannot be compared to a Date column?

[juanluispaz]

I’m making this test:

create table test(id numeber, value number);

insert into test values(1, 10);
insert into test values(2, 20);
insert into test values(3, 30);
insert into test values(4, 40);
insert into test values(5, 50);

select * from test where value < (select value from test where id = 3);

It works on Sqlite, I’m so surprised, I didn’t expect it 😄; that is not clearly documented in the sqlite documentation. I’m going to continue investigating if all other databases have the same feature. For sure this case must be in the library.

Regarding the case you describes, you can use a left join.

If you want to get all messages only if the referenceUid exists the previous query is valid for you (I updated because I used the wrong join):

const reference = tMessage.as('reference')

this._db
    .selectFrom(tMessage)
    .join(reference).on(reference.uid.equals(referenceUid))
    .select({
        uid: tMessage.uid,
        processedAt: tMessage.processedAt,
    })
    .where(
        tMessage.processedAt.lessOrEquals(reference.processedAt)
    )
    .orderBy('processedAt', 'asc')
    .limit(limit)
    .executeSelectMany()

But if you want to get all the messages in the case of the referenceUid doesn’t exists this can works for you:

const reference = tMessage.forUseInLeftJoinAs('reference')

this._db
    .selectFrom(tMessage)
    .leftJoin(reference).on(reference.uid.equals(referenceUid))
    .select({
        uid: tMessage.uid,
        processedAt: tMessage.processedAt,
    })
    .where(
        tMessage.processedAt.lessOrEquals(reference.processedAt)
    ).or(
        reference.processedAt.isNull()
    )
    .orderBy('processedAt', 'asc')
    .limit(limit)
    .executeSelectMany()

[threema-danilo]

Great, thank you @juanluispaz!