Update with join

[saulortega]

Hello.

sqlboiler is ignoring the qm.InnerJoin() when Update. there should be support for this: https://stackoverflow.com/questions/7869592/how-to-do-an-update-join-in-postgresql

I tried adding a few lines to query_builders.go.

I changed this:

func buildUpdateQuery(q *Query) (*bytes.Buffer, []interface{}) {
    buf := strmangle.GetBuffer()

    //Code ommited...
    fmt.Fprintf(buf, " SET %s", strings.Join(setSlice, ", "))

    where, whereArgs := whereClause(q, len(args)+1)
    //Code ommited...

    return buf, args
}

for this:

func buildUpdateQuery(q *Query) (*bytes.Buffer, []interface{}) {
    buf := strmangle.GetBuffer()

    //Code ommited...
    fmt.Fprintf(buf, " SET %s", strings.Join(setSlice, ", "))

    // --------------------- START NEW LINES -------------------
    if len(q.joins) > 0 {
        joinBuf := strmangle.GetBuffer()
        for _, j := range q.joins {
            fmt.Fprintf(joinBuf, " %s", j.clause)
            args = append(args, j.args...)
        }
        fmt.Fprintf(buf, " FROM %s", joinBuf.String())
    }
    // --------------------- END NEW LINES -------------------

    where, whereArgs := whereClause(q, len(args)+1)
    //Code ommited...

    return buf, args
}

That works like this:

models.VehicleAlerts(BDL,
    qm.InnerJoin("device_data"),
    qm.Where("vehicle_id=?", 44),
    qm.And("device_data.transmission_reason=?", 55),
).UpdateAll(models.M{
    "device_datum_end_id": 66,
})

Results:

UPDATE "vehicle_alerts" SET "device_datum_end_id" = $1 FROM  device_data WHERE (vehicle_id=$2) AND (device_data.transmission_reason=$3);

What do you think, @aarondl?

Oh, it's for Postgres. It's different on MySQL...

[aarondl]

Well, for starters thanks for experimenting with the code! Secondly, we -do- have to stay true to our lowest common denominator so we'd have to look at if/how this works in both mysql, mssql and it's good to look at sqlite as well.

If it is indeed different on all of these db engines, then we don't have a lot of choices if we want the functionality. But putting db specific parts in this section of the code will probably be a net negative (for maintainability etc, every feature has a cost, especially when DB support is so varied).

I'd push back a little and ask: Do we -really- need this functionality, is it used as frequently as update itself is? I'd say that's fairly unlikely. Thoughts?

[aarondl]

Probably not going to implement this. Also stale.