oznfc•8mo ago

Dynamic funtion in convex

how can ı write this codes's convex funtion ?

query = "SELECT * FROM flights WHERE 1 = 1"
    params = []

    if departure_airport:
        query += " AND departure_airport = ?"
        params.append(departure_airport)

    if arrival_airport:
        query += " AND arrival_airport = ?"
        params.append(arrival_airport)

    if start_time:
        query += " AND scheduled_departure >= ?"
        params.append(start_time)

    if end_time:
        query += " AND scheduled_departure <= ?"
        params.append(end_time)

4 Replies

lee•8mo ago

When running this hypothetical sql query, what index(es) are on the flights table?

lee•8mo ago

If there are no indexes, the equivalent Convex code would use filter https://stack.convex.dev/complex-filters-in-convex

const query = filter(ctx.db.query("flights"), (flight) => {
  if (departure_airport && departure_airport !== flight.departure_airport) return false;
  if (arrival_airport && arrival_airport !== flight.arrival_airport) return false;
  if (start_time && start_time > flight.scheduled_departure) return false;
  ... etc ...
  return true;
});

const query = filter(ctx.db.query("flights"), (flight) => {
  if (departure_airport && departure_airport !== flight.departure_airport) return false;
  if (arrival_airport && arrival_airport !== flight.arrival_airport) return false;
  if (start_time && start_time > flight.scheduled_departure) return false;
  ... etc ...
  return true;
});

Stack

Using TypeScript to Write Complex Query Filters

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oznfcOP•8mo ago

when ı tried without indexes getting limit error so ı added index but no idea for with indexes:


  flights: defineTable({
    actual_arrival: v.union(v.null(), v.string()),
    actual_departure: v.union(v.null(), v.string()),
    aircraft_code: v.string(),
    arrival_airport: v.string(),
    departure_airport: v.string(),
    flight_id: v.float64(),
    flight_no: v.string(),
    scheduled_arrival: v.string(),
    scheduled_departure: v.string(),
    status: v.string(),
  }).index("by_departure_airport", ["departure_airport"])
    .index("by_arrival_airport", ["arrival_airport"])
    .index("by_actual_departure", ["actual_departure"])
    .index("by_actual_arrival", ["actual_arrival"]),
})

lee•8mo ago

You should pick an index that narrows down your search space as much as possible. See https://stack.convex.dev/databases-are-spreadsheets to think about how to design your indexes and pick one

Stack

Databases are Spreadsheets

I want to share my mental model of databases: - Databases are just big spreadsheets - An index is just a view of the spreadsheet sorted by one or mor...

Dynamic funtion in convex

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