queue

queue :: (
    p: *Pipeline,
    $sql: string,
    args: ..Any,
    $call := #caller_code
) -> (Pending(Rows(#run row_type(sql, call, 1, #insert,scope(call) #run row_table_type(sql, call, 1, #insert,scope(call) #run row_table_exists(sql, call, 1)), Row(#run row_shape(sql, call, 1))))), Pg_Error)

query on a pipeline: the statement is queued, checked like query, and its rows come later from take. Queue several, then take them: they share one round trip.

Not run: it needs a PostgreSQL server.

Parameters

p: *Pipeline

the pipeline to queue on.

$sql: string

the statement, as for query.

args: ..Any

one value per %, in order.

$call := #caller_code

the code of the call, which lets the query text be checked while compiling. Leave the default.

Returns

Pending(Rows(#run row_type(sql, call, 1, #insert,scope(call) #run row_table_type(sql, call, 1, #insert,scope(call) #run row_table_exists(sql, call, 1)), Row(#run row_shape(sql, call, 1)))))

Pg_Error

p := Pg.pipeline_enter(c);
users := Pg.queue(p, "select id, name from users where id = $1", id);
count := Pg.queue_execute(p, "update users set seen = now() where id = $1", id);
rows, error := Pg.take(p, users);
changed, error = Pg.take(p, count);
Pg.pipeline_exit(p);