tmp.proto

syntax = "proto3";

import "google/protobuf/any.proto";

package server;

service SQLFlow {
  rpc Query (Request) returns (stream RowSet);
  rpc Execute (Request) returns (stream Messages);
}

// SQL statements to run
// e.g.
//      1. `SELECT ...`
//      2. `USE ...`, `DELETE ...`
//      3. `SELECT ... TRAIN/PREDICT ...`
message Request {
  string sql = 1;		// The SQL statement to be executed.
}

// SQL statements like `SELECT ...`, `DESCRIBE ...` returns a rowset.
// The rowset might be big. In such cases, Query returns a stream
// of RunResponse
message RowSet {
  repeated string column_names = 1;
  repeated Row rows = 2;

  // A row of data. Data can be any type
  message Row {
    repeated google.protobuf.Any data = 1;
  }
}

// SQL statements like `USE database`, `DELETE` returns only a success
// message.
//
// SQL statement like `SELECT ... TRAIN/PREDICT ...` returns a stream of
// messages which indicates the training/predicting progress
message Messages {
  repeated string messages = 1;
}