Modifications to support JDBC connections

cpp/server/brad_server_simple.cc

@@ -176,6 +176,10 @@ void BradFlightSqlServer::InitWrapper(
   auto location = arrow::flight::Location::ForGrpcTcp(host, port).ValueOrDie();
   arrow::flight::FlightServerOptions options(location);
 
+  // NOTE: We bypass authentication for simplicity -- this is not recommended in
+  // a production setting.
+  options.auth_handler = std::make_shared<arrow::flight::NoOpAuthHandler>();
+
   handle_query_ = handle_query;
 
   const auto status = this->Init(options);

src/brad/exec/cli.py

@@ -8,6 +8,7 @@
 import brad
 from brad.config.strings import SHELL_HISTORY_FILE
 from brad.grpc_client import BradGrpcClient, BradClientError
+from brad.flight_sql_client_odbc import BradFlightSqlClientOdbc
 
 
 def register_command(subparsers):
@@ -21,6 +22,9 @@ def register_command(subparsers):
         type=str,
         help="Run a single SQL query (or internal command) and exit.",
     )
+    parser.add_argument(
+        "--use-odbc", action="store_true", help="Use the ODBC endpoint instead of gRPC."
+    )
     parser.add_argument(
         "endpoint",
         nargs="?",
@@ -39,11 +43,15 @@ def parse_endpoint(endpoint: str) -> Tuple[str, int]:
 
 def run_command(args) -> None:
     host, port = parse_endpoint(args.endpoint)
-    with BradGrpcClient(host, port) as client:
-        run_query(client, args.command)
+    if args.use_odbc:
+        with BradFlightSqlClientOdbc(host, port) as client:
+            run_query(client, args.command)
+    else:
+        with BradGrpcClient(host, port) as client:
+            run_query(client, args.command)
 
 
-def run_query(client: BradGrpcClient, query: str) -> None:
+def run_query(client: BradGrpcClient | BradFlightSqlClientOdbc, query: str) -> None:
     try:
         # Dispatch query and print results. We buffer the whole result
         # set in memory to get a reasonable estimate of the query
@@ -79,7 +87,7 @@ class BradShell(cmd.Cmd):
     MULTILINE_PROMPT = "--> "
     TERM_STR = ";"
 
-    def __init__(self, client: BradGrpcClient) -> None:
+    def __init__(self, client: BradGrpcClient | BradFlightSqlClientOdbc) -> None:
         super().__init__()
         self.prompt = self.READY_PROMPT
         self._client = client
@@ -139,7 +147,7 @@ def main(args) -> None:
     print()
     print("Connecting to BRAD VDBE at {}:{}...".format(host, port))
 
-    with BradGrpcClient(host, port) as client:
+    def run_shell(client: BradGrpcClient | BradFlightSqlClientOdbc) -> None:
         print("Connected!")
         print()
         print("Terminate all SQL queries with a semicolon (;). Hit Ctrl-D to exit.")
@@ -148,3 +156,10 @@ def main(args) -> None:
 
         shell = BradShell(client)
         shell.cmdloop()
+
+    if args.use_odbc:
+        with BradFlightSqlClientOdbc(host, port) as client:
+            run_shell(client)
+    else:
+        with BradGrpcClient(host, port) as client:
+            run_shell(client)

src/brad/flight_sql_client_odbc.py

@@ -1,5 +1,6 @@
 import pyodbc
 from typing import Generator, Optional, Self, Tuple, List, Any
+from brad.config.engine import Engine
 
 
 class BradFlightSqlClientOdbc:
@@ -52,3 +53,16 @@ def run_query_generator(self, query: str) -> Generator[Tuple[Any, ...], None, No
     def run_query(self, query: str) -> RowList:
         assert self._cursor
         return self._cursor.execute(query)
+
+    def run_query_json_cli(self, query: str) -> Tuple[RowList, Optional[Engine], bool]:
+        self.run_query(query)
+        assert self._cursor
+        results = self._cursor.fetchall()
+        all_rows = [tuple(row) for row in results]
+        return all_rows, None, False
+
+    def run_prepared(self, query: str, params: Tuple[Any, ...]) -> RowList:
+        assert self._cursor
+        self._cursor.execute(query, params)
+        results = self._cursor.fetchall()
+        return [tuple(row) for row in results]

tools/flight_sql_jdbc/JdbcConnectionExample.java

@@ -0,0 +1,64 @@
+import java.sql.*;
+
+// This example is used to test JDBC connections to BRAD VDBEs (using the Arrow
+// Flight SQL JDBC driver).
+public class JdbcConnectionExample {
+    public static void main(String[] args) throws SQLException {
+        try {
+            Class.forName("org.apache.arrow.driver.jdbc.ArrowFlightJdbcDriver"); // Example driver class
+        } catch (ClassNotFoundException e) {
+            System.err.println("Driver not found: " + e.getMessage());
+            return; // Exit if driver not found
+        }
+
+        String url = "jdbc:arrow-flight-sql://<host>:<port>/?useEncryption=false"; // Example URL
+        String user = "your_username";
+        String password = "your_password";
+
+        try (Connection connection = DriverManager.getConnection(url, user, password)) {
+            System.out.println("Connected to the database!");
+
+            // Regular statement.
+            try (Statement statement = connection.createStatement()) {
+                String sql = "SELECT 1, 2, 3 FROM homes LIMIT 5";
+
+                // 5. Execute the query
+                try (ResultSet resultSet = statement.executeQuery(sql)) {
+
+                    // 6. Process the results
+                    while (resultSet.next()) {
+                        // Access columns by name or index
+                        int val1 = resultSet.getInt(1);
+                        int val2 = resultSet.getInt(2);
+                        int val3 = resultSet.getInt(3);
+                        System.out.println("val1: " + val1 + ", val2: " + val2 + ", val3: " + val3);
+                    }
+                }
+            }
+
+            // Prepared statement.
+            String sql = "SELECT id, name FROM your_table WHERE status = ?"; // Example query
+            try (PreparedStatement statement = connection.prepareStatement(sql)) {
+
+                // 4. Set parameters for the PreparedStatement
+                String status = "active"; // Example parameter value
+                statement.setString(1, status); // Set the first parameter (index 1)
+
+                // 5. Execute the query
+                try (ResultSet resultSet = statement.executeQuery()) {
+
+                    // 6. Process the results (if any)
+                    while (resultSet.next()) {
+                        int id = resultSet.getInt("id");
+                        String name = resultSet.getString("name");
+                        System.out.println("ID: " + id + ", Name: " + name);
+                    }
+                }
+            }
+
+        } catch (SQLException e) {
+            System.err.println("Database error: " + e.getMessage());
+        }
+
+    }
+}