[BUG] Driver throws exception when query starts with multi-line block comment

[rileythomp]

Describe the bug

When you try to execute a query that has a multi-line block comment above the query itself an exception is thrown.

To Reproduce

clj \
 -J--add-opens=java.base/java.nio=org.apache.arrow.memory.core,ALL-UNNAMED \
 -Sdeps '{:deps {com.databricks/databricks-jdbc-thin {:mvn/version "3.1.1"}}}'

(do
  (import '[java.sql DriverManager])

  (with-open [conn (DriverManager/getConnection "<databricks-jdbc-url>")
              stmt (.createStatement conn)
              rs (.executeQuery stmt "/*
                                      multi line block comment
                                      */
                                      select 1;")]
    (when (.next rs)
      (.getInt rs 1))))

Execution error (DatabricksSQLException) at com.databricks.jdbc.api.impl.DatabricksStatement/executeQuery (DatabricksStatement.java:82).
A ResultSet was expected but not generated from query. However, query execution was successful.

Expected behavior

The query results are returned correctly:

1

Client side logs
n/a

Client Environment (please complete the following information):

• OS: Mac
• Java version: 23.0.2
• Java vendor: OpenJDK
• Driver Version: 3.1.1
• BI Tool: Metabase
• BI Tool version: 58.4

Additional context

I think it might be an issue with the regex comment parsing in trimCommentsAndWhitespaces

[rileythomp]

Also errors with nested block comments, Java repro:

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Main {
    public static void main(String[] args) throws Exception {
        String url = "<databricks-jdbc-url>";
        Connection conn = DriverManager.getConnection(url);
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("""
        /* /* nested block comment */ */
        SELECT 9
        """);
        while (rs.next()) {
            System.out.println("Result: " + rs.getInt(1));
        }
    }
}

[rileythomp]

@samikshya-db If no one else is working on this can I open a PR to add proper comment handling? It would also fix DatabricksParameterMetaData.countParameters which has a bug with ? in nested block comments

[jayantsing-db]

hey @rileythomp please feel free to open the PR

[samikshya-db]

Hello @rileythomp - feel free to open a contribution, thank you!

[rileythomp]

@samikshya-db @jayantsing-db Okay thanks I've opened #1207 for review

[samikshya-db]

Thanks for the contribution once again, @rileythomp

The change will be part of the next release. Closing the issue.