googleapis/mcp-toolbox · error

unable to execute query: %w

Error message

unable to execute query: %w

What it means

RunSQL executes the statement through the pool's QueryContext. Any error returned by the driver during query execution is wrapped as 'unable to execute query', preserving the original via %w.

Source

Thrown at internal/sources/clickhouse/clickhouse.go:115

	return SourceType
}

func (s *Source) ToConfig() sources.SourceConfig {
	return s.Config
}

func (s *Source) ClickHousePool() *sql.DB {
	return s.Pool
}

func (s *Source) RunSQL(ctx context.Context, statement string, params parameters.ParamValues) (any, error) {
	var sliceParams []any
	if params != nil {
		sliceParams = params.AsSlice()
	}
	results, err := s.ClickHousePool().QueryContext(ctx, statement, sliceParams...)
	if err != nil {
		return nil, fmt.Errorf("unable to execute query: %w", err)
	}
	defer results.Close()

	cols, err := results.Columns()
	if err != nil {
		return nil, fmt.Errorf("unable to retrieve rows column name: %w", err)
	}

	// create an array of values for each column, which can be re-used to scan each row
	rawValues := make([]any, len(cols))
	values := make([]any, len(cols))
	for i := range rawValues {
		values[i] = &rawValues[i]
	}

	colTypes, err := results.ColumnTypes()
	if err != nil {
		return nil, fmt.Errorf("unable to get column types: %w", err)

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Unwrap the error to see ClickHouse's server-side message.
2. Test the statement directly in clickhouse-client.
3. Verify table/column names and permissions for the configured user.
4. Check the connection is still alive (server may have closed it).

Example fix

// before
"SELECT * FORM my_table"
// after
"SELECT * FROM my_table"

rows, err := src.RunSQL(ctx, stmt)
if err != nil {
    if strings.Contains(err.Error(), "unable to execute query") {
        return fmt.Errorf("sql rejected: %w", err)
    }
    return err
}

When it happens

Trigger: Calling RunSQL with an invalid SQL statement, syntax error, missing table/column, insufficient permissions, or a connection dropped mid-query.

Common situations: Typos in SQL, referencing non-existent tables, ClickHouse rejecting the query syntax, auth failures, query size/limits exceeded.

Related errors

• unable to retrieve rows column name: %w
• unable to get column types: %w
• unable to parse rows: %w
• unable to create pool: %w
• unable to connect successfully: %w

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/2640745e02680dd1. Report an issue: GitHub.