Method analyzeMultiQueryText

src/Client/ClientBase.cpp:2685–2815

MultiQueryProcessingStage ClientBase::analyzeMultiQueryText(
    const char *& this_query_begin, const char *& this_query_end, const char * all_queries_end,
    ASTPtr & parsed_query,
    std::unique_ptr<Exception> & current_exception)
{
    if (!is_interactive && cancelled)
        return MultiQueryProcessingStage::QUERIES_END;

    if (this_query_begin >= all_queries_end)
        return MultiQueryProcessingStage::QUERIES_END;

    // Remove leading empty newlines and other whitespace, because they
    // are annoying to filter in the query log. This is mostly relevant for
    // the tests.
    while (this_query_begin < all_queries_end && isWhitespaceASCII(*this_query_begin))
        ++this_query_begin;

    if (this_query_begin >= all_queries_end)
        return MultiQueryProcessingStage::QUERIES_END;

    unsigned max_parser_depth = static_cast<unsigned>(client_context->getSettingsRef()[Setting::max_parser_depth]);
    unsigned max_parser_backtracks = static_cast<unsigned>(client_context->getSettingsRef()[Setting::max_parser_backtracks]);

    // If there are only comments left until the end of file, we just
    // stop. The parser can't handle this situation because it always
    // expects that there is some query that it can parse.
    // We can get into this situation because the parser also doesn't
    // skip the trailing comments after parsing a query. This is because
    // they may as well be the leading comments for the next query,
    // and it makes more sense to treat them as such.
    {
        Tokens tokens(this_query_begin, all_queries_end);
        IParser::Pos token_iterator(tokens, max_parser_depth, max_parser_backtracks);
        if (!token_iterator.isValid())
            return MultiQueryProcessingStage::QUERIES_END;
    }

    this_query_end = this_query_begin;
    try
    {
        parsed_query = parseQuery(this_query_end, all_queries_end,
            client_context->getSettingsRef(),
            /*allow_multi_statements=*/ true);
    }
    catch (const Exception & e)
    {
        current_exception.reset(e.clone());
        return MultiQueryProcessingStage::PARSING_EXCEPTION;
    }

    if (!parsed_query)
    {
        if (ignore_error)
        {
            Tokens tokens(this_query_begin, all_queries_end);
            IParser::Pos token_iterator(tokens, max_parser_depth, max_parser_backtracks);
            while (token_iterator->type != TokenType::Semicolon && token_iterator.isValid())
                ++token_iterator;