Function sanitizeSQLAlias

src/optimizer/foreign_join_push_down_optimizer.cpp:340–350

};

static std::string sanitizeSQLAlias(std::string alias) {
    for (auto& ch : alias) {
        if (!std::isalnum(static_cast<unsigned char>(ch)) && ch != '_') {
            ch = '_';
        }
    }
    if (alias.empty() || std::isdigit(static_cast<unsigned char>(alias[0]))) {
        alias = "col_" + alias;
    }
    return alias;
}

// Build the SQL join query string and collect column names for result mapping.
// Keep result column names SQL-safe while using display names that preserve the user's labels.