Method getSampleBlock

src/Interpreters/InterpreterInsertQuery.cpp:201–230

}

Block InterpreterInsertQuery::getSampleBlock(
    const ASTInsertQuery & query,
    const StoragePtr & table,
    const StorageMetadataPtr & metadata_snapshot,
    ContextPtr context_,
    bool no_destination,
    bool allow_materialized)
{
    /// If the query does not include information about columns
    if (!query.columns)
    {
        if (auto * window_view = dynamic_cast<StorageWindowView *>(table.get()))
            return window_view->getInputHeader();
        if (no_destination)
            return metadata_snapshot->getSampleBlockWithVirtuals(VirtualsKind::All, VirtualsMaterializationPlace::All);
        return metadata_snapshot->getSampleBlockNonMaterialized();
    }

    /// Form the block based on the column names from the query
    const auto columns_ast = processColumnTransformers(context_->getCurrentDatabase(), table, metadata_snapshot, query.columns);
    Names names;
    names.reserve(columns_ast->children.size());
    for (const auto & identifier : columns_ast->children)
    {
        std::string current_name = identifier->getColumnName();
        names.emplace_back(std::move(current_name));
    }

    return getSampleBlock(names, table, metadata_snapshot, no_destination, allow_materialized);
}

Block InterpreterInsertQuery::getSampleBlock(
    const Names & names,