Function extractPrimaryKeyColumnNames

programs/copier/Internals.cpp:213–258

Names extractPrimaryKeyColumnNames(const ASTPtr & storage_ast)
{
    const auto sorting_key_ast = extractOrderBy(storage_ast);
    const auto primary_key_ast = extractPrimaryKey(storage_ast);

    const auto sorting_key_expr_list = extractKeyExpressionList(sorting_key_ast);
    const auto primary_key_expr_list = primary_key_ast
                           ? extractKeyExpressionList(primary_key_ast) : sorting_key_expr_list->clone();

    /// Maybe we have to handle VersionedCollapsing engine separately. But in our case in looks pointless.

    size_t primary_key_size = primary_key_expr_list->children.size();
    size_t sorting_key_size = sorting_key_expr_list->children.size();

    if (primary_key_size > sorting_key_size)
        throw Exception("Primary key must be a prefix of the sorting key, but its length: "
                        + toString(primary_key_size) + " is greater than the sorting key length: " + toString(sorting_key_size),
                        ErrorCodes::BAD_ARGUMENTS);

    Names primary_key_columns;
    NameSet primary_key_columns_set;

    for (size_t i = 0; i < sorting_key_size; ++i)
    {
        /// Column name could be represented as a f_1(f_2(...f_n(column_name))).
        /// Each f_i could take one or more parameters.
        /// We will wrap identifiers with backticks to allow non-standart identifier names.
        String sorting_key_column = sorting_key_expr_list->children[i]->getColumnName();

        if (i < primary_key_size)
        {
            String pk_column = primary_key_expr_list->children[i]->getColumnName();
            if (pk_column != sorting_key_column)
                throw Exception("Primary key must be a prefix of the sorting key, but the column in the position "
                                + toString(i) + " is " + sorting_key_column +", not " + pk_column,
                                ErrorCodes::BAD_ARGUMENTS);

            if (!primary_key_columns_set.emplace(pk_column).second)
                throw Exception("Primary key contains duplicate columns", ErrorCodes::BAD_ARGUMENTS);

            primary_key_columns.push_back(wrapIdentifiersWithBackticks(primary_key_expr_list->children[i]));
        }
    }

    return primary_key_columns;
}

bool isReplicatedTableEngine(const ASTPtr & storage_ast)
{