ref #9436
Currently EPHEMERAL column requires an explicit default value provided on CREATE TABLE - we can allow implicit default there

#include <Parsers/ASTColumnDeclaration.h>
#include <Common/quoteString.h>
#include <IO/Operators.h>
namespace DB
{
ASTPtr ASTColumnDeclaration::clone() const
{
    const auto res = std::make_shared<ASTColumnDeclaration>(*this);
    res->children.clear();
    if (type)
    {
        
        
        res->type = type->clone();
        res->children.push_back(res->type);
    }
    if (default_expression)
    {