Function validateVirtualColumns

src/Interpreters/InterpreterCreateQuery.cpp:1884–1908

}

void validateVirtualColumns(IStorage & storage, ContextPtr context)
{
    const auto metadata = storage.getInMemoryMetadataPtr(context, false);
    for (const auto & storage_column : metadata->columns)
    {
        if (metadata->virtuals.tryGet(storage_column.name, VirtualsKind::Persistent, VirtualsMaterializationPlace::All))
        {
            throw Exception(ErrorCodes::ILLEGAL_COLUMN,
                "Cannot create table with column '{}' for {} engines because it is reserved for persistent virtual column",
                storage_column.name, storage.getName());
        }

        /// An EPHEMERAL user column has no physical storage and no read-time expression,
        /// so it cannot properly shadow a virtual column of the same name.
        /// This leads to a type mismatch: the Block header uses the user column's type
        /// while the data comes from the virtual column (which may have a different type).
        if (storage_column.default_desc.kind == ColumnDefaultKind::Ephemeral && metadata->virtuals.tryGet(storage_column.name, VirtualsKind::Ephemeral, VirtualsMaterializationPlace::All))
        {
            throw Exception(ErrorCodes::ILLEGAL_COLUMN,
                "Cannot create table with ephemeral column '{}' for {} engines "
                "because it conflicts with a virtual column of the same name",
                storage_column.name, storage.getName());
        }
    }
}

void validateStorage(IStorage & storage, LoadingStrictnessLevel mode, ContextPtr context)
try