in general, user should save output of `DESC foo.bar` to a file,
and pass the path to the file as the argument of `--schema-file`
option of `scylla sstable` commands. the CQL statement generated
from `DESC` command always include the keyspace name of the table.
but in case user create the CQL statement manually and misses
the keyspace name. he/she would have following assertion failure
```
scylla: cql3/statements/cf_statement.cc:49: virtual const sstring &cql3::statements::raw::cf_statement::keyspace() const: Assertion `_cf_name->has_keyspace()' failed.
```
this is not a great user experience.
so, in this change, we check for the existence of keyspace before
looking it up. and throw a runtime error with a better error mesage.
so when the CQL statement does not have the keyspace name, the new
error message would look like:
```
error processing arguments: could not load schema via schema-file: std::runtime_error (tools::do_load_schemas(): CQL statement does not have keyspace specified)
```
since this check is only performed by `do_load_schemas()` which
care about the existence of keyspace, and it only expects the
CQL statement to create table/keyspace/type, we just override the
new `has_keyspace()` method of the corresponding types derived
from `cf_statement`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#16981
f96d25a0a7