If cnc is not null, then checks that all the database objects referenced in the statement actually
exist in the connection's database (for example the table being updated in a UPDATE statement must exist in the
connection's database for the check to succeed). This method fills the stmt->validity_meta_struct attribute.
If cnc is null, then remove any information from a previous call to this method stored in stmt. In this case,
the stmt->validity_meta_struct attribute is cleared.
Also note that some parts of stmt may be modified: for example leading and trailing spaces in aliases or
objects names will be removed.
If cnc is not null, then checks that all the database objects referenced in the statement actually exist in the connection's database (for example the table being updated in a UPDATE statement must exist in the connection's database for the check to succeed). This method fills the stmt->validity_meta_struct attribute.
If cnc is null, then remove any information from a previous call to this method stored in stmt. In this case, the stmt->validity_meta_struct attribute is cleared.
Also note that some parts of stmt may be modified: for example leading and trailing spaces in aliases or objects names will be removed.