|
|
Posted by --CELKO-- on 11/21/06 19:49
>> No, I didn't know that SQL has no boolean data type, and that BIT is proprietary, so thanks for that information. You can pretend it is an integer type if you prefer. Again, do not read anything into the table and field [sic] names .. <<
O)kay. You have SERIOUS conceptual problems with SQL and RDBMS. The
reason that SQL has no BOOLEAN data types is one of those "mathematical
foundations" things that has to do with NULLs, 3-valued logic and
logic. In 25 words or less, we discover a state of being via
predicates rather than by looking for a flag.
In procedural, step-by-step file system models you set flags in step
(n) to pass control information to step (n+1) of the process. In the RM
model, multiple users can change the basic facts of a schema and thus
the criteria of the subset, so we do not store computed columns. You
compute subset membership at run time.
Fields have mean because of the program that reads them; columns have a
domain, a value and constraints in the schema -- totally separate from
any program that uses them -- which give them meaning.
It does not matter if you use a Standard data type; you are still not
programming with relational data model. Think in terms of predicates,
sets and declarations, not flags, sequences and procedures.
Navigation:
[Reply to this message]
|