01-30-2011
ok so a primary key in table A is a foreign key in table B (not a primary)
so table A table B
uid - primary key ser_id - Primary key
name uid - foreign key
password trans_id
then
select A.*, B.trans_id
from A,B
where A.uid = B.uid
so a 3rd normal form of relational DB.
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LEARN ABOUT MOJAVE
drop_table
DROP
TABLE(7) SQL Commands DROP TABLE(7)
NAME
DROP TABLE - remove a table
SYNOPSIS
DROP TABLE [ IF EXISTS ] name [, ...] [ CASCADE | RESTRICT ]
DESCRIPTION
DROP TABLE removes tables from the database. Only its owner can drop a table. To empty a table of rows without destroying the table, use
DELETE [delete(7)] or TRUNCATE [truncate(7)].
DROP TABLE always removes any indexes, rules, triggers, and constraints that exist for the target table. However, to drop a table that is
referenced by a view or a foreign-key constraint of another table, CASCADE must be specified. (CASCADE will remove a dependent view
entirely, but in the foreign-key case it will only remove the foreign-key constraint, not the other table entirely.)
PARAMETERS
IF EXISTS
Do not throw an error if the table does not exist. A notice is issued in this case.
name The name (optionally schema-qualified) of the table to drop.
CASCADE
Automatically drop objects that depend on the table (such as views).
RESTRICT
Refuse to drop the table if any objects depend on it. This is the default.
EXAMPLES
To destroy two tables, films and distributors:
DROP TABLE films, distributors;
COMPATIBILITY
This command conforms to the SQL standard, except that the standard only allows one table to be dropped per command, and apart from the IF
EXISTS option, which is a PostgreSQL extension.
SEE ALSO
ALTER TABLE [alter_table(7)], CREATE TABLE [create_table(7)]
SQL - Language Statements 2010-05-14 DROP TABLE(7)