Primary key, PL-SQL Programming

PRIMARY KEY:

PRIMARY KEY  indicates that the table is subject to a key constraint, in this case declaring that no two rows in the table assigned to ENROLMENT can ever have the same combination of StudentId and CourseId fields (i.e., we cannot enrol the same student on the same course more than once, so to speak). We will learn more about SQL constraints in general and SQL's key constraints.

Posted Date: 1/11/2013 5:22:39 AM | Location : United States







Related Discussions:- Primary key, Assignment Help, Ask Question on Primary key, Get Answer, Expert's Help, Primary key Discussions

Write discussion on Primary key
Your posts are moderated
Related Questions
OPEN-FOR Statement The OPEN-FOR statements execute the multi-row query related with a cursor variable. It also allocates the resources used by the Oracle to process the query a

Raise_application_error -  procedure of package DBMS_STANDARD , allows to issue an user_defined error messages by stored sub-program or database trigger.

Organi c Evolution Evolution is a slow continuous, irreversible and natural process of change to give rise to advance and diverse forms of life i.e. formation of new specie

Tables within a Table - SQL Figure here is an exact copy of the one in the theory book and as before it is just an alternative way of representing some of the information con

Obtaining a natural join by specifying the common columns Synatax: SELECT * FROM IS_CALLED JOIN IS_ENROLLED_ON USING ( StudentId ) However, a named columns join doe

Package STANDARD The package named STANDARD defines the PL/SQL atmosphere. The package specification globally declares the exceptions, types, and subprograms that are available

Package Body: The package specification is implemented by the package body. That is, the package body has the definition of every cursor and the subprogram declared in the pac

Description: Demonstrate your knowledge of PL/SQL programming by writing and thoroughly testing triggers and stored procedures associated with an e-commerce application that pr

Need Windows and Linux system Administrator We are seeking a part time system administrator to take care of our servers. Your things to do would add, but not limited to: -

Functions The function is a subprogram which can take parameters and be invoked. Normally, you can use a function to calculate a value. The function has 2 sections: the specifi