Example of coalesce operator - sql, PL-SQL Programming

Assignment Help:

Example of COALESCE operator

Example: Give the total of marks for each exam (simplified solution)

SELECT CourseId,

COALESCE ((SELECT SUM (Mark)

FROM EXAM_MARK AS EM

WHERE EM.CourseId = C.CourseId ),

0) AS TotalMark

FROM COURSE AS C

Explanation

The first operand to the invocation of COALESCE is a scalar subquery similar to Aggregate Operators. Recall the need to enclose the SELECT expression in parentheses, without which it would denote a table rather than a number.

Related Discussions:- Example of coalesce operator - sql

Sql pseudocolumns, SQL Pseudocolumns The PL/SQL recognizes the followin...

SQL Pseudocolumns The PL/SQL recognizes the following SQL pseudocolumns, that returns the specific data items: LEVEL, NEXTVAL, CURRVAL, ROWID, & ROWNUM. The Pseudocolumns are n

Pass the nulls to a dynamic sql, Pass the nulls to a dynamic SQL: Pas...

Pass the nulls to a dynamic SQL: Passing Nulls: Assume that you want to pass the nulls to a dynamic SQL statement. For illustration, you may write the EXECUTE IMMEDIATE

Oracle, Literature review

Literature review

Assignment2, How do I display usernames for students from a student table, ...

How do I display usernames for students from a student table, assigning each student a username initials001 (initials is the actual student initials), and if the students initials

Constants and variables in pl sql, Constants and Variables: You can...

Constants and Variables: You can declare the constants and variables in the declarative section of any PL/SQL subprogram, block, or package. The Declarations allot the stor

Relational shema.., Find the account numbers of all customers whose balance...

Find the account numbers of all customers whose balance is more than 10,000 $

Anatomy of a table, Anatomy of a Table: Figure shows the terminology u...

Anatomy of a Table: Figure shows the terminology used in SQL to refer to parts of the structure of a table. As you can see, SQL has no official terms for its counterpa

Benefit of the dynamic sql pl sql, Benefit of the dynamic SQL: This pa...

Benefit of the dynamic SQL: This part shows you how to take full benefit of the dynamic SQL and how to keep away from some of the common pitfalls. Passing the Names of Sc

Using exception_init - user-defined exceptions, Using EXCEPTION_INIT T...

Using EXCEPTION_INIT To handle unnamed internal exceptions, you should use the OTHERS handler or the pragma EXCEPTION_INIT. The pragma is a compiler directive that can be th

Prepare a slq project, Project Description: I want to write some SQL st...

Project Description: I want to write some SQL statements. The things I need are between pages 5-7. The only problem is that i want it till tomorrow. Skills required is SQL

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages