Renaming columns - sql, PL-SQL Programming

Assignment Help:

Renaming Columns - SQL

SQL has no direct counterpart of RENAME. To derive the table on the right in Figure 4.4 from the table on the left, Tutorial D has IS_CALLED RENAME ( StudentId AS Sid ).

1010_Renaming Columns - SQL.png

                                                    Figure: Tables differing only in a column name

It shows how the same effect can be achieved in SQL. Note that the SELECT clause has to include all the columns that are not subject to renaming, as well as those that are.

Example: Renaming a column

SELECT StudentId AS Sid, Name

FROM IS_CALLED

Explanation

  • Each element of a SELECT clause is an expression of arbitrary complexity that can reference one or more columns of the SELECT clause's input table. Note that the expression is not required to reference any columns: it might be just a literal, for example.
  • If the expression consists of just a column reference, then the name of the referenced column is the name of the corresponding column in the result.
  • If the expression is followed by the key word AS, then the resulting column has the column name given after that key word.

SQL allows the result to have two or more columns of the same name. For example, if we replace Sid by Name in Example, we still have a valid SQL SELECT expression.


Related Discussions:- Renaming columns - sql

Need fullcalendar modifications, Project Description: I am looking to ch...

Project Description: I am looking to change FullCalendar to add/delete sql server data when events are removed or dropped from Calendar. Events should only be included by dra

Exceptions are raised - Using Raise statement, How Exceptions Are Raised ...

How Exceptions Are Raised By the run-time system, the internal exceptions are raised implicitly as are user-defined exceptions that you have related with an Oracle error number

Testing triggers, Demonstrate your knowledge of PL/SQL programming by writi...

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

Name resolution - pl/sql, Name Resolution   During the compilation, th...

Name Resolution   During the compilation, the PL/SQL compiler relates identifiers like the name of a variable with an address or memory location, actual value, or datatype. Th

Keyword, what is the use of declare keyword

what is the use of declare keyword

Primary key, PRIMARY KEY: PRIMARY KEY  indicates that the table is sub...

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

Using host arrays - bulk bind performance improvement, Using Host Arrays ...

Using Host Arrays The Client-side programs can use anonymous PL/SQL blocks to bulk-bind input and output host arrays. However, this is the well-organized way to pass the colle

Wrapping and unwrapping in sql, Wrapping and unwrapping in SQL Operato...

Wrapping and unwrapping in SQL Operators WRAP and UNWRAP in connection with attributes whose declared types are tuple types. Example shows how extension and projection can be

Example of table literal - sql, Example of Table Literal - SQL Exampl...

Example of Table Literal - SQL Example: A Table Literal (correct version) VALUES ('S1', 'C1', 'Anne'), ('S1', 'C2', 'Anne'), ('S2', 'C1', 'Boris'), ('S3', 'C3'

Creating Views, Create a view named CustomerAddresses that shows the shippi...

Create a view named CustomerAddresses that shows the shipping and billing addresses for each customer in the MyGuitarShop database. This view should return these columns from the

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd