Archive for April 2015
Types of Views
Simple View
Complex View
Materialized View
Force View
Simple View ...
- Simple View is the view that is created based on a single table
- Derives data...
What is View?
A view is a named and validated SQL query which is stored in the Oracle data dictionary.
View does not have storage of its own (i.e. View does not hold any data) .
It is just a stored...
NEXTVAL and CURRVAL Pseudo columns
NEXTVAL returns the next available sequence value.
It returns a unique value every time it is referenced, even for different users.
CURRVAL obtains...
What are Synonyms?
Synonyms are aliases for tables, views, sequences.
Simplify access to objects by creating a synonym (another name for an object).
Shorten lengthy object names.
Creating a Synonym...
What is Sequence?
Sequences are used to generate unique, sequential integer values that are used as primary key values in database tables.
Speeds up the efficiency of accessing sequence values when...
What is Index?
Allows users to quickly locate specific records.
It is a performance-tuning method that is used to speed up retrieval of records by using a pointer.
An index creates an entry for...
Select list item in oracle apex always have two values that is display value and return value.
Syntax :
SELECT Display_Value,Return_Value FROM Table_Name;
E.g.:
SELECT EXPENSE_START_DATE,PERIOD_ID FROM U_EXPENSE_PERIODS;
...
SQL is Structured Query Language, which is a computer language for storing, manipulating and retrieving data stored in relational database.
SQL is the standard language...
