Introduction to declaring PL/SQL Variables in Oracle
This course starts off by introducing you to PL/SQL and the tools that you can use to build your queries with PL/SQL.
Then you will learn about the different variable types that are used within PL/SQL.
You will also enhance your knowledge of non-PL/SQL bind and host variables.
You will also learn about the
package procedure: to display the output to your screen.
Finally, you will review some of the recommended naming conventions for application code.
select COUNT(*) into :BookCount from BOOKSHELF;
:= (Set Equal To)
variable := expression
DESCRIPTION: The PL/SQL variable is set equal to the expression, which may be a constant, NULL, or a calculation with other variables, literals, and PL/SQL functions.
Extension := Quantity * Price;
Title := 'BARBERS WHO SHAVE THEMSELVES';
Name := NULL;
By the end of this module, you will know how to:
- Define the term PL/SQL and describe some of the common tools used to develop PL/SQL
- Identify different types of variables
- Identify variable datatypes
- Use the non-PL/SQL bind and host variables to manipulate data within SQL*Plus
- Use the
DBMS_OUTPUT.PUT_LINE package procedure to display values to the SQL*Plus screen
- Illustrate the importance of naming conventions for application code
In the next lesson, we will begin by defining what PL/SQL is.
Variables are memory regions used in a PL/SQL block to hold data. They are
defined in the DECLARATION section of the block, where they are assigned a
specific data type and are often initialized with a value. The syntax for declaring
a variable is
variable_name [CONSTANT] type [NOT NULL] [:= value];
Variable_name is the name you give to the variable. Type is the data type the variable
needs to support. Value is used to initialize a variable.
The following example shows some different ways to declare variables:
v_author_count PLS_INTEGER := 0;
v_date DATE NOT NULL DEFAULT SYSDATE;
The greater the number of entangled particles, the greater the probablity that the entire system as a whole will collapse at any moment.