Plsql Tutorial
primary key is a single field or combination of fields that uniquely defines a record. None of the fields that are part of the primary key can contain a null value. A table can have only one primary key
Oracle PL/SQL: Oracle System Tables. Below is an alphabetical listing of the Oracle system tables that are commonly used.
A cursor is a mechanism by which you can assign a name to a “select statement” and manipulate the information within that SQL statement. This tutorial is a continuity of Oracle PL/SQL Cursors which discuses some basic functionalities of PL/SQL Cursors.
A cursor is a mechanism by which you can assign a name to a “select statement” and manipulate the information within that SQL statement.
Oracle PL/SQL: Commit Transactions
The syntax for the COMMIT statement is:
COMMIT [WORK] [COMMENT text];
The Commit statement commits all changes for the current session. Once a commit is issued, other users will be able to see your changes.
Oracle PL/SQL: Rollback Transactions
The syntax for the ROLLBACK statement is:
ROLLBACK [WORK] [TO [SAVEPOINT] savepoint_name];
The Rollback statement undoes all [...]
In Oracle, you can create an autonumber field by using sequences. A sequence is an object in Oracle that is used to generate a number sequence. This can be useful when you need to create a unique number to act as a primary key
Continue reading about Oracle PL/SQL: Sequences (Autonumber)
This article contains tutorial about Oracle PL/SQL Loops and Conditional Statements. Following topics are discused here IF-THEN-ELSE Statement, Case Statement, GOTO Statement, Loop Statement, FOR Loop, CURSOR FOR Loop, While Loop, Repeat Until Loop and Exit Statement
Continue reading about Oracle PL/SQL: Loops and Conditional Statements
In other languages, a null value is found using the = null syntax. However in PLSQL to check if a value is null, you must use the "IS NULL" syntax.
To check for equality on a null value, you must use "IS NULL".
For example,
IF Lvalue IS NULL then
.
END IF;
If Lvalue contains a null value, [...]
The syntax for declaring variables is:
variable_name datatype [CONSTANT] [NOT NULL] [:= | DEFAULT initial_value]
For example:
Declaring a variable:
LDescription varchar2(40);
Declaring a constant:
LTotal constant numeric(8,1) := 8363934.1;
Declaring a variable with an initial value (not a constant):
LType varchar2(10) := ‘Example’;
A literal is the same as a constant. We’ll cover three types of literals – text literals, integer literals, and number literals
