Category: Oracle database tutorial
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Data dictionary views in Oracle
1. Introduction The data dictionary refers to the core collection of read-only reference tables and views within every Oracle database. The dynamic performance views are special views that are continuously updated while a database is open and in use. Since Oracle Database stores the data dictionary information in tables, similar to other data, users can…
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Direct Access to Objects in Another Schema
1. Introduction When accessing objects like tables, views, or procedures in another schema in Oracle, there are certain rules to follow, even if you have the required privileges to interact with the object. By default, if you want to access an object (for example, a table) in a different schema, you cannot simply reference it…
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Introduction to database objects
1. Introduction Database objects are the fundamental components of a database that are used to store, organize, and manage data. Understanding these objects is crucial for designing, implementing, and interacting with a database. Oracle database has many database objects categorized as Schema objects and non-schema objects. 2. Schema objects In Oracle Database, a schema is…
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PL/SQL %ROWTYPE Attribute
1. Introduction The %ROWTYPE attribute enables you declare a record that represents either a partial or full row of a database table or view. For every column of the full or partial row, the record has a field with the same data type and name. If the structure of the row changes, then the structure…
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PL/SQL %TYPE Attribute
1. Introduction The %TYPE attribute lets you declare a data item of the same data type as a previously declared variable or column. It is not necessary to know the type of the variable while using %TYPE attribute.For example, if you want to declare a variable in a PL/SQL block, which is of the same…
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PL/SQL – Basic Syntax
1. Introduction In this tutorial, we’ll discuss basic syntax of PL/SQL. There are three parts of PL/SQL subprogram. Declaration part This section starts with the DECLARE. This section is used for declarations of local types, variables and subprograms. This section is optional. Declarations are local to the block and cease to exist when the block…
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Overview of PL/SQL
1. Introduction In this tutorial, we’ll discuss about PL/SQL. We’ll also discuss its advantages, features and architecture. PL/SQL is the Oracle procedural extension of SQL. An SQL statement is a single statement and does not provide any functionality to group related SQL statements and treat the group as a unit. This problem can be solved…
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Natural key and surrogate key
1. Natural Key A natural key is a type of unique key in a database which has an equivalent in the external world outside the database. Database tables are used to represent entities in the real world. A natural key is some unique attribute or group of attributes of the real world entity which uniquely…