Tag Archives: SQLServerPediaSyndication

SQL Triggers – An Introduction

By | December 8, 2018

SQL Triggers – An Introduction Contents Introduction Magic Tables Difference between Stored Procedure and Trigger DML Triggers After Triggers Syntax of the After trigger Example of After Trigger for Insert Example of After Trigger for Delete Example of After Trigger for Update Instead of Triggers DDL Triggers DDL Trigger for Create Table DDL Trigger for… Read More »

Isolation levels in SQL Server

By | August 19, 2012

Isolation levels :- Isolation level is required to isolate a resource and protect it from other transactions. This is achieved with the help of locks but what locks are needed and how they can be established is decided on the isolation level set on the database level. If low level of Isolation is set, it… Read More »

SQL Server Functions- An Introduction

By | August 2, 2011

SQL FUNCTION: –    Function in a database can be defined as the code segment consisting of a logical group of SQL statements which takes some input arguments (if required), run in a sequential order and returns the output either in the form of a single value or in the form of a table.Through this… Read More »

Difference between Subquery, Nested Subquery and Correlated Subquery

By | September 29, 2009

Difference between Subquery, Nested Subquery and Correlated Subquery Query Query can be defined as a way to inquire the data from the database. It is used to extract the data from one table or multiple tables depending upon the user needs. Suppose we have a two tables Student and courses whose structure is given below:-… Read More »

Sql server Constraints – Primary Key, Foreign Key, Unique Key, Not Null, Check Constraints

By | August 19, 2009

Introduction A constraint is a property that is assigned to a column or a group of columns to prevent incorrect or corrupt data from entering into the tables. These constraints ensure the accuracy and reliability of the data into the tables. This article will tell about the Sql server Constraints – Primary Key, Foreign Key,… Read More »