SQL Foreign key April 5, 2019 by Ranga Babu In this article let us review different ways to create a SQL foreign key, rules on updates and deletes, enabling foreign key constraints, disabling foreign key constraints and not for replication in foreign keys. Read more »
SQL index overview and strategy November 27, 2018 by Bojan Petrovic A SQL index is used to retrieve data from a database very fast. Indexing a table or view is, without a doubt, one of the best ways to improve the performance of queries and applications. A SQL index is a quick lookup table for finding records users need to search frequently. An index is small, fast, and optimized for quick lookups. It is very useful for connecting the relational tables and searching large tables. Read more »
Commonly used SQL Server Constraints: FOREIGN KEY, CHECK and DEFAULT October 31, 2017 by Ahmad Yaseen In the previous article Commonly used SQL Server Constraints: NOT NULL, UNIQUE and PRIMARY KEY, we described, in detail, the first three types of the SQL Server constraints; NOT NULL, UNIQUE and PRIMARY KEY. In this article, we will discuss the other three constraints; FOREIGN KEY, CHECK and DEFAULT by describing each one briefly and providing practical examples. Read more »
Commonly used SQL Server Constraints: NOT NULL, UNIQUE and PRIMARY KEY October 25, 2017 by Ahmad Yaseen SQL Server Constraints are predefined rules and restrictions that are enforced in a single column or multiple columns, regarding the values allowed in the columns, to maintain the integrity, accuracy, and reliability of that column’s data. In other words, if the inserted data meets the constraint rule, it will be inserted successfully. If the inserted data violates the defined constraint, the insert operation will be aborted. Read more »
The benefits, costs, and documentation of database constraints April 7, 2016 by Ed Pollack Constraints exist as a way to enforce or document rules within the database. How do they affect performance, and what are the benefits of using them? Read more »
