Where WHERE clause specifies search conditions for the rows returned by the Query and limits rows to a meaningful set. Group By GROUP BY clause works on the rows returned by the previous step #1 (WHERE clause). This clause summaries identical rows into a single/distinct
Read More…

DELETE: Removes Someor All rows from a table. A WHEREclause can be used to remove some rows. If no WHERE condition is specified, all rows will be removed. Causes all DELETE triggers on the table to fire. It removes rows row-by-row one at a time and records an entry in the
Read More…

The major difference between MyISAM and InnoDB is in referential integrity and transactions. There are also other difference such as locking, rollbacks, and full-text searches. Referential Integrity Referential integrity ensures that relationships between tables remains consistent. More specifically, this means when a table (e.g. Listings)
Read More…

Advantages of InnoDB InnoDB should be used where data integrity comes a priority because it inherently takes care of them by the help of relationship constraints and transactions. Faster in write-intensive (inserts, updates) tables because it utilizes row-level locking and only hold up changes to
Read More…

What is a Storage Engine? A storage engine is a software that is used by a database management system to create, read, and update data from a database. Most DBMS use APIs (Application Programming Interface) to enable interactions of users with the storage engines. There
Read More…

KEY is normally a synonym for INDEX so it’s also called indexes. KEYS are used for speeding up queries. Keys are used to enforce referential integrity in your database. Primary Key: A primary key is a column or a set of columns that uniquely identifies
Read More…

First Normal form (1NF): A relation is said to be in 1NF if it has only single valued attributes, neither repeating nor arrays are permitted. 2NF (Second Normal Form) Rules Rule 1- Be in 1NF Rule 2- Single Column Primary Key It is clear that
Read More…