Category Archives: sql

SQL – NOT EQUAL Table of content The SQL NOT EQUAL Operator The SQL NOT EQUAL operator is used to compare two values and return true if they are not equal. It is represented by “<>” and “!=”. The difference between these two is that <> follows the ISO standard, but != doesn”t. So, it […]

SQL – IS NULL Table of content Let”s assume a table with NULL values in some of its fields. These fields indicate that no values are present in them. SQL allows users to create new records or modify existing ones without specifying a value for a field. If no value is provided, the field is […]

SQL – IS NOT NULL Table of content A NULL value indicates a missing or unknown value. It appears to be blank and does not contain any data. It is very important to understand that a NULL value is different than a zero value or a field that contains spaces. For checking null values we […]