Description: The ‘Is Not Null’ condition in SQL is used to check if a column in a database contains a value. In the context of SQL, ‘null’ represents the absence of a value or an unknown data point. This condition is fundamental for ensuring data integrity and for performing effective queries. By using ‘Is Not Null’, developers can filter records that have valid values, which is especially useful in situations where complete and accurate information is required. For example, when conducting data analysis, it is common to want to exclude records that lack relevant information, such as email addresses or phone numbers. The ‘Is Not Null’ condition can be applied in various SQL clauses, such as in SELECT, WHERE, and HAVING statements, allowing users to obtain more specific and useful results. In summary, this condition is an essential tool in database management, helping users work with meaningful data and avoid errors that could arise from manipulating null values.
