Category Archives: sql

SQL – IN vs EXISTS Table of content In SQL, we use the IN operator to simplify queries and reduce the need for multiple OR conditions. It allows us to match a value against a list of values. On the other hand, the EXISTS operator checks whether one or more rows exist in a subquery […]

SQL – Null Functions Table of content SQL NULL functions are used to perform operations on NULL values that are stored in the database tables. A NULL value serves as a placeholder in the database when data is absent or the required information is unavailable. It is a flexible value not associated to any specific […]

SQL – Check Constraint Table of content The SQL CHECK Constraint The SQL CHECK constraint is used to add conditions on a column of a table. Once you add the check constraint on a column, it ensures that the data entered into the column meets the specified conditions. If a particular record does not meet […]