Category Archives: sql

SQL – NOT NULL Constraint Table of content In a table, columns can typically accept NULL values by default. However, if you want to ensure that a particular column does not contain NULL values, you need to add the NOT NULL constraint/condition on that column. The SQL NOT NULL Constraint The NOT NULL constraint in […]

SQL – Group By Clause Table of content The SQL GROUP BY Clause The SQL GROUP BY clause is used in conjunction with the SELECT statement to arrange identical data into groups. This clause follows the WHERE clause in a SELECT statement and precedes the ORDER BY and HAVING clauses (if they exist). The main […]

SQL – BETWEEN Operator Table of content The SQL BETWEEN Operator The BETWEEN operator is a logical operator in SQL, that is used to retrieve the data within a specified range. The retrieved values can be integers, characters, or dates. You can use the BETWEEN operator to replace a combination of “greater than equal AND […]