Souy Soeng

Understanding SQL DELETE The SQL DELETE statement is used to remove rows from a table. It allows you to delete specific rows based on conditions or …

Understanding the SQL ANY Operator The SQL ANY operator is used in conjunction with comparison operators (like = , < , > , <= , >= , an…

Understanding SQL ALL The SQL the  ALL operator is used with comparison operators ( = , != , < , > , <= , >= ) to compare a value agains…

Understanding the SQL EXISTS Operator The SQL EXISTS operator is used to check the existence of records returned by a subquery. It returns TRUE if…

Understanding SQL MINUS The SQL MINUS operator is used to compare two SELECT queries and return the rows that are present in the first query but no…

Understanding SQL Subqueries A subquery, also known as an inner query or nested query, is a query within another SQL query. The subquery provides dat…

SQL Correlated Subquery A correlated subquery in SQL is a subquery that refers to columns from the outer query. It is evaluated once for every row p…

SQL CUBE The CUBE operator in SQL is an extension of the GROUP BY clause. It allows you to generate subtotals for all combinations of columns speci…

SQL UNION The UNION operator in SQL combines the result sets of two or more SELECT queries into a single result set. It removes duplicate rows by d…

SQL ROLLUP The ROLLUP operator in SQL is an extension of the GROUP BY clause. It enables hierarchical or cumulative subtotals and a grand total in …

SQL INTERSECT The INTERSECT operator in SQL returns the common rows (intersection) between two or more SELECT queries. The output includes only row…

Understanding SQL HAVING The SQL HAVING clause is used to filter groups of data after aggregation. Unlike the WHERE clause, which filters rows befo…

SQL GROUPING SETS SQL GROUPING SETS The GROUPING SETS clause in SQL allows you to create multiple groupings in a single query, making it easier to…

SQL GROUP BY The GROUP BY statement in SQL is used to arrange identical data into groups. It is typically used with aggregate functions (like COUNT …

Understanding the SQL MAX() Function The MAX() function in SQL is an aggregate function used to retrieve the largest value in a column. It is benef…

Understanding SQL COUNT The SQL COUNT function is an aggregate function that returns the total number of rows in a table or the number of rows that …

What is SQL SUM()? The SUM() function in SQL calculates the total sum of a numeric column. It is one of the aggregate functions in SQL and is often …

What is SQL MIN()? The MIN() function in SQL is an aggregate function that returns the smallest (minimum) value from a specified column. It is commo…

What is SQL AVG()? The AVG() function in SQL is used to calculate the average (mean) value of a numeric column. It is a part of SQL's aggregate …

Understanding SQL CROSS JOIN The SQL CROSS JOIN is a type of join that returns the Cartesian product of two tables. This means that it will combine …

Understanding SQL SELF JOIN A SQL SELF JOIN is a join operation where a table is joined with itself. This is useful when a table contains a hierarch…

What Are SQL Aggregate Functions? SQL aggregate functions perform calculations on a set of values and return a single value. These functions are comm…

Understanding the SQL CASE Statement The SQL CASE statement is a powerful conditional expression that allows you to execute logic within an SQL que…

Understanding SQL ALIAS An SQL ALIAS is a temporary name assigned to a table or a column in a query. It improves readability and convenience, especi…

Understanding SQL INNER JOIN The SQL INNER JOIN is a type of join that retrieves records from two or more tables based on a related column. It ret…

Understanding SQL LEFT JOIN The SQL LEFT JOIN (or LEFT OUTER JOIN ) retrieves all records from the left table (first table) and the matched records …

Understanding SQL FULL OUTER JOIN The SQL FULL OUTER JOIN retrieves records from both the left and right tables. It returns all rows when there is a…

Understanding SQL IS NULL In SQL, the IS NULL operator is used to check if a value in a column is NULL . A NULL value represents missing, undefined…

Understanding the SQL NOT Operator The SQL NOT operator is used to negate a condition in a query. It is a logical operator that returns TRUE if th…

What is the SQL IN Operator? The IN operator in SQL is used to filter rows based on whether a column value matches any value in a specified list. I…