Category: SQL

The SQL MAX function is a built-in function in SQL (Structured Query Language) that is used to return the maximum value of a given column in a database table. The MAX function can be used with any data type including numeric, date, and string. Syntax The syntax of the MAX function is as follows: SELECT…(Continue Reading)

The SQL COUNT function is a widely used aggregate function in SQL (Structured Query Language) that allows you to count the number of rows in a table or the number of records that meet a specific condition in a table. It is used to return the number of rows or non-null values in a column.…(Continue Reading)

The SQL AVG function is used to calculate the average value of a set of numeric data values in a database table. It is a commonly used SQL aggregate function that can be applied to a single column or multiple columns of a table. Syntax The syntax for the AVG function is as follows: SELECT…(Continue Reading)

In SQL, a self join is a type of join where a table is joined with itself. It is useful when you have a single table that contains related data that you want to compare or analyze. To perform a self join, you need to use two or more instances of the same table and…(Continue Reading)

In SQL, a CROSS JOIN is a type of join operation that returns the Cartesian product of two or more tables. In other words, it combines each row from one table with every row from another table, resulting in a new table with a number of rows equal to the product of the number of…(Continue Reading)

In SQL, a FULL JOIN is a type of join operation that combines the rows from two tables, including both matching and non-matching rows. It is also known as a full outer join. To perform a FULL JOIN, you need to specify two tables and a join condition that determines how the two tables should…(Continue Reading)

In SQL, a RIGHT JOIN is a type of join operation used to combine data from two tables based on a common column, but it returns all the rows from the right table and matching rows from the left table. This means that even if there are no matching rows in the left table, the…(Continue Reading)

SQL LEFT JOIN, also known as LEFT OUTER JOIN, is a type of join operation used in relational databases to combine data from two tables based on a common column or key. The result set of a LEFT JOIN includes all the rows from the left table and the matching rows from the right table,…(Continue Reading)

SQL INNER JOIN is a type of JOIN operation used to combine rows from two or more tables based on a matching condition between the tables. It is one of the most commonly used JOIN types in SQL, along with LEFT JOIN and RIGHT JOIN. Syntax The syntax for an INNER JOIN is as follows:…(Continue Reading)

A check constraint is a type of constraint that is used in SQL to ensure that a specified condition is met before data is added or modified in a table. Check constraints are used to enforce business rules or logic on a table column or a set of columns. A check constraint is defined as…(Continue Reading)