The GROUP BY is a clause in the SQL language, and when used with the SELECT statement, it is used to group rows that have the same values in specified columns into summary rows. This is particularly useful when you want to perform aggregate functions, such as counting, summing, averaging, or finding the maximum/minimum values, […]
A SELF-JOIN in MySQL occurs when a table is joined with itself. This can be useful in scenarios where you want to compare rows within the same table or establish relationships between rows based on certain conditions. A self-join is typically used when you have a hierarchical structure or when you need to compare related […]
The CROSS JOIN in MySQL is a type of join operation that combines each row from one table with every row from another table. Unlike other join types, such as INNER JOIN or LEFT JOIN, CROSS JOIN doesn’t require any matching criteria between the tables. It simply generates the Cartesian product of the two tables […]
A RIGHT JOIN in MySQL is a type of join operation that combines rows from two tables based on a specified condition, and it returns all the rows from the right table (the second table mentioned in the query) and the matched rows from the left table (the first table mentioned in the query). If […]
A LEFT JOIN in MySQL is a type of join operation that combines rows from two or more tables based on a specified condition and includes unmatched rows from the left table. This means that even if there is no match in the right table, all the rows from the left table will still be […]
In MySQL, an INNER JOIN is a type of join operation that combines rows from two or more tables based on a related column between them. The result set includes only the rows that have matching values in the specified columns. Syntax The basic syntax of an INNER JOIN is as follows: SELECT columns FROM […]
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