SEQUEL widely known as SQL, Structured Query Language is the most popular standard language to work on databases. We can perform tons of operations using SQL which includes creating a database, storing data in the form of tables, modify, extract and lot more. There are different versions of SQL like MYSQL, PostgreSQL, Oracle, SQL lite, etc. There are some important commands in SQL which can be broadly categorized into DDL, DML, DCL, TCL, DQL....
The join condition for the natural join is basically an EQUIJOIN of all columns with same name. To specify arbitrary conditions or specify columns to join, the ON Clause is used....
The PostgreSQL ORDER BY clause is used to sort the result query set returned by the SELECT statement. As the query set returned by the SELECT statement has no specific order, one can use the ORDER BY clause in the SELECT statement to sort the results in the desired manner....
1. COMMIT-COMMIT in SQL is a transaction control language that is used to permanently save the changes done in the transaction in tables/databases. The database cannot regain its previous state after its execution of commit....
In SQL, Pivot and Unpivot are relational operators that are used to transform one table into another in order to achieve more simpler view of table. Conventionally we can say that Pivot operator converts the rows data of the table into the column data. The Unpivot operator does the opposite that is it transform the column based data into rows....
SQL MERGE Statement combines INSERT, DELETE, and UPDATE statements into one single query....
SQL ORDER BY clause sorts the result of the SELECT statement either in ascending or descending order....
WHERE and HAVING clauses play an important role in refining the result set of a query. While both clauses are used for filtering data, they serve distinct purposes and are applied at different stages of query execution. Let’s explore the details of each and their differences with examples....
A PARTITION BY clause is used to partition rows of table into groups. It is useful when we have to perform a calculation on individual rows of a group using other rows of that group....
In PostgreSQL ,The continue statement is used to skip the current iteration prematurely and directly move on to the next iteration. The continue statement is used in conjecture with all types of loops including unconditional loops, while loops and for loops....
In SQL, a Cartesian Join is also called a Cross Join, it performs the cartesian product of records of two or more joined tables. A Cartesian product matches each row of one table to every other row of another table, only when the WHERE condition is not specified in the query. In case the WHERE condition is specified then the Cartesian Join works as an Inner Join....
