Category Archives: sql

SQL – UNION Operator Table of content The SQL UNION Operator The SQL UNION operator is used to combine data from multiple tables by eliminating duplicate rows (if any). To use the UNION operator on multiple tables, all these tables must be union compatible. And they are said to be union compatible if and only […]

SQL – ORDER BY Clause Table of content The SQL ORDER BY Clause The SQL ORDER BY clause is used to sort the data in either ascending or descending order, based on one or more columns. This clause can sort data by a single column or by multiple columns. Sorting by multiple columns can be […]

SQL – Delete Table Table of content The SQL DELETE is a command of Data Manipulation Language (DML), so it does not delete or modify the table structure but it delete only the data contained within the table. Therefore, any constraints, indexes, or triggers defined in the table will still exist after you delete data […]