Tutorials on Structured Query Language

There are mainly two type of indexes in SQL, Clustered index and non clustered index. The differences between these two indexes is very important from SQL performance perspective. One table can have only one clustered index, but it can have many non-clustered index. (Approximately 250). A clustered index determines how data is stored physically in … Read more

Yes. You can use the column alias in the ORDER BY instead of WHERE clause for sorting. No, it is not possible to sort a column using a column alias directly in SQL. Column aliases are typically used for renaming columns or for creating more readable output in the result set, but they cannot be … Read more

SQL or Structured Query Language is a language which is used to communicate with a relational database. It provides a way to manipulate and create databases. On the other hand, PL/SQL is a dialect of SQL which is used to enhance the capabilities of SQL. It was developed by Oracle Corporation in the early 90’s. … Read more

SQL or Structured Query Language is a language which is used to communicate with a relational database. It provides a way to manipulate and create databases. On the other hand, MySQL and Microsoft’s SQL Server both are relational database management systems that use SQL as their standard relational database language. MySQL is available for free … Read more

Non-Clustered Index: The reason to create non-clustered index is searching the data. We well know that clustered indexes are created automatically primary keys are generated, but non-clustered indexes are created when multiple joins conditions and various filters are used in the query. Non-Clustered Index does not alter the physical order of the table and maintains … Read more