Found 4378 Articles for MySQL

What happens to MySQL temporary tables if MySQL session is ended?

seetha
Updated on 30-Jul-2019 22:30:21

89 Views

Temporary table would be deleted if MySQL session terminates. After login again, on issuing the SELECT command we will find no data available in the database. Even our temporary table will not exist.

How can we create MySQL views with column list?

Anjana
Updated on 22-Jun-2020 13:06:25

168 Views

As we know that while creating a view, providing the list of columns is optional. But if we are providing the name of the columns while creating the view then the number of names in the list of columns must be the same as the number of columns retrieved by the SELECT statement.ExampleThe following example will illustrate by creating the views with column list −mysql> Select * from student_detail; +-----------+-------------+------------+ | Studentid | StudentName | address    | +-----------+-------------+------------+ | 100       | Gaurav      | Delhi      | | 101       | Raman ... Read More

How can we create a MySQL view based on another existing view?

George John
Updated on 22-Jun-2020 13:07:56

279 Views

In MySQL, we can create a view that is based on another existing view. To make it understand we are having the view ‘Info’ with the following data −mysql> Create view info AS Select Id, Name, Subject FROM student_info; Query OK, 0 rows affected (0.11 sec) mysql> Select * from Info; +------+---------+------------+ | Id | Name | Subject | +------+---------+------------+ | 101 | YashPal | History | | 105 | Gaurav | Literature | | 125 | Raman | Computers | | NULL | Ram | Computers | +------+---------+------------+ 4 rows in set (0.00 sec)Now, with the help of ... Read More

How can we see MySQL temporary tables in the list of tables?

Priya Pallavi
Updated on 22-Jun-2020 13:10:17

177 Views

As we know that we can see the list of tables in a database with the help of SHOW TABLES statement. But MySQL temporary tables are not stored in this list or in other words we can say that we cannot see the temporary tables with the help of SHOW TABLES statement. To illustrate it we are using the following example −ExampleIn this example, we are trying to get the temporary table named ‘SalesSummary’ from SHOW TABLES statement as follows −mysql> SHOW TABLES LIKE '%Sales%'; Empty set (0.00 sec) mysql> SHOW TABLES LIKE '%SalesSummary%'; Empty set (0.00 sec)The above ... Read More

How can we create MySQL views without any column list?

Samual Sam
Updated on 22-Jun-2020 13:09:29

115 Views

While creating a view, providing the list of columns is optional. The following example will illustrate by creating the views without any column list −mysql> Select * from student_detail; +-----------+-------------+------------+ | Studentid | StudentName | address    | +-----------+-------------+------------+ |       100 | Gaurav      | Delhi      | |       101 | Raman       | Shimla     | |       103 | Rahul       | Jaipur     | |       104 | Ram         | Chandigarh | |     ... Read More

What are the different privileges required for using views?

Lakshmi Srinivas
Updated on 22-Jun-2020 13:20:14

110 Views

Following privileges are required for a different kind of CREATE, REPLACE, DROP, ACCESS, UPDATE etc. of usage of views − CREATE VIEW Privilege − CREATE VIEW privilege is required to create a view. Along with this we must have sufficient privileges, like SELECT, INSERT or UPDATE, for accessing the tables to which the view definition refers. DROP VIEW Privilege − We require DROP VIEW privileges for using OR REPLACE clause, DROP VIEW statement and also for using ALTER VIEW statement. SELECT Privilege − We must have SELECT privileges for selecting from a view. INSERT, DELETE or UPDATE Privileges − Actually for an updateable view ... Read More

What are the prerequisites before starting writing and using MySQL views?

Arjun Thakur
Updated on 22-Jun-2020 12:56:03

165 Views

MySQL VersionAs we know that MySQL 5 introduced views, hence, first of all, we need to check for the version of MySQL before starting writing and using stored procedures. It can be done with the following query −mysql> Select VERSION(); +-----------+ | VERSION() | +-----------+ | 5.7.20    | +-----------+ 1 row in set (0.10 sec)Privileges for current userActually CREATE VIEW statement requires the CREATE VIEW privilege. Privileges for the current user can be checked with the following query −mysql> SHOW PRIVILEGESSelecting a databaseBefore creating a view we must have to select a database from the available databases. It can ... Read More

What are the limitations of using MySQL views?

karthikeya Boyini
Updated on 22-Jun-2020 12:55:02

1K+ Views

In spite of various benefits of using views there are following limitations on using MySQL views − Can’t create an index of views − In MySQL, we cannot create an index on views. It is because indexes are not utilized when we query data against the views. MySQL invalidates the view − Suppose, if we drop or rename tables to which a view references, rather than issuing an error MySQL invalidate the view. We can use the CHECK TABLE statement to check whether the view is valid or not. MySQL views cannot be updateable in some situations − Actually, the simple view can ... Read More

What are the benefits of using MySQL views as compared to selecting data directly from MySQL base tables?

Ankith Reddy
Updated on 22-Jun-2020 12:57:20

1K+ Views

As we know that views are definitions built on the top of other tables or views and stored in the database. Followings are benefits of using MySQL views as compared to selecting data directly from MySQL base tablesSimplify data accessThe use of views simplifies the data access because of the following reasons −A view can be used to perform a calculation and display its result. For example, a view definition that invokes aggregate functions can be used to display a summary.With the help of views, we can select a restricted set of rows by means of an appropriate WHERE clause ... Read More

What do you mean by database view and how do MySQL views work?

Swarali Sree
Updated on 22-Jun-2020 12:58:19

283 Views

A database view is nothing more than an SQL statement that is stored in the database with an associated name. A view is actually a composition of a table in the form of a predefined SQL query.A view can contain all rows of a table or select rows from a table. A MySQL view can be created from one or many tables which depend on the written MySQL query to create a view.Views, which are a type of virtual tables allow users to do the following −Structure data in a way that users or classes of users find natural or ... Read More

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