Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
MySQL Articles
Page 94 of 355
How does MySQL QUOTE() function work with comparison values?
When QUOTE() function used with WHERE clause then the output depends upon the comparison values returned by WHERE clause. Following example will exhibit it −Examplemysql> Select Name, ID, QUOTE(Subject)AS Subject from Student WHERE Subject = 'History'; +-------+------+-----------+ | Name | ID | Subject | +-------+------+-----------+ | Aarav | 2 | 'History' | +-------+------+-----------+ 1 row in set (0.00 sec)
Read MoreHow can we take a backup of the single database by using mysqldump client program?
By using mysqldump client program we can take the backup of a database into a file having the extension ‘.sql’. it can be understood with the help of following example −ExampleIn this example, with the help of mysqldump client program, we are taking the backup of a database named ‘tutorials’ in a file named ‘tutorials.sql’. The following command will do this −C:\mysql\bin>mysqldump -u root tutorials > tutorials.sqlThe above command will create a file named ‘turorials.sql’ in the bin folder of MySQL. This file will contain drop table, create a table and insert command for all the tables in the tutorials ...
Read MoreHow can we take a backup of multiple databases by using mysqldump client program?
By using mysql dump client program we can take the backup of multiple databases into a file having the extension ‘.sql’. It can be understood with the help of the following example −ExampleIn this example, with the help of mysql dump client program, we are taking the backup of two databases named ‘tutorials’ and ‘query1’ in a file named ‘tutorials_query1.sql’. The following command will do this −C:\mysql\bin>mysqldump -u root --databases tutorials query1 > tutorials_query1.sqlThe above command will create a file named tutorials_query1.sql which have the dump information of both the databases named tutorials and query1.
Read MoreHow can I restore a file created by mysqldump?
Suppose if we want to restore a file that has been created by mysqldump then we can restore in an existing database or in a new database after creating it. Then with the help of SOURCE statement, we can restore it. We can illustrate it by an example:ExampleIn this example, we are restoring the table named student_info.sql which has been dumped. It was basically in the database name ‘query’. Now we will restore it into a database named ‘tutorials’.mysql> Use Tutorials; Database changed mysql> SOURCE student_info.sql; Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected ...
Read MoreHow can we upload data into MySQL tables by using mysqlimport?
For uploading the data into MySQL tables by using mysqlimport we need to follow following steps −Step-1 − Creating the tablefirst of all, we need to have a table in which we want to upload the data. We can use CREATE TABLE statement for creating a MySQL table. For example, we created a table named ‘student_tbl’ as follows −mysql> DESCRIBE Student_tbl; +--------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------+------+-----+---------+-------+ | RollNo | int(11) | YES | | NULL | | | ...
Read MoreHow can we upload data into multiple MySQL tables by using mysqlimport?
With the help of mysqlimport we can upload data into multiple MySQL tables. It is illustrated in the example below −ExampleSuppose we want to upload the following data from two data files namely student1_tbl.txt −1 Saurav 11th 2 Sahil 11th 3 Digvijay 11thAnd House.txt1 Furniture 2 Television 3 RefrigeratorFollowings are MySQL tables into which we want to upload the above data −mysql> DESCRIBE Student1_tbl; +--------+-------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +--------+-------------+------+-----+---------+-------+ | RollNo | int(11) ...
Read MoreIn what cases, we cannot use MySQL TRIM() function?
Actually for using MySQL TRIM() function we must have to know the string which we want to trim from the original string. This becomes the major drawback of TRIM() in the cases where we want to trim the strings having different values. For example, suppose we want to get the output after trimming the last two characters from the strings but every string is having different characters at last two places.Examplemysql> Select * from Employee; +------+----------------+------------+-----------------+ | Id | Name | Address | Department | +------+----------------+------------+-----------------+ | 100 | Raman ...
Read MoreSecurity, Integrity and Authorization in DBMS
Database SecurityDatabase security has many different layers, but the key aspects are:AuthenticationUser authentication is to make sure that the person accessing the database is who he claims to be. Authentication can be done at the operating system level or even the database level itself. Many authentication systems such as retina scanners or bio-metrics are used to make sure unauthorized people cannot access the database.AuthorizationAuthorization is a privilege provided by the Database Administer. Users of the database can only view the contents they are authorized to view. The rest of the database is out of bounds to them.The different permissions for ...
Read MoreCentralized Database Management System
A centralized database is stored at a single location such as a mainframe computer. It is maintained and modified from that location only and usually accessed using an internet connection such as a LAN or WAN. The centralized database is used by organisations such as colleges, companies, banks etc.As can be seen from the above diagram, all the information for the organisation is stored in a single database. This database is known as the centralized database.AdvantagesSome advantages of Centralized Database Management System are −The data integrity is maximised as the whole database is stored at a single physical location. This ...
Read MoreN-ary Relationship in Database
A relationship is an important part of any Entity relationship diagram as it shows the relation between two different entities. In an n - ary relationship, the n shows the number of entities in the relationship. It can be anything but the most popular relationships are unary, binary and ternary where the number of entities respectively are one, two and three.More information about Unary, Binary and Ternary relationships is as follows −Unary RelationshipWhen there is a relationship between two entities of the same type, it is known as a unary or recursive relationship. This means that the relationship is between ...
Read More