Found 4219 Articles for MySQLi

In MySQL, we can combine two or more strings along with a separator by using CONCAT_WS() function. The syntax of this function is CONCAT_WS(Separator, String1, String2, …, StringN)Here, the arguments of CONCAT_WS functions are Separator and the strings which need to be concatenated along with that separator as a single string. Separator except for numeric value must enclose within quotes.Examplemysql> Select CONCAT_WS('.', 'www', 'tutorialspoint', 'com'); +---------------------------------------------+ | CONCAT_WS('.', 'www', 'tutorialspoint', 'com') | +---------------------------------------------+ | www.tutorialspoint.com                      | +---------------------------------------------+ 1 row in set (0.00 sec)In this example above, we can see that the separator ... Read More

Suppose if we are trying to add the numbers having non-numeric text before them, then MySQL simply evaluate the value of such number as 0. Following example will exhibit this −Examplemysql> Select 'Kg 1525' + 'Oz 200'As Total; +-------+ | Total | +-------+ | 0     | +-------+ 1 row in set, 2 warnings (0.00 sec) mysql> Select 'Kg 1525' + '200'As Total; +-------+ | Total | +-------+ | 200   | +-------+ 1 row in set, 1 warning (0.00 sec)

The following MySQL statement can find out the storage engine used for ‘Student’ table in database named ‘tutorial’ −mysql> SELECT ENGINE FROM information_schema.TABLES   -> WHERE TABLE_SCHEMA = 'tutorial'   -> AND TABLE_NAME = 'Student'; +--------+ | ENGINE | +--------+ | MyISAM | +--------+ 1 row in set (0.13 sec)

While creating a MySQL table, the storage engine can be specified as follows −mysql> CREATE TABLE Student(id INTEGER PRIMARY KEY, Name VARCHAR(15)) -> ENGINE = 'MyISAM'; Query OK, 0 rows affected (0.28 sec)The ENGINE keyword specifies the storage engine used for this particular table.

Suppose if we are trying to add the numbers having non-numeric text after them, then MySQL simply discard the non-numeric text and evaluates the addition of numeric values along with warnings. Following example will exhibit this −Examplemysql> Select '1525 Kg' + '200 Oz'As Total; +-------+ | Total | +-------+ | 1725  | +-------+ 1 row in set, 2 warnings (0.00 sec)

If we are trying to add two numbers that are contained in quotes, means we are treating the string as a number. In this case, MySQL converts the value into the closet numeric equivalent and evaluates the result. Following example will demonstrate it.Examplemysql> Select '1525' + '200'As Total; +-------+ | Total | +-------+ | 1725  | +-------+ 1 row in set (0.00 sec)

MySQL cannot perform a case-sensitive comparison when comparing characters. It can be illustrated with the following example from table ‘Employee’ having the following data −mysql> Select * from Employee; +----+--------+--------+ | ID | Name   | Salary | +----+--------+--------+ | 1  | Gaurav | 50000  | | 2  | Rahul  | 20000  | | 3  | Advik  | 25000  | | 4  | Aarav  | 65000  | | 5  | Ram    | 20000  | | 6  | Mohan  | 30000  | | 7  | Aryan  | NULL   | | 8  | Vinay  | NULL   | +----+--------+--------+ 8 rows in set (0.09 sec)The result set of the following query shows that MySQL is not case sensitive when comparing characters.mysql> Select * from Employee WHERE Name IN ('gaurav','RAM'); +----+--------+--------+ | ID | Name   | Salary | +----+--------+--------+ | 1  | Gaurav | 50000  | | 5  | Ram    | 20000  | +----+--------+--------+ 2 rows in set (0.00 sec)

As we know that MySQL is not case-sensitive while comparing characters but it can be changed i.e. MySQL can perform case-sensitive string comparison if we will use BINARY keyword before the expression. Actually, BINARY keyword instructs MySQL to compare the characters in the string using their underlying ASCII values rather than just their letters. It can be illustrated with the following example from table ‘Employee’ having the following data −mysql> Select * from Employee; +----+--------+--------+ | ID | Name   | Salary | +----+--------+--------+ | 1  | Gaurav | 50000  | | 2  | Rahul  | 20000  | | 3 ... Read More

Actually, both MySQL IFNULL() and NULLIF() functions are having an almost same syntax as given below −The syntax of IFNULL()IFNULL(expression1, expression2)The syntax of NULLIF()NULLIF(expression1, expression2)They can be distinguished in the way they return the first argument as result. IFNULL() function will return the first argument as a result if it is not NULL and NULLIF() function will return the first argument as a result if both the arguments are not same.mysql> Select IFNULL('Ram', 'Shyam'); +-----------------------+ | IFNULL('Ram', 'Shyam') | +-----------------------+ | Ram                   | +-----------------------+ 1 row in set (0.00 sec) mysql> Select ... Read More

Once we get connected to the MySQL server, it is required to select a database to work with. This is because there might be more than one database available with the MySQL Server.It is very simple to select a database from the mysql> prompt. We can use SQL command ‘use’ to select a database. To illustrate it we are selecting the database named ‘Tutorials’ in the following example −Example[root@host]# mysql -u root -p Enter password:****** mysql> use TUTORIALS; Database changed mysql>Now, we have selected the TUTORIALS database and all the subsequent operations will be performed on the TUTORIALS database.Read More