Found 4219 Articles for MySQLi

In this case, the output of ASCII() function depends on the condition that whether we are providing NULL as a string or we are providing simply NULL to it. Following example will demonstrate the difference −mysql> SELECT ASCII(null); +-------------+ | ASCII(null) | +-------------+ | NULL        | +-------------+ 1 row in set (0.00 sec) mysql> SELECT ASCII('null'); +---------------+ | ASCII('null') | +---------------+ | 110           | +---------------+ 1 row in set (0.00 sec) mysql> Select ASCII(NULL); +-------------+ | ASCII(NULL) | +-------------+ | NULL        | +-------------+ 1 row in set ... Read More

MySQL AUTO_INCREMENT value starts from 1 but we can change it with the help of following two ways −With the help of ALTER TABLE query We can use ALTER TABLE query to change the staring value of AUTO_INCREMENT as follows −ALTER TABLE table_name AUTO_INCREMENT = value;ExampleSuppose we have created a table having column ‘id’ as AUTO_INCREMENT. Now if we will insert the values in it then the sequence number would start from 1 as you can see this in following queries −mysql> Create Table EMP(id int NOT NULL PRIMARY KEY AUTO_INCREMENT, NAME VARCHAR(10)); Query OK, 0 rows affected (0.07 sec) ... Read More

When the AUTO_INCREMENT column reaches the upper limit of data type then the subsequent effort to generate the sequence number fails. That is why it is advised to use a large enough integer data type for the AUTO_INCREMENT column to hold the maximum sequence value required by us. For example, if we will use TINYINT then AUTO_INCREMENT would be able to generate only 127 sequence numbers and in case of UNSIGNED TINYINT, this value can be extended up to 255.

In this case, it means we are providing an empty string as an argument to the ASCII() function. It will return 0 on providing empty string.Examplemysql> Select ASCII(''); +-----------+ | ASCII('') | +-----------+ |     0     | +-----------+ 1 row in set (0.00 sec)

String function ASCII() in MySQL returns the ASCII number code of the specific character.SyntaxASCII(str)Here, str, the argument of ASCII() function, is the string whose ASCII value of the first character to be retrieved.It is pertinent to mention here that it will return the number code the left the most character i.e. first character of the string given as argument.Examplemysql> SELECT ASCII('A') as 'ASCII VALUE OF CAPITAL A'; +--------------------------+ | ASCII VALUE OF CAPITAL A | +--------------------------+ | 65                       | +--------------------------+ 1 row in set (0.00 sec) mysql> SELECT ... Read More

As we know that MySQL LAST_INSERT_ID() function returns the latest generated sequence number but in case of multiple row-insert it would return the sequence number generated by the foremost inserted row.Examplemysql> Insert into Student(Name) values('Ram'), ('Mohan'), ('Aryan'); Query OK, 3 rows affected (0.03 sec) Records: 3 Duplicates: 0 Warnings: 0The query above inserts three values in Student table with the help of Multiple-row insert query. The value of Column ‘Id’ can be checked with the help of the following query −mysql> Select * from Student; +----+-------+ | Id | Name  | +----+-------+ | 1 | Raman  | | 2 | ... Read More

MySQL LAST_INSERT_ID() function is used to obtain the most recent generated sequence number by AUTO_INCREMENT.ExampleIn this example, we are creating a table named ‘Student’ having an AUTO_INCREMENT column. We insert two values in the column ‘Name’ and when we use INSERT_LAST_ID() function then it returns the most recent generated sequence number i.e. 2.mysql> Create table Student(Id INT PRIMARY KEY NOT NULL AUTO_INCREMENT, Name Varchar(5)); Query OK, 0 rows affected (0.13 sec) mysql> Insert into student(Name) Values('Raman'); Query OK, 1 row affected (0.06 sec) mysql> Insert into student(Name) Values('Rahul'); Query OK, 1 row affected (0.07 sec) mysql> Select* ... Read More

With the help of INSERT INTO command, a new row can be inserted into a table.SyntaxINSERT INTO table_name values(value1, value2, …)ExampleSuppose we have a table named ‘Employee’ with three columns ‘Emp_id’, ‘Emp_name’ and ‘Emp_Sal’ then with the help of following query we can add new rows to the table −mysql> INSERT INTO Employee values(110, 'Aarav', 50000); Query OK, 1 row affected (0.07 sec) mysql> INSERT INTO Employee values(200, 'Raman', 28000); Query OK, 1 row affected (0.10 sec) mysql> Select * from Employee; +---------+-------------+-----------+ | Emp_id  | Emp_name    | Emp_sal   | +---------+-------------+-----------+ | 110     |Aarav ... Read More

For inserting data into a MySQL table we need to use INSERT INTO command. We must have to specify values for all the columns of the table in INSERT INTO command.SyntaxINSERT INTO table_name values(value1, value2, …)ExampleSuppose we have a table named ‘Student’ with three columns ‘RollNo’, ‘Name’ and ‘Class’ then with the help of following query we can add new rows to the table −mysql> INSERT INTO Student values(50, 'Harshit', ’B.tech’); Query OK, 1 row affected (0.07 sec) mysql> INSERT INTO Student values(56, 'Amit', ’M.tech’); Query OK, 1 row affected (0.05 sec) mysql> Select * from Student; +---------+-------------+-----------+ ... Read More

We can use either TRUNCATE statement or DROP statement to delete all the rows from the table. It can also be done with the help of DELETE statement but in that case WHERE clause must identify all the rows of the table. As we know that both TRUNCATE and DELETE statement will not delete the structure of the table but still it is better to use TRUNCATE statement rather than DELETE statement. DROP statement will delete table’s structure also. Syntax TRUNCATE statement TRUNCATE table table_name: Syntax DROP statement DROP table table_name: