Let us first create a table −mysql> create table DemoTable777 ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(100), StudentAge int ); Query OK, 0 rows affected (1.34 sec)Insert some records in the table using insert command −mysql> insert into DemoTable777(StudentName, StudentAge) values('Chris', 23); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable777(StudentName, StudentAge) values('Robert', 21); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable777(StudentName, StudentAge) values('Mike', 19); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable777(StudentName, StudentAge) values('Bob', 22); Query OK, 1 row ... Read More

Let’s say you have set column values as unique key and try to insert duplicate values in the table. This will lead to ERROR 1062 (23000): Duplicate entry.Let us first create a table -mysql> create table DemoTable776 (    FirstValue int,    SecondValue int,    unique key(FirstValue, SecondValue) ); Query OK, 0 rows affected (0.74 sec)Insert some records in the table using insert command. While inserting duplicate value, the same error arises as shown below -mysql> insert into DemoTable776 values(10, 20); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable776 values(10, 40); Query OK, 1 row affected (0.15 ... Read More

Let us first create a table −mysql> create table DemoTable775 ( FirstName varchar(100) ); Query OK, 0 rows affected (0.78 sec)Insert some records in the table using insert command −mysql> insert into DemoTable775 values('Adam') ; Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable775 values('Carol'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable775 values('John'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable775 values('Sam'); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable775 values('Adan'); Query OK, 1 row affected (0.15 sec)Display all records from the table using select statement −mysql> select ... Read More

The current date format is ‘YYYY-mm-dd’. To change current date format, you can use date_format().Let us first display the current date −mysql> select curdate();This will produce the following output −+------------+ | curdate() | +------------+ | 2019-08-08 | +------------+ 1 row in set (0.00 sec)Following is the query to change curdate() (current date) format −mysql> select date_format(curdate(), '%m/%d/%Y');This will produce the following output −+------------------------------------+ | date_format(curdate(), '%m/%d/%Y') | +------------------------------------+ | 08/08/2019                         | +------------------------------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable ... Read More

For this, use aggregate function SUM(). Within this method, multiply the row values. Let us first create a table −mysql> create table DemoTable(    ProductQuantity int,    ProductPrice int ); Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10, 9); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(6, 20); Query OK, 1 row affected (0.19 sec) mysql> insert into DemoTable values(7, 100); Query OK, 1 row affected (0.08 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following ... Read More

For this, use GROUP BY clause along with aggregate function SUM(). Let us first create a table −mysql> create table DemoTable(    Name varchar(100),    Score int ); Query OK, 0 rows affected (0.70 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Adam', 50); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Bob', 80); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('Adam', 70); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Adam', 10); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Carol', ... Read More

Let us first create a table −mysql> create table DemoTable(    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    CustomerName varchar(100) ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(CustomerName) values('Adam Smith'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(CustomerName) values('Chris Brown'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(CustomerName) values('David Miller'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(CustomerName) values('Carol Taylot'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable(CustomerName) values('Carol Taylor'); Query OK, 1 row affected ... Read More

For this, you can use CASE statement. Let us first create a table −mysql> create table DemoTable(    Id int,    Value int ); Query OK, 0 rows affected (0.51 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(10, 100); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(10, -110); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(10, 200); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(10, -678); Query OK, 1 row affected (0.17 sec)Display all records from the table using select statement −mysql> ... Read More

Let us first create a table −mysql> create table DemoTable(    EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    EmployeeName varchar(100),    JoiningDate date ); Query OK, 0 rows affected (0.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(EmployeeName, JoiningDate) values('Chris', '2019-01-21'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(EmployeeName, JoiningDate) values('Robert', '2016-12-01'); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(EmployeeName, JoiningDate) values('Mike', '2015-03-12'); Query OK, 1 row affected (0.12 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------------+--------------+-------------+ ... Read More

Let us first create a table −mysql> create table DemoTable(    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Name varchar(100) ); Query OK, 0 rows affected (0.47 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Name) values('John'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(Name) values('Bob'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(Name) values('Adam'); Query OK, 1 row affected (0.28 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+----+------+ | Id | Name | +----+------+ | 1 | ... Read More