Let us first create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    EmployeeSalary int ); Query OK, 0 rows affected (1.68 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(EmployeeSalary) values(12000); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable(EmployeeSalary) values(20000); Query OK, 1 row affected (0.55 sec) mysql> insert into DemoTable(EmployeeSalary) values(11500); Query OK, 1 row affected (0.94 sec) mysql> insert into DemoTable(EmployeeSalary) values(15500); Query OK, 1 row affected (0.44 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce ... Read More

Let’s say the current date is 2019-08-20. Now for our example, we will create a table −mysql> create table DemoTable (    ProductStatus tinyint(1),    ProductExpiryDate date ); Query OK, 0 rows affected (1.03 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(0, '2019-06-12'); Query OK, 1 row affected (0.43 sec) mysql> insert into DemoTable values(0, '2019-10-11'); Query OK, 1 row affected (0.38 sec) mysql> insert into DemoTable values(0, '2018-07-24'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(0, '2018-09-05'); Query OK, 1 row affected (0.27 sec)Display all records from the table ... Read More

Use GROUP BY to group records, whereas SUM() function is used to add. Let us first create a table −mysql> create table DemoTable (    Name varchar(40),    Subject varchar(40),    Marks int ); Query OK, 0 rows affected (2.89 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 'MySQL', 76); Query OK, 1 row affected (0.32 sec) mysql> insert into DemoTable values('Sam', 'MongoDB', 86); Query OK, 1 row affected (0.39 sec) mysql> insert into DemoTable values('Mike', 'MySQL', 98); Query OK, 1 row affected (0.46 sec) mysql> insert into DemoTable values('David', 'Java', 93); Query OK, ... Read More

Use a variable to store SUM(total) and update it with the UPDATE command. Let us first create a table −mysql> create table DemoTable (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    Value int ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(Value) values(70); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable(Value) values(100); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(Value) values(150); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable(Value) values(250); Query OK, 1 row affected (0.14 sec) mysql> ... Read More

Let us first create a table −mysql> create table DemoTable (    CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    ProductAmount int ); Query OK, 0 rows affected (0.61 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(ProductAmount) values(5000); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(ProductAmount) values(6000); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable(ProductAmount) values(7000); Query OK, 1 row affected (0.26 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+------------+---------------+ | CustomerId | ProductAmount | +------------+---------------+ | ... Read More

Let us first create a table −mysql> create table DemoTable1 (    Name varchar(40) ); Query OK, 0 rows affected (0.81 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1 values('Chris'); Query OK, 1 row affected (0.48 sec) mysql> insert into DemoTable1 values('Robert'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable1 values('Mike'); Query OK, 1 row affected (0.10 sec)Display all records from the table using select statement −mysql> select *from DemoTable1;This will produce the following output −+--------+ | Name   | +--------+ | Chris  | | Robert | | Mike   | +--------+ ... Read More

The COALESCE() finds the NON-NULL value first If it finds the same in the beginning, then it returns, otherwise moves ahead to check NON-NULL value.Let us first create a table −mysql> create table DemoTable (    Number1 int,    Number2 int ); Query OK, 0 rows affected (5.48 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(100, 200); Query OK, 1 row affected (0.40 sec) mysql> insert into DemoTable values(NULL, 50); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values(10, NULL); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable ... Read More

To find the latest dates, order the date records with ORDER BY DESC. Since we want only 3 dates, use LIMIT 3.Let us first create a table −mysql> create table DemoTable (    AdmissionDate date ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('2019-09-04'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values('2019-08-10'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values('2019-09-21'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable values('2019-09-18'); Query OK, 1 row affected (0.17 sec) mysql> ... Read More

Let us first create a table −mysql> create table DemoTable (    StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY,    StudentName varchar(30) ); Query OK, 0 rows affected (0.70 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(StudentName) values('John Smith'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(StudentName) values('David Miller'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(StudentName) values('Carol Taylor'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(StudentName) values('John Doe'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(StudentName) values('Chris Brown'); Query OK, 1 row ... Read More

Let us first create a table −mysql> create table DemoTable (    Number text ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('7364746464, -'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable values('-, 8909094556'); Query OK, 1 row affected (0.23 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the following output −+--------------+ | Number | +--------------+ | 7364746464, - | | -, 8909094556 | +--------------+ 2 rows in set (0.00 sec)Following is ... Read More