For this, you can use group_concat() with aggregate function. Let us first create a table −mysql> create table DemoTable1869      (      Id int,      Subject varchar(20 ),      Name varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1869 values(100, 'MySQL', 'John'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1869 values(100, 'MongoDB', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1869 values(101, 'MySQL', 'Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1869 values(101, ... Read More

For this, you can use the concept of user defined variable. Let us first create a table −mysql> create table DemoTable1868      (      Value int      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1868 values(10); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1868 values(20); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1868 values(30); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1868 values(40); Query OK, 1 row affected (0.00 sec)Display all records from the table using ... Read More

To list all variables initialized by SET operator, the syntax is as follows −select * from performance_schema.user_variables_by_thread;Here is the query to set the variable −mysql> set @FirstName='John'; Query OK, 0 rows affected (0.00 sec) mysql> set @LastName='Doe'; Query OK, 0 rows affected (0.00 sec)Here is the query to display the list of all variables initialized by SET operator. This list includes the variables set above −mysql> select * from performance_schema.user_variables_by_thread;This will produce the following output −+-----------+---------------+----------------+ | THREAD_ID | VARIABLE_NAME | VARIABLE_VALUE | +-----------+---------------+----------------+ |       120 | TotalAmount   |           5000 | ... Read More

For this, use date_add() with interval command. Let us first create a table −mysql> create table DemoTable1867      (      ArrivalTime datetime      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1867 values('2019-10-12 12:34:45'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1867 values('2019-10-12 10:04:15'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1867 values('2019-10-12 11:00:23'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1867; This will produce the following output ... Read More

For this, use FIND_IN_SET(). Let us first create a table −mysql> create table DemoTable1866      (      Value1 int,      ListOfValues varchar(100)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1866 values(56, '78, 56, 98, 95'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1866 values(103, '103, 90, 102, 104'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1866 values(77, '34, 45, 77, 78'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> ... Read More

To round, use MySQL ROUND() function. Let us first create a table −mysql> create table DemoTable1865      (      Value1 int,      Value2 int      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1865 values(40, 60); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1865 values(100, 400); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1865 values(545, 896); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1865;This will produce the ... Read More

Use @anyVariableName to assign the result of a query into a variable. Let us first create a table −mysql> create table DemoTable1864      (      Id int,      FirstName varchar(20),      LastName varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1864 values(101, 'Chris', 'Brown'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1864 values(102, 'David', 'Miller'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1864 values(103, 'Adam', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into ... Read More

To set default value for empty row, use the concept of COALESCE(). Let us first create a table −mysql> create table DemoTable1863      (      FirstName varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1863 values('Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1863 values(NULL); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1863 values('David'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1863 values(NULL); Query OK, 1 row affected (0.00 sec)Display all records from the table ... Read More

For this, use the concept of GREATEST(). Let us first create a table −mysql> create table DemoTable1862      (      Value1 int,      Value2 int,      Value3 int,      Value4 int      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1862 values(43, 34, 56, 42); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1862 values(NULL, 78, 65, NULL); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1862 values(110, NULL, 78, NULL); Query OK, 1 row affected (0.00 sec)Display all ... Read More

For this, you can use GROUP BY HAVING with subquery. Let us first create a table −mysql> create table DemoTable1861      (      Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,      Name varchar(20),      Marks int      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1861(Name, Marks) values('John', 45); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1861(Name, Marks) values('Chris', 74); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1861(Name, Marks) values('David', 89); Query OK, 1 row affected (0.00 sec) ... Read More