MySQLi Articles - Page 33 of 341

To find distinct number of specific items, use COUNT() along with GROUP BY clause. Let us first create a table −mysql> create table DemoTable1854      (      Name varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1854 values('John-Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1854 values('Chris-Brown'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1854 values('Adam-Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1854 values('John-Doe'); Query OK, 1 row affected (0.00 sec) mysql> insert into ... Read More

If you try to compare string to int, MySQL won’t raise an error because it converts string to int. Let us first create a table −mysql> create table DemoTable1852      (      Value1 varchar(20),      Value2 int      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1852 values('1John', 1); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1852 values('John', 1); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1852 values('1', 1); Query OK, 1 row affected (0.00 sec) mysql> insert into ... Read More

For this, use DELETE command. Let us first create a table −mysql> create table DemoTable1851      (      DueDate datetime      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1851 values('2019-12-03 21:30:35'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1851 values('2019-12-03 21:45:00'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1851 values('2019-12-03 21:34:00'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1851; This will produce the following output −+---------------------+ | ... Read More

Let us first create a table −mysql> create table DemoTable1850      (      OrderStatus varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1850 values('Yes'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1850 values('No'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1850 values('Yes'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1850 values('Yes'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1850; This will produce the ... Read More

For this, you can use IFNULL() or COALESCE(). Let us first create a table −mysql> create table DemoTable1849      (      ClientFirstName varchar(20),      ClientLastName varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1849 values('John', NULL); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1849 values(NULL, 'Miller'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1849 values(NULL, NULL); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1849 values('Chris', 'Brown'); Query OK, 1 row affected (0.00 sec)Display all ... Read More

Let us first create a table −mysql> create table DemoTable1847      (      GameStatus ENUM('PENDING', 'COMPLETED', 'CANCELLED')      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1847 values('PENDING'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1847 values('COMPLETED'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1847 values('CANCELLED'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1847; This will produce the following output −+------------+ | GameStatus | +------------+ | PENDING   ... Read More

For this, you can use the concept of INTERVAL and DATE_SUB(). Let us first create a table −mysql> create table DemoTable1845      (      ArrivalDate date      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1845 values('2019-12-02'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1845 values('2019-11-18'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1845 values('2019-12-18'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1845 values('2019-12-25'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1845 values('2019-11-15'); Query ... Read More

For this, you can use CONCAT() and round(). Let us first create a table −mysql> create table DemoTable1844      (      Number int,      TotalNumber int      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1844 values(50, 500); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1844 values(80, 500); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1844 values(98, 500); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1844 values(45, 500); Query OK, 1 row affected (0.00 sec)Display all ... Read More

For this, use MySQL YEAR() function. Let us first create a table −mysql> create table DemoTable1843      (      StartDate date,      EndDate date      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1843 values('2019-01-21', '2019-10-12'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1843 values('2018-10-12', '2018-12-31'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1843 values('2016-04-01', '2017-05-02'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1843;This will produce the ... Read More

To multiply with NULL row, you can use COALESCE(). Let us first create a table −mysql> create table DemoTable1842      (      NumberOfItems int,      Amount int      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1842 values(10, 40); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1842 values(20, 5); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1842 values(NULL, 10); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1842;This ... Read More