To count the same value of each row, use COUNT(*) along with GROUP BY clause. Let us first create a table −mysql> create table DemoTable1818      (      Id int,      Name varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1818 values(10, 'Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1818 values(11, 'Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1818 values(11, 'Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1818 values(12, 'Chris'); Query ... Read More

To pass multiple ids to single parameter, use FIND_IN_SET(). Let us first create a table −mysql> create table  DemoTable1817      (      EmployeeName varchar(20),      CountryName varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1817 values('Chris', 'AUS'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1817 values('David', 'UK'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1817 values('Bob', 'US'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1817;This ... Read More

Following is the syntax to match date with date() function and updating a column −update yourTableName set yourColumnName=yourValue where date(yourColumnName)=curdate();Let us first create a table −mysql> create table DemoTable1816      (      Name varchar(20),      JoiningDate datetime      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1816 values('Chris', '2019-11-29 12:34:50'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1816 values('David', '2019-11-30 11:00:00'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1816 values('Mike', '2018-11-30 10:20:30'); Query OK, 1 row affected (0.00 sec)Display ... Read More

To randomly select, use ORDER BY RAND(). To select only 2 values, use LIMIT 2 in MySQL. Let us first create a table −mysql> create table DemoTable1815      (      Question text      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1815 values('What is your name?'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1815 values('What is your college name?'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1815 values('What is your nick name?'); Query OK, 1 row affected (0.00 sec) mysql> ... Read More

To implement DOUBLE in MySQL, the syntax is as follows −create table yourTableName      (      yourColumnName double(5, 2) unsigned );Let us first create a table −mysql> create table DemoTable1814      (      Amount double(5, 2) unsigned      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1814 values(1.98); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1814 values(100.24); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1814 values(198.50); Query OK, 1 row affected (0.00 sec)Display all records from the table ... Read More

For this, you can use GRANT SELECT statement as in the below syntax −GRANT SELECT ON *.* TO 'yourUserName'@'yourHostName';First list all the user names along with host −mysql> select user, host from mysql.user;This will produce the following output −+------------------+-----------+ | user             |      host | +------------------+-----------+ | Bob              |         % | | Charlie          |         % | | Robert           |         % | | User2       ... Read More

To implement if-else, the syntax is as follows −if yourCondition then      yourStatement1;     else     yourStatement2;     end if ;To understand the above concept for if-else in a stored procedure, let us create a stored procedure −mysql> delimiter // mysql> create procedure If_else_stored_demo(value int)      begin      if value > 1000 then      select "your value is greater than 1000";      else      select "your value is less than or equal to 1000";      end if ;      end      // Query OK, 0 rows affected (0.00 ... Read More

For this, use UNION ALL. Let us first create a table −mysql> create table DemoTable1813      (      Name1 varchar(20),      Name2 varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1813 values('John', 'Chris'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1813 values('Adam', 'Robert'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1813 values('Mike', 'Sam'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1813;This will produce the following ... Read More

To extract column name and type, use INFORMATION_SCHEMA.COLUMNS −select concat(column_name, '=', data_type) as anyAliasName from information_schema.columns where table_schema= yourDatabaseName and table_name= yourTableName;Let us first create a table −mysql> create table DemoTable1812      (      Id int,      FirstName varchar(20),      Age int,      isMarried boolean,      status ENUM('ACTIVE', 'INACTIVE')      ); Query OK, 0 rows affected (0.00 sec)Here is the query to extract column name and type from MySQL:mysql> select concat(column_name, '=', data_type) as COLUMNNAMEANDTYPE from information_schema.columns      where table_schema= 'web' and table_name= 'DemoTable1812';This will produce the following output −+-------------------+ | COLUMNNAMEANDTYPE ... Read More

Let us first create a table −mysql> create table DemoTable1811      (      FirstName varchar(20),      LastName varchar(20)      ); Query OK, 0 rows affected (0.00 sec)Here is the query to add indexmysql> alter table DemoTable1811 ADD UNIQUE unique_index_first_last_name(FirstName, LastName); Query OK, 0 rows affected (0.00 sec) Records: 0  Duplicates: 0  Warnings: 0Insert some records in the table using insert command −mysql> insert into DemoTable1811 values('John', 'Smith'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1811 values('John', 'Doe'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1811 values('Adam', 'Smith'); Query OK, 1 ... Read More