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Articles by AmitDiwan
Page 736 of 840
Count the same value of each row in a MySQL column?
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 MorePassing Multiple ids to single parameter in MySQL?
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 MoreMySQL randomly select 2 values from column values?
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 MoreImplement and set DOUBLE length in MySQL
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 MoreHow to GRANT SELECT ON all tables in all databases on a server with MySQL?
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 MoreHow to select and display a list of values in one column that are available in two different MySQL columns?
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 MoreHow to extract column name and type from MySQL?
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 MoreAdding unique constraint to ALTER TABLE in MySQL
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 MoreFetch a specific column value (name) in MySQL
To fetch a specific column value, use LIKE clause. Let us first create a table −mysql> create table DemoTable1809 ( Name varchar(20) ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1809 values('John'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1809 values('David'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1809 values('Mike'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1809 values('Johnson'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement ...
Read MoreDisplay all the column values in a single row separated by comma in MySQL?
For this, use GROUP_CONCAT() and CONCAT(). Let us first create a table −mysql> create table DemoTable1807 ( Id int ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1807 values(101); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1807 values(102); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1807 values(103); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1807;This will produce the following output −+------+ | Id | ...
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