You can use DISTINCT along with SUBSTRING_INDEX() to extract the filename extensions. Let us first create a table−mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    FileName text    ); Query OK, 0 rows affected (0.75 sec)Insert records in the table using insert command −mysql> insert into DemoTable(FileName) values('AddTwoValue.java'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(FileName) values('Image1.png'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(FileName) values('MultiplicationOfTwoNumbers.java'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable(FileName) values('Palindrome.c'); Query OK, 1 row affected (0.16 sec) mysql> insert ... Read More

Let us first create a table −mysql> create table DemoTable    (    Number float    ); Query OK, 0 rows affected (0.47 sec)Insert records in the table using insert command −mysql> insert into DemoTable values(1000); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(1); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable values(390); Query OK, 1 row affected (0.09 sec)Display all records from the table using select statement −mysql> ... Read More

Yes, we can use all of them in a single query. Let us first create a table −mysql> create table DemoTable    (    StudentId int,    StudentFirstName varchar(20),    StudentLastName varchar(20),    StudentAge int    ); Query OK, 0 rows affected (0.53 sec)Insert records in the table using insert command −mysql> insert into DemoTable values(100, 'John', 'Smith', 23); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(101, 'Carol', 'Taylor', 24); Query OK, 1 row affected (0.62 sec) mysql> insert into DemoTable values(103, 'John', 'Doe', 22); Query OK, 1 row affected (0.24 sec) mysql> insert into DemoTable ... Read More

To update column with random value, you can use the below syntax−update yourTableName set yourColumnName =round(1+rand()*100);The above syntax will generate a value between 1 to 100. Let us see an example and create a table−mysql> create table DemoTable    (    Number int    ); Query OK, 0 rows affected (0.46 sec)Insert records in the table using insert command −mysql> insert into DemoTable values(10); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable values(100); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable values(80); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(100000); ... Read More

You can use FORMAT() from MySQL to convert numbers to millions and billions format. Let us first create a table−mysql> create table DemoTable    (    Value BIGINT    ); Query OK, 0 rows affected (0.74 sec)Insert records in the table using insert command −mysql> insert into DemoTable values(78000000000); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(10000000000); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable values(90000000000); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(450600000000); Query OK, 1 row affected (0.41 sec)Display all records from the table using select statement ... Read More

To get the total number of rows in a MySQL database, you can use aggregate function SUM() along with inbuilt column TABLE_ROWS from INFORMATION_SCHEMA.TABLES.The syntax is as follows−SELECT SUM(TABLE_ROWS) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = database();Let’s say we are using the database with the name ‘sample’.Now we will get the total number of rows in a MySQL database−mysql> SELECT SUM(TABLE_ROWS) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA = database();This will produce the following output−+-----------------+ | SUM(TABLE_ROWS) | +-----------------+ | 2043 | +-----------------+ 1 row in set (22.11 sec)

You can exclude a specific record in SQL using not equal to operator(!=). Let us first create a table−mysql> create table DemoTable    (    Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,    ClientName varchar(20),    ClientCountryName varchar(10)    ); Query OK, 0 rows affected (0.64 sec)Insert records in the table using insert command −mysql> insert into DemoTable(ClientName, ClientCountryName) values('John', 'US'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(ClientName, ClientCountryName) values('David', 'AUS'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(ClientName, ClientCountryName) values('Mike', 'UK'); Query OK, 1 row affected (0.14 sec)Display all records from the ... Read More

In order to get last day of current year, you can use LAST_DAY() from MySQL. The syntax is as follows−SELECT LAST_DAY(DATE_ADD(CURDATE(), INTERVAL 12-MONTH(CURDATE()) MONTH));Let us implement the above syntax to know the last day of current year−mysql> SELECT LAST_DAY(DATE_ADD(CURDATE(), INTERVAL 12-MONTH(CURDATE()) MONTH));This will produce the following output −+-------------------------------------------------------------------+ | LAST_DAY(DATE_ADD(CURDATE(), INTERVAL 12-MONTH(CURDATE()) MONTH)) | +-------------------------------------------------------------------+ | 2019-12-31 | +-------------------------------------------------------------------+ 1 row in set (0.00 sec)

The IF() function returns a value based on a condition.The syntax is as follows−SELECT IF(yourCondition, yourMessageIfConditionBecomesTrue, yourMessageIfConditionBecomesFalse) from yourTableName; Let us first create a table: mysql> create table DemoTable    (    Value int    ); Query OK, 0 rows affected (0.60 sec)Insert records in the table using insert command −mysql> insert into DemoTable values(1000); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(2000); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(500); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable values(1100); Query OK, 1 row affected (0.16 sec)Display all records ... Read More

You can use ZEROFILL for column to fill in or pad with zeros. Let us first create a table−mysql> create table DemoTable    (    Number int    ); Query OK, 0 rows affected (0.58 sec)Following is the query to add zerofill attribute for Number column−mysql> alter table DemoTable change Number Number int(10) zerofill not null; Query OK, 0 rows affected (1.13 sec) Records: 0 Duplicates: 0 Warnings: 0Insert records in the table using insert command −mysql> insert into DemoTable values(1); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable values(12); Query OK, 1 row affected (0.53 sec) ... Read More