Use SUBSTRING_INDEX to select everything before @ in an email-id −select substring_index(yourColumnName, '@', 1) from yourTableName;Let us first create a table −mysql> create table DemoTable -> ( -> EmployeeMailId varchar(100) -> ); Query OK, 0 rows affected (0.52 sec)Insert some records in the table using insert command −mysql> insert into ... Read More

To update an existing table, use UPDATE. With that, to set the current date, use the CURDATE() method −update yourTableName set yourCoumnName=CURDATE();Let us first create a table −mysql> create table DemoTable -> ( -> DueDate datetime -> ); Query OK, 0 rows affected (0.58 sec)Insert some records in the table ... Read More

For this, you can use aggregate function COUNT(*). Let us first create a table in let’s say database “web” −mysql> create table DemoTable1    -> (    -> Value int    -> ); Query OK, 0 rows affected (0.60 sec)Insert some records in the table using insert command −mysql> insert ... Read More

Use ALTER command for this. Let us first create a table −mysql> create table DemoTable -> ( -> StudentName varchar(100) -> ); Query OK, 0 rows affected (0.46 sec)Here is the query to insert auto_increment −mysql> alter table DemoTable ADD COLUMN StudentId int NOT NULL; Query OK, 0 rows affected ... Read More

Use LENGTH() for this. Let us first create a table −mysql> create table DemoTable -> ( -> Value text -> ); Query OK, 0 rows affected (0.74 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('10, 20, 10, 30, 10, 40, 50, 40'); Query OK, ... Read More

Following is the syntax −show create view yourViewName;Let us first create a table −mysql> create table DemoTable -> ( -> StudentName varchar(20) -> ); Query OK, 0 rows affected (0.56 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.14 ... Read More

Let’s say you need to get the difference between dates (JoiningDate – EndDate) of a month i.e. days to calculate the salary. The daily-wage salary is let’s say 300; therefore for 20 days, it will 6000. In the same way, for 27 days, it will be 8100.For our example, let ... Read More

Use concat() for this. Let us first create a table −mysql> create table DemoTable    -> (    -> FirstName varchar(30),    -> LastName varchar(30)    -> ); Query OK, 0 rows affected (0.49 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Chris', 'Brown'); Query ... Read More

To set values on the basis of conditions, use IF() method. Let us first create a table −mysql> create table DemoTable    -> (    -> Age int    -> ); Query OK, 0 rows affected (0.55 sec)Insert some records in the table using insert command −mysql> insert into DemoTable ... Read More

To order by timestamp, use the ORDER BY as in the following syntax −select *from yourTableName ORDER BY STR_TO_DATE(`yourColumnName`, '%m/%d/%Y%h:%i:%s %p');Let us first create a table −mysql> create table DemoTable    -> (    -> `timestamp` varchar(100)    -> ); Query OK, 0 rows affected (0.56 sec)Insert some records in ... Read More