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Let us first create a table −mysql> create table DemoTable1795 ( Name varchar(20), DueDate date ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1795 values('John', '2018-07-21'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1795 values('Sam', '2019-10-21'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1795 values('Sam', '2019-01-10'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1795 values('Mike', '2018-12-31'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> ... Read More
For this, you can use TRUNCATE TABLE command. Let us first create a table −mysql> create table DemoTable1796 ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(20) ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1796(StudentName) values('Chris Brown'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1796(StudentName) values('David Miller'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1796(StudentName) values('John Doe'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statementmysql> select ... Read More
For this, you can use STR_TO_DATE(), since we have date records in the following format: 21/11/2019.Let us first create a table −mysql> create table DemoTable1808 ( AdmissionDate varchar(20) ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1808 values('21/11/2019'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1808 values('01/01/2018'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1808 values('26/09/2017'); Query OK, 1 row affected (0.00 sec)Display all records from the table using select statement −mysql> select * from DemoTable1808;This will ... 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
For this, you can use COUNT() along with GROUP BY MONTH(). To match with the current date, use CURRENT_DATE(). The current date is as follows −mysql> select curdate() ; +------------+ | curdate() | +------------+ | 2019-11-30 | +------------+ 1 row in set (0.00 sec)Let us first create a table −mysql> create table DemoTable1819 ( Name varchar(20), RegisteringDate datetime ); Query OK, 0 rows affected (0.00 sec)Insert some records in the table using insert command −mysql> insert into DemoTable1819 values('Chris', '2019-11-29 12:30:34'); Query OK, 1 row affected (0.00 sec) mysql> insert into DemoTable1819 ... Read More
To check for NULL or empty variable, use the IF condition. Let us create a stored procedure −mysql> delimiter // mysql> create procedure checkingForNullDemo(Name varchar(20)) begin if Name is NULL OR Name='' then select 'Adam Smith'; else select Name; end if ; end // Query OK, 0 rows affected (0.00 sec) mysql> delimiter ;Case 1When NULL is passed. Call the stored procedure using call commandmysql> call checkingForNullDemo(NULL);This will produce the following output −+------------+ | Adam Smith | +------------+ | Adam Smith | +------------+ 1 ... Read More
Java does not support multiple inheritance. This means that a class cannot extend more than one class. Therefore, following is illegal −Examplepublic class extends Animal, Mammal{}However, a class can implement one or more interfaces, which has helped Java get rid of the impossibility of multiple inheritance.The extends keyword is used once, and the parent interfaces are declared in a comma-separated list.For example, if the Hockey interface extended both Sports and Event, it would be declared as −Examplepublic interface Hockey extends Sports, Event
Follow the steps given below, to integrate Ant into Eclipse.Make sure that the build.xml is a part of your java project, and does not reside at a location that is external to the project.Enable Ant View by following Window > Show View > Other > Ant > Ant.Open Project Explorer, drag the build.xml into the Ant View.Your Ant view looks similar to –Clicking on the targets, build / clean / usage will run Ant with the target. Clicking "fax" will execute the default target - usage.The Ant Eclipse plugin also comes with a good editor for editing build.xml files. The ... Read More
All exception classes are subtypes of the java.lang.Exception class. The Exception class is a subclass of the Throwable class. Other than the Exception class there is another subclass called Error which is derived from the Throwable class.
The StringBuffer and StringBuilder classes are used when there is a necessity to make a lot of modifications to Strings of characters.Unlike Strings, objects of type StringBuffer and String builder can be modified over and over again without leaving behind a lot of new unused objects.The StringBuilder class was introduced as of Java 5 and the main difference between the StringBuffer and StringBuilder is that StringBuilder’s methods are not thread safe (not synchronized).It is recommended to use StringBuilder whenever possible because it is faster than StringBuffer. However, if the thread safety is necessary, the best option is StringBuffer objects.Read More