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You can use alter command. The syntax is as follows −ALTER TABLE yourTableName MODIFY COLUMN yourColumNam enum(yourOldValue1, yourOldValue2, ....N, yourNewValue1, yourNewValue2, ....N);To understand the above syntax, let us first create a table. The query to create a table is as follows −mysql> create table EnumDemo -> ( -> AllColors enum('RED', 'GREEN') -> ); Query OK, 0 rows affected (0.66 sec)Now you have two members in AllColors of enum type. If you want to add more members to your enum type, use the following query −mysql> alter table EnumDemo -> modify column ... Read More
Every iPhone application needs some icons that are displayed when certain events occur, like when some new notification comes, or the icon for home screen or the icon that is displayed on spotlight.All these icons have different size properties but apart from their size there are some common properties they have. Let’s see them first.The icons should be in .png formatThe icons should be flat and should not have transparency.The images should be squared, without any round corners.For any iOS device the icons size for app store is 1024px * 1024pxOther app icon sizes are usually bases on 1x, 2x ... Read More
To select rows where a column is null, you can use IS NULL from MySQL with the help of where clause.The syntax is as follows −select *from yourTableName where yourColumnName IS NULL;Let us first create a table to understand the concept −mysql> create table NULLDemo1 -> ( -> StudentId int, -> StudentName varchar(100) -> ); Query OK, 0 rows affected (1.48 sec)Inserting records into the table. The query to insert records is as follows −mysql> insert into NULLDemo1 values(NULL, 'John'); Query OK, 1 row affected (0.25 sec) mysql> ... Read More
You can select all records that are 10 minutes within current timestamp using the following syntax−SELECT *FROM yourTableName WHERE yourColumnName > = DATE_SUB(NOW(), INTERVAL 10 MINUTE);To understand the above syntax, let us create a table. The query to create a table is as follows−mysql> create table users -> ( -> Id int NOT NULL AUTO_INCREMENT, -> UserName varchar(20), -> UserLastseen datetime, -> PRIMARY KEY(Id) -> ); Query OK, 0 rows affected (0.91 sec)Insert some records in the table using insert command. The query is as follows−mysql> insert into users(UserName, UserLastseen) values('Larry', '2019-01-15 02−45−00'); Query ... Read More
To set user variable from result of query in MySQL, you need to move that variable into the assignment.To understand the above concept, let us first create a table. The query to create a table is as follows −mysql> create table UserVariable -> ( -> Id int, -> Name varchar(100) -> ); Query OK, 0 rows affected (0.53 sec)Insert some records in the table using insert command. The query is as follows −mysql> insert into UserVariable values(101, 'John'); Query OK, 1 row affected (0.17 sec) mysql> insert ... Read More
Now let us see a program of Intel 8085 Microprocessor. This program will convert gray code to binary code.Problem StatementWrite an assembly language program for 8085 to convert gray code to binary code. The data is stored at address 8200H & store the result at memory location 8201H.DiscussionHere we are loading the number from memory and in each step we are performing right shift, and XOR the intermediate result with the previous one. Thus we are getting the result. In the following demonstration you can get the logic.C 1110 1011 (A) (EBH) 07H 0111 ... Read More
You can use CASE statement to get the results that match some expressions−SELECT *FROM yourTableName WHERE CASE WHEN yourColumnName1 = yourValue1 THEN 1 ELSE 0 END + CASE WHEN yourColumnName2 = yourValue2 THEN 1 ELSE 0 END + CASE WHEN yourColumnName3 = yourValue3 THEN 1 ELSE 0 END + . . CASE WHEN yourColumnNameN = yourValueN THEN 1 ELSE 0 END > = 3;To understand the above syntax, let us create a table. The query to create a table is as follows −mysql> create table UserInformation -> ( -> Id int NOT NULL AUTO_INCREMENT, ... Read More
Elliptic curve cryptography is used to implement public key cryptography. It was discovered by Victor Miller of IBM and Neil Koblitz of the University of Washington in the year 1985. ECC popularly used an acronym for Elliptic Curve Cryptography. It is based on the latest mathematics and delivers a relatively more secure foundation than the first generation public key cryptography systems for example RSA.Elliptic CurvesIn 1985, cryptographic algorithms were proposed based on elliptic curves. An elliptic curve is the set of points that satisfy a specific mathematical equation. They are symmetrical.UsesWebsites make extensive use of ECC to secure customers’ hypertext ... Read More
You can use select case statement for this. The syntax is as follows.select yourColumnName1, yourColumnName2, ...N, case when yourColumnName=1 then 'true' else 'false' end as anyVariableName from yourTableName;To understand the above syntax, let us create a table. The query to create a table is as follows.mysql> create table selectReturnDemo -> ( -> Id int, -> Name varchar(100), -> isGreaterthan18 tinyint(1) -> ); Query OK, 0 rows affected (0.62 sec)Now you can insert some records in the table using insert command. The query is as follows.mysql> insert into selectReturnDemo values(1, 'Carol', 0); Query OK, 1 row affected (0.23 sec) mysql> ... Read More
Today’s age is a technology-driven age. Mobile phones are the most used gadget at the moment. Be it rich or poor, young or old, mobiles have become a part and parcel for each one of us. However, the cell phone has a lot of adverse effects like back pain, stress, irritation, and depression, radiations harming us leading to different nervous disorders and the others.Limiting Mobile Phone UsagePlace the phone down on a hard surface if one is texting. One can even hold the phone in one hand and text with the other. This will increase the time of texting and ... Read More