You can add unique key to existing table with the help of alter command. The syntax is as follows −ALTER TABLE yourTableName ADD CONSTRAINT yourConstraintName UNIQUE(yourColumnName1, yourColumnName2, ............N);To understand the above concept, let us create a table with some columns. The query to create a table −mysql> create table MovieCollectionDemo ... Read More

Appcaches are used by the web browser to specify what files exist on your site that is relevant to the particular page the browser is visiting.Safari follows the AppCache standard more strictly and sees a request for a web address that is not in the AppCache.To avoid the requests to ... Read More

For this, use Google Maps API to perform reverse geocoding.Geocoding refers to translating a human-readable address into a location on a map.The process of doing the converse, translating a location on the map into a human-readable address, is known as reverse geocoding.ExampleLet us see an example to set latitude and longitude ... Read More

No, HTML5 does not allow you to interact with local client files directly. You can use drag and drop or FileSystem API for this.ExampleLet us see an example of drag and drop on a web browser using HTML5 −                   ... Read More

Use the flex-direction property with column value to set the flex-items verticallyYou can try to run the following code to implement the column value:ExampleLive Demo                    .mycontainer {             display: flex;         ... Read More

For optimization, change the zindex of the frame. This layer the images on top of each other to solve the flickering because while redrawing the last frame is still visible.Keep incrementing the zindex value of the latest frame.Note − You need to reset the zindex again, and it may have ... Read More

Use the tag in HTML to add the glossary definitions. The HTML tag is used for declaring a definition list. This tag is used within tag.A definition list is similar to other lists but in a definition list, each list item contains two entries; a term and ... Read More

Grid Container in CSS has grid items. These items are placed inside rows and columns. Let us create aCSS Grid container and set the number of columns in a Grid:ExampleLive Demo                    .container {             ... Read More

To select elements, use the element selector. You can try to run the following code to select elements:ExampleLive Demo                    p {             color: blue;             background-color: orange;          }                     Demo Website       Learning       Tutorials on web dev, programming, database, networking, etc.       Every tutorials has lessons with illustrations and figures.    

In C++, it is faster to process a sorted array than an unsorted array because of branch prediction. In computer architecture, a branch prediction determines whether a conditional branch (jump) in the instruction flow of a program is likely to be taken or not.Let’s take an example −if(arr[i] > 50) ... Read More