Insert NULL or Empty String in MySQL

Arjun Thakur
Updated on 24-Jun-2020 14:10:49

2K+ Views

In innoDB, NULL occupies less space as compared to empty string. Also, the NULL length is null while length of the empty string is 0.To understand this, a table is created with the help of create command which is given as follows −mysql> CREATE table DemoEmptyAndNULL -> ( -> Message varchar(100) -> ); Query OK, 0 rows affected (0.49 sec)After creating the table successfully, an empty record is inserted into the table with the help of insert command which is as follows −mysql> INSERT into DemoEmptyAndNULL values(' '); Query OK, 1 row affected (0.17 sec)After inserting the record, we can ... Read More

Mobile Safari Location Sharing Prompt in HTML

Samual Sam
Updated on 24-Jun-2020 14:10:27

138 Views

When we have a requirement in which we want to track the latest locations for a user only when they are in a certain area, then we write separate code for it. The code to determine when to prompt the user to share location in HTML is as follows -if (frstTime) { //First time        navigator.getCurrentPosition(function (coordinates) {             if (coordsAreInTheBox) {                    storeCoordsForUser();                    navigator.watchPosition();             }        }); ... Read More

Find Non-ASCII Characters in MySQL

Ankith Reddy
Updated on 24-Jun-2020 14:10:12

2K+ Views

Non ASCII characters are characters such as the pound symbol(£), trademark symbol, plusminus symbol etc. To find the non-ASCII characters from the table, the following steps are required −First a table is created with the help of the create command which is given as follows −mysql> CREATE table NonASciiDemo -> ( -> NonAScii varchar(100) -> ); Query OK, 0 rows affected (0.61 sec)After that the records are inserted into the table with the help of the insert command which is as follows −mysql> INSERT into NonASciiDemo values('-, -'); Query OK, 1 row affected (0.18 sec) mysql> INSERT into NonASciiDemo ... Read More

Mouse Event Not Triggered on HTML5 Canvas - How to Solve It

Arjun Thakur
Updated on 24-Jun-2020 14:09:51

519 Views

To trigger mouse event we can add −-webkit-transform: translate3d(0, 0, 0)In addition to this canvas can also be styled.Another way is to add a listener in the event mousemove,canvas.addEventListener("mousemove", this.checkMouseLocation.bind(this, this.inputs), false);By adding this listener, we can easily trigger a mouse move event in HTML5.

Stop Running a MySQL Query

Chandu yadav
Updated on 24-Jun-2020 14:09:41

1K+ Views

Before stopping a running query of MySQL, first we need to see how many processes are running with the help of show command.The query for that is given as follows −mysql> show processlist;After executing the above query, we will get the output with some id’s. This is given as follows −+----+-----------------+-----------------+----------+---------+-------+------------------------+------------------+ | Id | User | Host | db | Command | Time | State | Info | +----+-----------------+-----------------+----------+---------+-------+------------------------+------------------+ | 4 | event_scheduler | localhost | NULL | Daemon | 71034 | Waiting on empty queue | NULL | | 8 | Manish | localhost:53496 | business | Query | ... Read More

Upload from Local Drive to Local Filesystem in HTML with Filesystem API

vanithasree
Updated on 24-Jun-2020 14:09:06

239 Views

To upload from local drive to the local file system, we can use −Webkitdirectory attribute on − This allows the user to select a directory by the appropriate dialog box.Filesystem API is a sandboxed filesystem, which allows us to store files on client’s machine.File API allows us to read files. Files are accessible by elementAll of the above is working fine in Google Chrome.WebKit directory is a much better option among these. Use the following for directory −webkitRequestFileSystem(    window.TEMPORARY, 5 * 1024 * 1024, function(_fs) {       fs = _fs;    }, ErrAbove, err and fs are −var fs, err = function(err) {    throw err; };

Set Button on Image with CSS

Nancy Den
Updated on 24-Jun-2020 14:08:35

2K+ Views

You can try to run the following code to set button on an image:ExampleLive Demo                    .box {             position: relative;             width: 100%;             max-width: 250px;          }          .box img {             width: 100%;             height: auto;          }          .box .btn {             position: absolute;             top: 50%;             left: 50%;             transform: translate(-50%, -50%);          }                                        Button          

Difference Between Schema and Database in MySQL

George John
Updated on 24-Jun-2020 14:07:57

5K+ Views

In MySQL, schema is synonymous with database. As the query is written to create the database, similarly the query can be written to create the schema.Logical structure can be used by the schema to store data while memory component can be used by the database to store data. Also, a schema is collection of tables while a database is a collection of schema.To clarify this concept, a database and a schema are created. The steps for this are as follows −First, a database is created with the following syntax −create database yourDatabaseName;The above syntax is used in a query as ... Read More

Variables in CSS

Chandu yadav
Updated on 24-Jun-2020 14:07:02

107 Views

Variables in CSS are used to add custom property values to your web page. Set a custom name of the property and set value for it.You can try to run the following code to implement variables in CSS to change the background and text colorExampleLive Demo                    :root {             --my-bg-color: blue;             --my-color: white;          }          #demo {             background-color: var(--my-bg-color);             color: var(--my-color);          }                     Heading One       This is demo text. This is demo text. This is demo text.          This is demo text. This is demo text. This is demo text. This is demo text.          This is demo text. This is demo text.                

Get Max of Two Values in MySQL

Arjun Thakur
Updated on 24-Jun-2020 14:07:00

1K+ Views

To get the maximum of two values in MySQL, we can use the predefined function “greatest”. The syntax of greatest() function is as follows −SELECT greatest(value1, value2);Applying the above query, To get the maximum value from two values. The query is as follows −Case 1We are giving both the values int.mysql> SELECT greatest(100, -300); After executing the above query, we will get the following output+--------------------+ | greatest(100, -300) | +--------------------+ | 100 | +--------------------+ 1 row in set (0.00 sec)Case 2We are giving both the ... Read More

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