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JavaScript CookiesUsing JavaScript cookies is the most efficient method of remembering and tracking preferences, purchases, commissions, and other information required for better visitor experience or site statistics.PHP CookiesCookies are text files stored on the client computer and they are kept for tracking purpose. PHP transparently supports HTTP cookies.How JavaScript cookies work?Your server sends some data to the visitor's browser in the form of a cookie. The browser may accept the cookie. If it does, it is stored as a plain text record on the visitor's hard drive. Now, when the visitor arrives at another page on your site, the browser ... Read More
Methods are the functions that let the object do something or let something is done to it. There is a small difference between a function and a method – at a function is a standalone unit of statements and a method is attached to an object and can be referenced by this keyword.Methods are used for everything from displaying the contents of the object to the screen to performing complex mathematical operations on a group of local properties and parameters. Here’s an example showing how to use the write() method of the document object to write any content on the document.document.write("This ... Read More
To delete all cookies with JavaScript, you can try to run the following code. Here, we’re using an array and the split() method to get all the cookies and finally delete themExampleLive Demo var num = 1; function addCookie(){ document.cookie = num+" = "+num; num++; } function listCookies(){ var result = document.cookie; document.getElementById("list").innerHTML = result; } function removeCookies() { var res = document.cookie; var multiple = res.split(";"); for(var i = 0; i < multiple.length; i++) { var key = multiple[i].split("="); document.cookie = key[0]+" =; expires = Thu, 01 Jan 1970 00:00:00 UTC"; } } ADD LIST COOKIES REMOVE Cookies List
Use CREATE TABLE IF NOT EXISTS for this as shown in the below syntax −create table if not exists yourTableName ( yourColumnName1 dataType, yourColumnName2 dataType, yourColumnName3 dataType, . . N ) as select yourValue1 as yourColumnName1 , yourValue2 as yourColumnName2 , yourValue3 as yourColumnName3, .............................N;Let us first create a table and insert value if the table does not already exist −mysql> create table if not exists DemoTable ( id int, FirstName varchar(20), LastName varchar(20) ) as select 100 as id, 'John' as FirstName , 'Smith' as LastName; Query OK, 1 row ... Read More
Let us first create a table −mysql> create table DemoTable ( CustomerId int NOT NULL AUTO_INCREMENT PRIMARY KEY, ProductAmount int, CustomerCountryName varchar(10) ); Query OK, 0 rows affected (0.86 sec)Insert some records in the table using insert command −mysql> insert into DemoTable(ProductAmount, CustomerCountryName) values(190, 'US'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable(ProductAmount, CustomerCountryName) values(200, 'UK'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable(ProductAmount, CustomerCountryName) values(1500, 'AUS'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(ProductAmount, CustomerCountryName) values(2010, 'US'); Query OK, 1 row affected (0.13 sec) mysql> insert into ... Read More
To display a single quote text, use double quotes like if you want to write You’ve, then write You've while inserting i.e. with double-quotes. Let us first create a table −mysql> create table DemoTable ( Note text ); Query OK, 0 rows affected (0.57 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('You''ve seen the Taj? When?'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values('You''ve visited the US?'); Query OK, 1 row affected (0.16 sec)Display all records from the table using select statement −mysql> select *from DemoTable;This will produce the ... Read More
To update only blank cells to NULL, use NULLIF() in MySQL. Let us first create a table −mysql> create table DemoTable ( Name varchar(50) ); Query OK, 0 rows affected (1.73 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values('Mike'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values(''); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable values('David'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values(''); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('Mike'); Query OK, 1 row affected (0.15 ... Read More
Let us see the first syntax, which uses DISTINCT in MAX() −select max(DISTINCT yourColumnName) from yourTableName;The second syntax is as follows. It isn’t using DISTINCT −select max( yourColumnName) from yourTableName;NOTE − Both the above queries give the same result with or without a DISTINCT keyword. MySQL internally converts MAX(yourColumnName) to DISTINCT keyword.Let us now see an example and create a table −mysql> create table DemoTable ( Number int ); Query OK, 0 rows affected (1.50 sec)Insert some records in the table using insert command −mysql> insert into DemoTable values(80); Query OK, 1 row affected (0.09 sec) mysql> insert into ... Read More
To trigger a JavaScript click event, let us see the example of mouse hover.ExampleLive Demo Hover over the button. function display() { document.getElementById("test").click(); }
For this, use COALESCE(). Let us implement a stored procedure to check if the local variable is null −mysql> DELIMITER // mysql> CREATE PROCEDURE local_VariableDemo() BEGIN DECLARE value1 int; DECLARE value2 int; select value1, value2; select concat('After checking local variable is null the sum is = ', COALESCE(value1, 0)+COALESCE(value2, 0)); END // Query OK, 0 rows affected (0.19 sec) mysql> DELIMITER ;Call the stored procedure using CALL command −mysql> call local_VariableDemo();This will produce the following output −+--------+--------+ | value1 | value2 | +--------+--------+ | NULL | NULL | +--------+--------+ 1 ... Read More