A trigger is a named database object that is associated with a table, and that activates when a particular event occurs for the table. Some uses for triggers are to perform checks of values to be inserted into a table or to perform calculations on values involved in an update.
A character set is a set of symbols and encodings. A collation is a set of rules for comparing characters in a character set. Let's make the distinction clear with an example of an imaginary character set.
Suppose that we have an alphabet with four letters: A, B, a, b. We give each letter a number: A = 0, B = 1, a = 2, b = 3. The letter A is a symbol, the number 0 is the encoding for A, and the combination of all four letters and their encodings is a character set.
The database structure optimization is very important because if you store large data in in small space then it is save I/O and search time. The following points should be kept in mind when design DB structure.
- Optimizing Data Size
- Optimizing MySQL Data Types
- Optimizing for Many Tables
- Internal Temporary Table Use in MySQL
Optimizing Data Size
The following features have been added to MySQL 8.0:
Data dictionary:MySQL now incorporates a transactional data dictionary that stores information about database objects
Atomic data definition statements (Atomic DDL):An atomic DDL statement combines the data dictionary updates, storage engine operations, and binary log writes associated with a DDL operation into a single, atomic transaction.
How to use PHP and MySql in Web Development
Step 1: If we need to interact with database the first step is to connect with database. Here is object oriented style to connect with database.
$conn = new mysqli("localhost", "my_user", "my_password", "db_name");
Step 2: After sucessfly established connection with database we can perform CURD operation on database. Here are the function that are commonly
used to perform CURD :
Performs a query on the database
$result = $conn->query($sql_query)
Determine number of rows result set
The traits is very important concept that help the developer to implement the reuse and optimization of the code . Before giving the exact defination of trais let me share advantage traits
The View module is very important and commanly used for almost all type that why Drupal comunity added this module as core module in Drupal 8 , Here are the important points you should know about this module.
What is contextual filter in view module
You can configure a view so that it is filtered dynamically, depending on the context. For example, you could use a contextual filter to add a block that contains related content or that presents a list of articles by the same author.
The interface, Abstract and inheritance are the very important concept of oops that will help to design the application perfectly. First let discss the difference between abstract class and interface then I will explain how to implemennt.
Namespaces : The namespaces is basically the name of folder/directory[physical or virtual] in which you put all code that belong to specific group. For example you are wrting code for image gallary then it is better to put all code in one folder with name "image_gallery" so that when you create other image gallery then you can simply put in other folder so but you use same class name and file name.The other benefit is that if your code integrated with other code then it do not create any problem.