As you know laravel is very popular php framework in today. So every point will be require for database related and that important. In this post i would like to share with you how to use subquery with whereIn and whereNotIn clause from scratch.
We may sometimes require to use select query with where in or where not in clause. we can simply make query using MySQL. But we don't know how to use it on laravel query builder. However, In this example we will learn how to convert mysql query into laravel query builder of wherein with subquery. This example is from scratch, so i will give you first m.....
In this post we are going to learn how to get last single record from MySQl database table using Codeigniter database library.
We sometime require to get only single row result in our Codeigniter application. In this post you can see how to get whole last record using Codeigniter db query. Few day ago i posted <a href="http://itsolutionstuff.com/post/how-to-get-last-inserted-id-in-codeigniterexample.html" target="_blank">"How to get last inserted id in Codeigniter?"</a>, in that post we can simply get last inserted id from Codeigniter db query.
In this database query i used order_by(), limit.....
Sometimes, we require to manage to take single column for multiple integer ids, for example if we have "posts" table and require to set multiple tags on each post, so at that time we can take just single column and store selected tags ids. this way will use less memory. It is simple to store data into row, but as you think how we can search or find specific tag id data from comma separated column value using laravel query builder.
However, It is possible using <strong class="path">"find_in_set()"</strong> of MySql predefine function, We can use find_in_set() using whereRow() of laravel query .....
Sometimes we require to get filenames from path of table column in MySQL. If you are working on PHP then you can simply use basename() pre-define function of code PHP, But in MySQL you can't use basename() in select query. This mysql function you can use in code PHP, PHP framework like laravel, codeigniter etc.
However, you can get simply filename or image name from path using SUBSTRING_INDEX() of MySQL. You can extract filename from path using substring_index(), substring_index() take three argument, first for column name, second for split string chat, and third get last element from split. .....
Node.js is very popular in Todays for make chat system, real-time notification, real-time developing etc.
So, Today, I am going to give you very simple example of How to use MySQL Query in Node JS. If you use node.js then you can see how it is work and there are several driver for different task like redis, socket io, express etc.
But Node.js have a driver for MySQL that way we can easily connect with database and you can use select, insert, update and delete sql query.
So, in this example i going to give from scratch so if you are beginner and you haven't installed nodejs on your server th.....
We may sometimes require to get few days ago records from table like last 2 days, last 3 days, last 10 days or last 15 days etc. Most of developer choose other logic but we can easily get using mysql query(using CURDATE and INTERVAL).
In this example mysql query i have one table "elements" and columns are id, title, description, created_at(timestamps) and update_at, Now we will get all records of last 2 days.so you can fetch fields value using CURDATE and INTERVAL of mysql. In following example you can see how to select data of last two days.
SELECT * FROM `elem.....
Sometimes we may require to get only last record of table in our project, we can get several way. We can fetch last record of database table using latest() or orderBy(). In bellow example you can see how i get then last record of table.
I have "items" table and i want to get last record of "items" table. In first example i use latest() with first() because latest() will fetch only latest record according to created_at then first() will get only single record:
<strong>Using latest() belong to created_at field:</strong>
<pre class="prettyprint lang-php">
$last = DB::table('items')->latest()->f.....
If you require to get all the records of current year using mysql query. for example you have one table "items" and columns are id, title, description, created_at and update_at, Now you want to get all records of this year. so you can fetch fields value using DATE_SUB and INTERVAL of mysql. In following example you can see how to select data of current year.
SELECT * FROM items WHERE created_at > DATE_SUB(NOW(), INTERVAL 1 YEAR);
Sometimes, we require to get age from birthdate using mysql select query, we can do it in programming like php,.net and etc framework but if we can do it using mysql query. In bellow example mysql query you can learn how to get age from date field. We can get age value from using mysql DATEDIFF(). So, let's see bellow query.
(DATEDIFF(CURRENT_DATE, STR_TO_DATE(born_date, '%Y-%m-%d'))/365) as age
This is more one post on mysql query, I don't remember exactly time but i had need to change name of foreign key constraint column field. We can rename field name easily if we didn't set foreign key constraint. But if you set foreign key constraint then you can't rename easily. I had rename directly from my phpmyadmin without mysql query but i found bellow error:
#1025 - Error on rename of './learn/#sql-46c_246' to './learn/my_table' (errno: 150)
But i found the solution of mysql rename foreign key constraint using mysql query, First we have to drop the foreign key,.....