We can concatenate multiple MySQL rows into one field using GROUP_CONCAT function in mySQL query. There might be situations when you select multiple values from multiple tables and after all the joins you have got a lot of rows than you would like. We can use`GROUP_CONCAT` to obtain the same result with less numbers of rows.
Get the last inserted ID of a MySQL table is a simple query to obtain the primary key of the record you just inserted to the table. Here I have explained the query using PDO as well as Mysqli.
Also, I have abbreviated few points while using PDO or if you are trying to get the last inserted ID of a MySQL table in PHP using other methods.
In some scenario we need to display data in multiple columns in a HTML table where each row from database keeps data for a single column. The data can be text, image or mixture of both. This article will guide you display data in multiple columns from database using PHP.
With help of the following simple query you can find sum of multiple columns values in a row.
In the `marks` table below we have roll number and marks of each student in physics, chemistry and maths. Now we wish to find sum of marks obtained by each student.
You can easily remove duplicate rows in MySQL and keep just one record for each. I have provided two solutions here, one is simple query and second is using subquery to attain the same
If we try to execute a simple MySQL query or any database query that contains reserved word as a table or column name we come across syntax errors.
We have discuss two options to have Defense from syntax error using a reserved word as a table or column name.
Many times we need to retrieve the last record in each group while working with database. Here group is set of those rows which have a identical column value.
You can use a ‘GROUP BY‘ to obtain the result but query with ‘LEFT JOIN‘ performs far better.
In this article we are presented with few methods and tips to prevent SQL Injection attacks in our web application.
In simple term when an application takes user data as an input, there is an opportunity for a malicious user to enter carefully crafted data that causes the input to be interpreted as part of a SQL query instead of data in our application.
SQL Injection is the hacking technique which attempts to pass SQL commands (statements) through a web application for execution by the backend database. If user input is inserted without modification into an SQL query, then the application becomes vulnerable to SQL injection