The PHP, MySQL and SQL online test assesses candidates' knowledge of programming in the PHP language, as well as their ability to use MySQL and SQL.
It's an ideal test for pre-employment screening. A good PHP developer, who is working exclusively on an MySQL server database layer, needs to not only solve problems using PHP, but also to write and analyze SQL queries that are used for communication with the database and to use MySQL-specific features to interface efficiently with a database.
This online test requires candidates to solve coding problems in PHP, answer multiple-choice questions about MySQL and write SQL queries that extract, combine, and manipulate data.
Sample Candidate Report
Sample Free Questions
Paginate Users
3min
-
Easy
Easy
-
MCA
MySQL
Pagination
Public
MySQL
MySQL is an open-source relational database management system. It is one of the most widely used databases and is prominent in the popular LAMP stack.
Pagination
Pagination is the process of dividing data into discrete pages. It can be used to reduce the overhead of fetching large quantities of data, and as such, it is important when developing systems that fetch remote data.
Public
Public questions (free account) are common interview questions. They are great for practicing, or if you want to filter candidates using the classic problems.
Consider the following table:
CREATE TABLE users (
id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY,
username VARCHAR(50) NOT NULL
);
The following query is used to paginate the table:
SELECT * FROM users ORDER BY username LIMIT 5 OFFSET 15;
Select all the true statements about this method of pagination.
(Select all acceptable answers.)
Students
3min
-
Easy
Easy
-
CODE
SQL
Aggregation
Public
SQL
SQL is the dominant technology for accessing application data. It is increasingly becoming a performance bottleneck when it comes to scalability. Given its dominance, SQL is a crucial skill for all engineers.
Aggregation
An aggregate function is typically used in database queries to group together multiple rows to form a single value of meaningful data. A good programmer should be skilled at using data aggregation functions when interacting with databases.
Public
Public questions (free account) are common interview questions. They are great for practicing, or if you want to filter candidates using the classic problems.
Given the following data definition, write a query that returns the number of students whose first name is John. String comparisons should be case sensitive.
TABLE students id INTEGER PRIMARY KEY, firstName VARCHAR(30) NOT NULL, lastName VARCHAR(30) NOT NULL
File Owners
10min
-
Easy
Easy
-
CODE
PHP
Language
Public
PHP
PHP is a widely used general-purpose scripting language that is especially well suited for web development.
Language
A programmer should use a language as a tool, always taking advantage of language-specific data types and built-in functions.
Public
Public questions (free account) are common interview questions. They are great for practicing, or if you want to filter candidates using the classic problems.
Implement a groupByOwners function that:
- Accepts an associative array containing the file owner name for each file name.
- Returns an associative array containing an array of file names for each owner name, in any order.
For example, for associative array ["Input.txt" => "Randy", "Code.py" => "Stan", "Output.txt" => "Randy"] the groupByOwners function should return ["Randy" => ["Input.txt", "Output.txt"], "Stan" => ["Code.py"]].
Premium Questions
The premium question library contains our unique, hand-crafted questions. We offer a refund if you find any of them answered online.
Questions
Movies, Index Performance, Poll, Rectangles, Retirees, Authors, Countries, Employee Manager, Merge Stock Index, Cheapest Product, Movies Live, ATM Locations, Department Report, Developers, Delete Orders, Restaurant Menu, Roads, Sales, Student Activities, Transactions, Projects, Youngest Child, Cookie, Chain Link, Crop Ratio, Hobbies, Category Tree, Programmer Teacher, Greeter, Read First Line, Chicken, Numbers to Text, Products, Array Sum, Filter, Paragraph, Last Key, Vectors, Word Count, Log Parser, Date Transform, Needle, Height, Username, View Count, Unique Numbers, Shipping, Segment, Tasks, Ingredients, Autocomplete, Dot Items, JSON Stock, Cargo Concat, Employee Sales, Employee Tree, Bank Branches, Hospital Patients, Menu Items, Ban Users, Array Search, Read Write Execute, SMS MessagesSkills
SQLSQL
SQL is the dominant technology for accessing application data. It is increasingly becoming a performance bottleneck when it comes to scalability. Given its dominance, SQL is a crucial skill for all engineers.
Aggregation
An aggregate function is typically used in database queries to group together multiple rows to form a single value of meaningful data. A good programmer should be skilled at using data aggregation functions when interacting with databases.
Subqueries
Subqueries are commonly used in database interactions, making it important for a programmer to be skilled at writing them.
Indexes
The proper implementation and use of indexes are important for improving the performance of database queries.
Conditions
Conditional statements are a feature of most programming and query languages. They allow the programmer to control what computations are carried out based on a Boolean condition.
Insertion
Even though most database insert queries are simple, a good programmer should know how to handle more complicated situations like batch inserts.
Language
A programmer should use a language as a tool, always taking advantage of language-specific data types and built-in functions.
Joins
A normalized database is normally made up of multiple tables. Joins are, therefore, required to query across multiple tables.
Union
In mathematics, a union typically involves testing if an element exists in two or more sets. This definition also applies as an operator and function in various programming languages. As one of the most common collection operations, alongside intersection, it's an important topic for any candidate to understand.
Constraints
Constraints are used to define rules and relationships. They are applied to a dataset. A constraint may take many forms, such as x ≤ 5 in a programming language and a NOT NULL constraint in a SQL table definition.
Database schema
A database schema defines how data is stored in a database. An SQL database uses a schema to define tables consisting of rows and columns that use fixed data types to store data. Formalizing how data is stored is the first step towards building an application or service.
Bug fixing
Everyone makes mistakes. A good programmer should be able to find and fix a bug in their or someone else's code.
Delete
The delete statement is used to delete records in a table and is one of the four basic CRUD functions (create, read, update, and delete) required for working with any persistent storage.
Update
The UPDATE statement is used to modify the existing records in a table and is one of the most used operations for working with the database.
Views
A database view is a result set that is defined by a stored query, the results of which can can also be queried. As a fundamental and widely used database construct, it's useful for candidates to understand how and when they should be used.
PHP
PHP is a widely used general-purpose scripting language that is especially well suited for web development.
Data structures
Choosing the right data structure to solve a problem can have huge implications on the performance of an application. Knowing when to use a specific data structure is one of the most important skills for a programmer.
Arrays
An array is a container of a fixed number of objects of a similar type. It is a fundamental component of most programming languages.
Iteration
Iteration is the act of repeating a process, or cycling through a collection. Iteration is one of the fundamental flow control tools available to developers.
OOP
Object-oriented programming is a paradigm based on encapsulating logic and data into objects, which may then contain fields and procedures. Many of the most widely used programming languages are based on OOP, making it a very important concept in modern programming.
Exceptions
Exceptions exist in most modern programming languages, making it important for a programmer to understand them and know how to handle them.
Strings
The string data structure is used to represent text. It is one of the most commonly used data structures. Therefore, every programmer should be skilled at string manipulation.
Serialization
Familiarity with data serialization to and from formats such as XML and JSON is important as it is commonly used for interprocess communication
Sorting
Every programmer should be familiar with data-sorting methods, as sorting is very common in data-analysis processes.
Arithmetic
Arithmetic is a fundamental branch of mathematics. An understanding of arithmetic concepts, and their application, is important for every candidate.
Searching
Every programmer should be familiar with data-searching methods, as they are very common in data-analysis processes.
Stream
A stream is a sequence of data elements made available over time. It is particularly useful for tasks that may benefit from being asynchronous, including tasks such as I/O processing or reading from a file, and as such is important for developers to understand.
Algorithmic thinking
When designing and/or analyzing an algorithm or data structure, it is important to consider the performance and structure of an implementation. Algorithmic thinking is one of the key traits of a good programmer, especially one working on complex or performance-critical code.
Performance tuning
The performance of an application or system is important. The responsiveness and scalability of an application are all related to how performant an application is. Each algorithm and query can have a large positive or negative effect on the whole system.
MySQL
MySQL is an open-source relational database management system. It is one of the most widely used databases and is prominent in the popular LAMP stack.
String functions
String functions are used for manipulating, searching and processing strings. As almost all programs use strings, all developers should know how to make use of string functions.
JSON
JSON is an open-standard format that uses human-readable text to transmit data objects consisting of attribute-value pairs. It's the most common data format used for asynchronous browser/server communication.
Window functions
Window functions operate on a set of rows and return a single value for each row from the underlying query. They are often useful since they does not suffer from information loss, unlike group by queries.
Common table expression
Common Table Expressions are used to simplify complex joins and recursive queries. It's a very useful tool for any developer who writes SQL.
Recursion
A good programmer should be familiar with when to use recursive functions, since they can provide elegant solutions for complex problems.
Score Distribution
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