Begin with query language as a majority of programmers use it to work with databases and managing them. Information of course is a valuable resource, even more valuable is the ability to work within it to locate what’s needed at the right time. There’s no place better than the table for data storage.
The language of SQL queries (Structured Query Language)
This is the language of structural queries for interacting with relational databases. It’s widely distributed and is often used to create, update and retrieve information stored in a database. It’s also used to add, delete, modify data or objects.
Knowledge of the SQL basics, ability to apply the query language to search and analyze data is fundamental to the quality assurance or QA’s as well as Back End developers, database programmers and analysts. In SQL simple and readable queries are easy to learn and understand. The syntax of the language is simple and understandable for users not only programmers.
At the heart of the work being performed within relational databases is a strict theory of relations fundamentals. A database is a structure that contains many categories of information and relationships between them. All information is stored in the form of tables so a database consists of several tables between which there are links.
A table is a rectangular grid of cells which can be anything you like or need to create. Each table has its own unique name so as not to get confused. The table consists of records called strings and its field represent a structure. An example of a field can be Name, Address, Phone, Date of Birth, Author, Title, Genre of the book as well as Notes. The field type imposes certain restrictions on the data that is stored in the table consisting of text, numerical and dates. The tables from which the databases are composed represent some relation.
To find the necessary information within a database you must correctly form the SQL query. It is a linear sequence of commands. The requested query extracts the required data, modify it, create tables and even change the structure. The standard query for example “where our customers live” is possible by using the following options so the database will understand it: SELECT City FROM Customers. Searching for Elena’s client phone number will look like this: SELECT Phone FROM Clients WHERE Name = ‘Elena’. FROM indicates the table on which the request is made. WHERE filters the rows and the value of the columns to be printed.
SQL queries are: Keywords; Identifiers for data within the database: tables, columns, operations, functions; expressions for creating search conditions. With databases it’s not only the administrators who create tables but also end users that regularly use database information in their daily work. The syntax of SQL is similar to the natural language (English). This is a powerful and simple programming language for database management that’s also easy to learn.
New knowledge requires practice in order to use it correctly. Do you want to work with databases and SQL queries? Come to the educational IT-center Level Up for a course in SQL database management and we’ll help you to understand the concepts, syntax of this language and teach you how to work with databases.
Our course is a guide to SQL for beginners, it’s intended for beginners with a low level of training in the IT field but with serious career intentions and working with SQL databases. Basic understanding and be a confident PC user with the knowledge in the scope of the school curriculum.