MySQL Book Pdf Free Download
It is an application which is a storage of collection of data. For creating, accessing, searching and replicating data, each database has distinct APIs. Files on system files and large hash tables in memory or other types of data stores can also be used. But in these types of systems data fetching and writing is not that easy.
Relational Database Managements Systems (RDBMS):
Relational Database Managements Systems (RDBMS) are used now-a-days for storing and managing huge amount of data. Since all the data is stored in different tables and foreign keys are used to establish relations.
Relational Database Management System (RDBMS) has following features:
- Implementations of database using tables, columns and indexes.
- Referential Integrity between rows and columns is guaranteed.
- Automatic updates of indexes.
- Interpretation of a SQL query with a combination of information from different tables.
It is a collection of related data in tables.
It is a matrix of data which looks like spreadsheets.
Column is a collection of the same type and kind of data in a database.
Example, Postcode column.
Row (tuple, record or entry) is a group of related data. Example, data of one subscription.
For making the system faster redundantly, storing it twice.
- Primary keys:
A unique key, whose value cannot occur twice in a table. It can be used to find only one row.
- Compound key:
Compound key also known as composite key consists of many columns as one columns is not unique and distinct.
- Foreign key:
The linking key between two tables is called foreign key.
- Referential Integrity:
It makes sure that the foreign key value is always pointing to an existing row.
As we have an index at the back of the book, same is the case in index of a database.
For many small and large businesses SQL is an easy to use RDBMS. A Swedish company MySQL AB, developed, marketed and supported SQL. It is popular due to its features some of them are listed below:
- MySQL, is free to use as it is released under an open source licensed. So anyone can use it without paying for it.
- It can also be used with large data sets, as it works well and fast with these also.
- A well known standard form of SQL data language is used by MySQL.
- PHP is a very appreciated and popular web development language, MySQL is very friendly with PHP.
- It works well with other operating systems having different languages as PHP, Java, PERL, C, C++, etc.
- A large subset functionality of expensive and powerful data packages are handle by MySQL, which is a very powerful program.
- The customizable feature of MySQL allows you to modify the software according to your own requirements as GPL license allowed programmers to do so.