MySQL is the most popular relational database management system, MySQL WEB application is the best RDBMS: one (Relational Database Management System relational database management system) applications.
What is a database?
Database (Database) is in accordance with the data structure to organize, store and manage data warehouse.
Each database has one or more different API is used to create, access, manage, search, and copy the saved data.
We also can be in the file, but read and write data in a file relatively slow data storage.
So now we use a relational database management system (RDBMS) to store and manage large amounts of data. The so-called relational database, the database is established on the basis of the relational model, by means of mathematical concepts and methods of collection of algebra to process the data in the database.
Features i.e. relational database management system RDBMS (Relational Database Management System) of:
1 . Data in the form of a table
2 for each behavior of various record name.
3 each as a recording data corresponding to the domain name.
4 a number of rows and columns. the composition forms a
form database 5. several compositions
The term & RDBMS
database: A database is a collection of related tables.
Data: Table are matrix data. In a database table looks like a simple spreadsheet.
Column: one (data element) contain the same type of data, such as a zip code.
Rows: one ( = tuple or record) is a group of related data, such as a user subscription data.
Redundancy: store twice as much data redundancy reduces the performance, but to improve the security of the data.
Primary key: Primary key is unique. A data table can contain only one primary key. You can use the primary key to query the data.
Foreign Key: foreign key for associating the two tables.
Composite key: a composite key (key combination) the index key as a plurality of columns, typically used in the composite index.
Index: using the index can quickly access specific information in a database table. Index value in the database is one or more columns in the table is sorted a configuration. Catalog of books similar.
Referential integrity: the integrity of the relationship is not allowed in reference to the requirements referenced entity does not exist. Integrity is the entity relationship model integrity constraints that must be met, the purpose is to ensure data consistency.
MySQL is a relational database (Relational Database Management System), so-called " relational " may be understood as " table " concept, a relational database table by one or several compositions, a table shown in FIG:
Header (header): the name of each column;
column (col): having the same set of data types;
row (row): Each row is used to describe a record of the specific information;
value (value): specific line information, each value must be the same data type of the column;
key (key): the value of the key is unique in the current column.
MySQL database
MySQL is a relational database management system, developed by the Swedish company MySQL AB, now part of Oracle Corporation. MySQL is a relational database management systems, relational database to store data in separate tables rather than putting all the data in a large warehouse, thus increasing the speed and improved flexibility.
MySQL is open source, so you do not need to pay extra fee.
MySQL support for large databases. You can handle tens of millions of records have a large database.
MySQL data using standard SQL language form.
MySQL can run on multiple systems, and supports multiple languages. These programming languages including C, C ++ , Python, the Java, Perl, PHP, Eiffel, Ruby, and Tcl.
MySQL has good support for PHP, PHP is the most popular Web development language.
MySQL support for large databases, support for data warehouse 50 million records, 32-bit file system table maximum support 4GB, 64 -bit systems support the largest table file is 8TB.
MySQL can be customized using the GPL agreement, you can modify the source code to develop their own system MySQL.