relational database and SQL statement-related concepts

Defined

Data Warehouse , which holds the data . is a file system , but also the use of files to save data , but access to data ( increase Delete modify query ) You must use a standard SQL statement to access

A common relational database

*oracle-- large-scale applications, for a fee.

*mysql--A small database, free open source! acquired by Oracle and charged from the 6.x version.

*sqlserver-- Microsoft

*DB2--IBM 's company, the bank's business.

Related concepts

* The server where the database is installed on the computer, create multiple databases in the database server

* Create multiple tables in each database, the table is used to save the data, the table contains the field (column name), the data stored in the field.

* in Java code, a JavaBean object that corresponds to a row of data in the table.

The installation package for the MySQL database has the extension MSI

The common Graphical interface is : Sqlyong navicat

Sql

1. SQL Language is a non-procedural language

*sql:Structured Query Language, structured querying language

* Procedural language: The execution of this statement depends on the previous or previous statement.

* Non-procedural language: There is only one single statement that produces a result.

2. Classification of SQL languages

*ddl(Data Definition Language)

* Data definition language, CREATE DATABASE CREATE TABLE structure

* Create drop

*dml(Data manipulation Language)

* Data manipulation language, add data to modify data Delete data

* Insert Update Delete

*DCL(Data Control Language)

* Data Control Language, stored procedure

* If Else

*DQL(Data Query Language)

* data Query Language, query data

* Select

relational database and SQL statement-related concepts