官术网_书友最值得收藏!

Overview of SQL

Structured Query Language (SQL) is used to manipulate, retrieve, insert, update, and delete data in relational database management system (RDBMS). To make it simpler, SQL tells the database what to do and exactly what it needs. SQL is a standard language that all RDBMS systems such as MySQL, MS Access, MS SQL, Oracle, Postgres, and others use.

Using SQL, the user can access, define and manipulate the data from MySQL. We can leverage SQL modules, libraries, and precompilers to embed with the other languages which help in creating/dropping databases and tables, manage view, stored procedures, function etc. in a database. Using SQL, we can also manage permissions on tables, procedures and different views.

The following are a few important SQL commands that we explain in detail later in the chapter:

  • SELECT: Extracts data from a database
  • UPDATE: Updates data from a database
  • DELETE: Removes existing records from a database
  • INSERT INTO: Add new information into a database
  • CREATE DATABASE: Creates a new database
  • ALTER DATABASE: Modifies or change characteristics of a database
  • DROP DATABASE: Delete a database
  • CREATE TABLE: Creates a new table
  • ALTER TABLE: Modifies or change characteristics of a table
  • DROP TABLE: Deletes a table
  • CREATE INDEX: Creates an index
  • DROP INDEX: Remove an index
主站蜘蛛池模板: 乐平市| 朔州市| 丹江口市| 新民市| 合肥市| 志丹县| 南华县| 报价| 富平县| 措勤县| 大新县| 高青县| 瓦房店市| 和静县| 漳浦县| 中宁县| 枣庄市| 精河县| 巩义市| 交城县| 盐源县| 阿鲁科尔沁旗| 泽州县| 安乡县| 哈巴河县| 花莲市| 新竹市| 阿拉善右旗| 鸡东县| 娄烦县| 虞城县| 舞钢市| 新乡县| 衡南县| 饶平县| 台东市| 裕民县| 宾川县| 治多县| 堆龙德庆县| 海晏县|