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所在平台: Udemy |
课程主页: https://www.udemy.com/course/sql-structured-query-language-basics/
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课程名称：SQL（结构化查询语言）基础 课程概述：SQL，即结构化查询语言，是一种用于管理和操作关系数据库的数据的标准编程语言。它允许用户通过查询、插入、更新和删除数据与数据库互动。SQL被所有数据库管理系统使用，如MySQL、PostgreSQL、SQL Server和Oracle等。在本课程中，您将学习SQL的核心概念，掌握如何使用SQL存储、读取和处理数据。您将学习如何使用基本的SQL命令（如SELECT、INSERT、UPDATE、DELETE和JOIN）来检索、操作和管理关系数据库中的数据。 课程内容大纲： 1. 数据库与SQL简介 - 什么是数据库？理解数据库的功能和用途。 - 什么是SQL？SQL在与数据库交互中的作用。 - 理解关系数据库的概念，如表、行、列和键。 2. 基本SQL命令 - SELECT语句：如何从表中检索数据。 - WHERE子句：基于条件过滤数据。 - ORDER BY：按升序或降序排列数据。 - LIMIT：限制返回的行数。 3. 数据的插入、更新和删除 - INSERT INTO：向表添加新记录。 - UPDATE：修改现有记录。 - DELETE：从表中删除记录。 4. 处理多个表 - JOINs：结合来自多个表的数据（INNER JOIN、LEFT JOIN、RIGHT JOIN等）。 - GROUP BY：根据特定列对数据进行分组，通常与聚合函数一起使用。 - HAVING：过滤分组后的数据（类似于WHERE，但适用于聚合结果）。 5. 聚合函数 - 使用COUNT()、SUM()、AVG()、MIN()和MAX()等函数对数据进行计算。 6. 数据类型和约束 - 理解常见数据类型（如INT、VARCHAR、DATE）。 - PRIMARY KEY：确保每条记录的唯一性。 - FOREIGN KEY：强制表之间的关系。 - NOT NULL：确保列不能包含空值。 7. 创建和修改表 - CREATE TABLE：在数据库中创建新表。 - ALTER TABLE：修改现有表的结构（例如，添加新列）。 - DROP TABLE：从数据库中删除表。 课程结束时，您将对结构化查询语言（SQL）有出色的理解，能够编写简单的查询以检索和操作关系数据库中的数据，并理解如何设计和修改数据库结构。
SQL or the Structured Query Language is a standard programming language used to manage and manipulate data in relational databases. It allows users to interact with databases by querying, inserting, updating, and deleting data. SQL is used by all database management systems like MySQL, PostgreSQL, SQL Server and Oracle etc.In this course you will learn core concepts of SQL or the Structured Query Language. You will learn how to use SQL to Store, Read and Manipulate data.Learn how to retrieve, manipulate, and manage data in relational databases using essential SQL commands like SELECT, INSERT, UPDATE, DELETE, and JOIN.Here's a breakdown of what you'd typically learn:1. Introduction to Databases and SQLWhat is a database? Understanding what databases are and why they are used.What is SQL? The role of SQL in interacting with databases.Relational database concepts like tables, rows, columns, and keys.2. Basic SQL CommandsSELECT Statement: How to retrieve data from a table.WHERE Clause: Filtering data based on conditions.ORDER BY: Sorting data in ascending or descending order.LIMIT: Restricting the number of rows returned.3. Inserting, Updating, and Deleting DataINSERT INTO: Adding new records to a table.UPDATE: Modifying existing records.DELETE: Removing records from a table.4. Working with Multiple TablesJOINs: Combining data from multiple tables (INNER JOIN, LEFT JOIN, RIGHT JOIN, etc.).GROUP BY: Grouping data based on certain columns, often with aggregation.HAVING: Filtering grouped data (similar to WHERE, but for aggregated results).5. Aggregate FunctionsUsing functions like COUNT(), SUM(), AVG(), MIN(), and MAX() to perform calculations on data.6. Data Types and ConstraintsUnderstanding common data types (e.g., INT, VARCHAR, DATE).PRIMARY KEY: Ensuring each record is unique.FOREIGN KEY: Enforcing relationships between tables.NOT NULL: Ensuring that a column cannot contain null values.7. Creating and Modifying TablesCREATE TABLE: Creating new tables in a database.ALTER TABLE: Modifying the structure of an existing table (e.g., adding new columns).DROP TABLE: Deleting a table from the database.By the end of this course you will have an excellent understanding of the SQL i.e. the Structured Query LanguageYou should be able to write simple queries to retrieve and manipulate data in relational databases, as well as understand how to design and modify database structures.
