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所在平台: Udemy |
课程主页: https://www.udemy.com/course/sub-query-magic-write-t-sql-subqueries-using-sql-server/
课程评论：没有评论
**课程名称：EssentialSQL: Subquery Magic - Master SQL Sub Queries** **课程概述：** 本课程将带您深入了解 SQL 子查询（Subqueries）的核心概念，并教授如何在 MySQL、PostgreSQL 或 MS SQL Server 中有效地运用它们。您将学习不同类型的子查询，包括相关子查询（Correlated Subqueries）和非相关子查询（Uncorrelated Subqueries），并掌握如何利用它们解决复杂的数据库问题。此外，课程还将涵盖使用子查询时的常见陷阱以及如何优化子查询的性能，使您的 SQL 查询更加高效。 **通过本课程，您将能够：** * **理解子查询：** 掌握子查询的基本原理和作用。 * **识别子查询：** 能够准确地在 SQL 语句中找出子查询。 * **提升查询健壮性：** 利用 `SELECT` 语句中的子查询，减少对硬编码值的依赖，使查询更加灵活和健壮。 * **运用派生表：** 学习使用 `FROM` 子句中的子查询（也称为派生表），克服 SQL 中的一些限制。 * **在 `WHERE` 子句中使用子查询：** 掌握与 `EXISTS` 和 `IN` 配合使用子查询的方法。 * **结合聚合函数：** 将子查询与 `SUM`、`MAX` 等聚合函数结合，并在 `GROUP BY` 和 `HAVING` 子句中使用，实现更强大的数据分析。 * **编写相关子查询：** 学习编写相关子查询，使其与外部查询协同工作，提高查询的灵活性和稳健性。 **课程目标：** 本课程旨在帮助您： * **获得知识：** 快速掌握子查询的使用技巧，将您的 SQL 水平提升到新高度。 * **建立信心：** 对学习 SQL 子查询的方向充满信心。 * **实现成就感：** 掌握大多数人难以企及的 SQL 技能，获得成就感。 * **享受学习：** 真正地享受学习 SQL 子查询的乐趣。 完成本课程后，您将对子查询有深刻的理解，克服对子查询的恐惧，并能够编写相关子查询，使您的 SQL 语句更加强大和可靠。
In this course, you will learn the fundamentals of subqueries and how to use them effectively in your MySql, PostgreSQL, or MS SQL Server SQL statements. You will learn about different types of subqueries, including correlated and uncorrelated subqueries, and how to use them to solve complex problems. You will also learn about common pitfalls to avoid when working with subqueries, and how to optimize their performance in your queries.By the end of this course, you will have a solid understanding of how to use subqueries in your SQL statements, and be able to apply this knowledge to a wide range of real-world scenarios.In this Course you will Learn to:Know and understand subqueries.Identify subqueries in SQL.Use subqueries in your select statement to make your queries more robust and less reliant on hard coded values.Harness the power of derived tables to work around SQL limitations. Derived tables are also known as subqueries in the FROM clause.Use subqueries in the WHERE clause with EXISTS and INUse subqueries with SUM, MAX and other Aggregate functions in GROUP BY and HAVING.Write correlated subqueries so that your subquery is able work with the outer query to become more flexible and robust.Nothing is worse thanBeing excited to learn something new but not knowing where to start.Wasting time learning the wrong features.Being overwhelmed with options and not know which to use.Imagine Having...Knowledge - Knowing how to quickly use subqueries to take your SQL to the next level.Confidence - Feeling good that you're on the right track.Accomplishment - Having a sense of accomplishment that you've learned something most cannot.Fun - Actually having fun learning SQL subqueries!By the time you've completed this SQL course you'll have an appreciation of subqueries, overcome your fear, and able to write correlated queries to make your SQL more robust.
