如何自学SQL？ - 知乎
SQL是所有数据库查询的语言，sql由于本身结构化的特点，非常容易入手。 针对不同的数据库，如hivesql、mysql、sqlserver、oracle等，sql语法会有所不同，但是总体上大同小异，只是细微 …
如何学习 SQL 语言？ - 知乎
SQL系列： 6000赞实战题目分享：如何学习 SQL 语言？ 刷题！ ！！ 新整理的 SQL 面试题： 面试数据分析会遇到的SQL题~不定时更新~ PYTHON系列： 做到这些就可以精通Python：编程零 …
sql是什么，通俗的说，太专业听不懂？ - 知乎
SQL是一种用于处理数据的语言，就像我们说的汉语、英语一样，有特定的语法结构，让我们灵活地处理数据。 SQL并不难学，首先得理解 S Q L 三个字母分别代表什么。 Structured Query …
Should I use != or <> for not equal in T-SQL? - Stack Overflow
I have seen SQL that uses both != and <> for not equal. What is the preferred syntax and why? I like !=, because <> reminds me of Visual Basic.
通俗易懂的学会：SQL窗口函数 - 知乎
Oct 12, 2025 · 视频《最通俗易懂的学会SQL窗口函数》 SQL从入门到进阶 (视频+社群) 3.聚合函数作为窗口函数 聚和窗口函数和上面提到的专用窗口函数用法完全相同，只需要把聚合函数写在 …
sql - Not equal <> != operator on NULL - Stack Overflow
Apr 14, 2011 · In SQL, anything you evaluate / compute with NULL results into UNKNOWN This is why SELECT * FROM MyTable WHERE MyColumn != NULL or SELECT * FROM MyTable WHERE …
sql - Concatenate text from multiple rows into a single text string ...
Consider a database table holding names, with three rows: Peter Paul Mary Is there an easy way to turn this into a single string of Peter, Paul, Mary?
SQL - STDEVP or STDEV and how to use it? - Stack Overflow
SQL - STDEVP or STDEV and how to use it? Asked 12 years, 11 months ago Modified 3 years, 3 months ago Viewed 129k times
How do I perform an IF...THEN in an SQL SELECT?
Sep 15, 2008 · Looks like an old question, however if I understood your question and thought correctly, you want to implement the if/else conditional statement in SQL. Both are calculated …
How to see query history in SQL Server Management Studio
Is the query history stored in some log files? If yes, can you tell me how to find their location? If not, can you give me any advice on how to see it?
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