如何自学SQL？ - 知乎
sql不能像编程语言一样，使用变量、条件逻辑、循环结构等对过程进行定义，以获得想要的结果。sql直来直去，只要定义必要的输入输出，没有对过程的控制。 了解sql的大致情况后，我们再 …
Should I use != or <> for not equal in T-SQL? - Stack Overflow
Mar 26, 2018 · Yes; Microsoft themselves recommend using <> over != specifically for ANSI compliance, e.g. in Microsoft Press training kit for 70-461 exam, "Querying Microsoft SQL …
sql是什么，通俗的说，太专业听不懂？ - 知乎
sql是一门语言，就和我们平时说话一样，有主谓宾的层次结构，同样sql也有自己的一套语法规则。 记住这些语法规则就可以与数据库打交道了，不管是查询，新增，更新，删除数据，都可 …
如何学习 SQL 语言？ - 知乎
SQL 真的不难，用 20 个小时来学习完全足够了。 「1」刷题前之前了解下 SQL 是什么： 结构化查询语言(Structured Query Language)简称SQL，是一种数据库查询和程序设计语言，用于存 …
How do I perform an IF...THEN in an SQL SELECT?
Sep 15, 2008 · The CASE expression cannot be used to control the flow of execution of Transact-SQL statements, statement blocks, user-defined functions, and stored procedures. If your …
SQL SELECT WHERE field contains words - Stack Overflow
May 31, 2023 · If your SQL dialect supports CHARINDEX, it's a lot easier to use it instead: SELECT * FROM MyTable WHERE CHARINDEX('word1', Column1) > 0 AND …
Simple way to transpose columns and rows in SQL?
Figure out another method for the transposition of rows and columns that doesn't require an actual SQL table. Figure out an appropriate method of allowing the SQL account used by my …
How to select unique records by SQL - Stack Overflow
When I perform SELECT * FROM table I got results like below: 1 item1 data1 2 item1 data2 3 item2 data3 4 item3 data4 As you can see, there are dup records from column2 (item1 are …
How to set variable from a SQL query? - Stack Overflow
To ASSIGN variables using a SQL select the best practice is as shown below->DECLARE co_id INT ; ->DECLARE sname VARCHAR(10) ; ->SELECT course_id INTO co_id FROM …
How to insert a line break in a SQL Server VARCHAR/NVARCHAR …
Jul 10, 2013 · Following a Google.... Taking the code from the website: CREATE TABLE CRLF ( col1 VARCHAR(1000) ) INSERT CRLF SELECT 'The quick brown@' INSERT CRLF SELECT …