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What does <> (angle brackets) mean in MS-SQL Server?
Nov 8, 2013 · What does <> (angle brackets) mean in MS-SQL Server? Asked 11 years, 8 months ago Modified 3 years, 11 months ago Viewed 80k times
sql - Not equal <> != operator on NULL - Stack Overflow
Apr 14, 2011 · 11 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 MyColumn <> NULL gives you 0 results. To provide a check for NULL values, isNull function is provided. Moreover, you can use the IS operator as you used in the third query.
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 Language,简写为SQL,意思是结构化查询语言。也就是说SQL是用来查询数据用的,通过代码指令来实现个性化的数据抽取 ...
What does the "@" symbol do in SQL? - Stack Overflow
The @CustID means it's a parameter that you will supply a value for later in your code. This is the best way of protecting against SQL injection. Create your query using parameters, rather than concatenating strings and variables. The database engine puts the parameter value into where the placeholder is, and there is zero chance for SQL injection.
SQL: IF clause within WHERE clause - Stack Overflow
Sep 18, 2008 · Is it possible to use an IF clause within a WHERE clause in MS SQL? Example: WHERE IF IsNumeric(@OrderNumber) = 1 OrderNumber = @OrderNumber ELSE OrderNumber LIKE '%' + @
Should I use != or <> for not equal in T-SQL? - Stack Overflow
Apr 6, 2009 · Yes; Microsoft themselves recommend using <> over != specifically for ANSI compliance, e.g. in Microsoft Press training kit for 70-461 exam, "Querying Microsoft SQL Server", they say "As an example of when to choose the standard form, T-SQL supports two “not equal to” operators: <> and !=. The former is standard and the latter is not.
sql - NOT IN vs NOT EXISTS - Stack Overflow
Which of these queries is the faster? NOT EXISTS: SELECT ProductID, ProductName FROM Northwind..Products p WHERE NOT EXISTS ( SELECT 1 FROM Northwind..[Order Details] od WHERE p.
SQL Server : Arithmetic overflow error converting expression to …
I'm getting this error msg 8115, level 16, state 2, line 18 Arithmetic overflow error converting expression to data type int. with this SQL query DECLARE @year ...
IN vs OR in the SQL WHERE clause - Stack Overflow
Jun 19, 2010 · When dealing with big databases, which performs better: IN or OR in the SQL WHERE clause? Is there any difference about the way they are executed?
SQL - 'DISTINCT' based on only some columns? - Stack Overflow
Jul 23, 2011 · I have a database with two tables. One of the tables contains users, the other contains addresses for those users. Each user may have several addresses (though each address is tied to only one user...