sql - Not equal <> != operator on NULL - Stack Overflow
2014年10月9日 · <> is Standard SQL-92; != is its equivalent. Both evaluate for values, which NULL is not -- NULL is a placeholder to say there is the absence of a value. Which is why you …
sql server - MSSQL with SSL: The target principal name is incorrect ...
(provider: SSL Provider, error: 0 - The target principal name is incorrect.) (Microsoft SQL Server, Error: -2146893022) What is striking is that if I select Force Encryption as Yes on Sql Server …
Should I use != or <> for not equal in T-SQL? - Stack Overflow
2009年4月6日 · Yes; Microsoft themselves recommend using <> over != specifically for ANSI compliance, e.g. in Microsoft Press training kit for 70-461 exam, "Querying Microsoft SQL …
mysql - What does SQL Select symbol || mean? - Stack Overflow
2014年4月29日 · sql server: + (infix operator), concat ( vararg function ) Edit: Now Azure SQL also supports ANSI SQL ...
How do I perform an IF...THEN in an SQL SELECT?
2008年9月15日 · 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 …
sql - NOT IN vs NOT EXISTS - Stack Overflow
2007年5月18日 · In order to filter the student records that have a 10 grade in Math, we can use the EXISTS SQL operator, like this: SELECT id, first_name, last_name FROM student …
sql - ORA-00904: invalid identifier - Stack Overflow
2011年5月17日 · sql> Oracle SQL allows us to ignore the case of database object names provided we either create them with names all in upper case, or without using double quotes. If …
How to check for Is not Null And Is not Empty string in SQL server ...
2011年12月28日 · Check the not null condition and empty string in SQL command is use 'is null / not null' and '!='. please try this sample pattern script: SELECT * FROM [Employee] WHERE …
database - 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 avoid the "divide by zero" error in SQL?
2009年5月14日 · I agreed with Mark Sowul's assertion that the scalar function will cause pain. This is a terrible suggestion in T-SQL, don't do it! Scalar Functions are performance …