SQL NOT EXISTS Let’s consider we want to select all students that have no grade lower than 9. For this, we can use NOT EXISTS, which negates the logic of the EXISTS operator. Therefore, the NOT EXISTS …

2008年9月15日 · 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 as a …

2021年4月20日 · sql server和mysql的区别主要反映在以下几点： 1.本质区别——存储引擎 SQL服务器的保守的储存模式，与MySQL服务器的开放可拓展的储存模式是不一样的。 在存储引擎方面，SQL提 …

2008年9月18日 · This solution is actually the best one due to how SQL server processes the boolean logic. CASE statements in where clauses are less efficient than boolean cases since if the first check …

2016年7月8日 · I am getting this error while trying to connect to the SQL Server. Microsoft SQL Server Error: 18456 Can anybody tell me what the error code means?

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?

SELECT * FROM table INNER JOIN otherTable ON table.ID = otherTable.FK Is there any difference between the statements in performance or otherwise? Does it differ between different SQL …

How to copy/append data from one table into another table with same schema in SQL Server? Edit: let's say there is a query select * into table1 from table2 where 1=1 which creates table1 wi...

2019年4月5日 · SQL to find the number of distinct values in a column Asked 17 years, 2 months ago Modified 2 years, 8 months ago Viewed 826k times

2020年2月13日 · Beginning with SQL Server Management Studio (SSMS) 18.7, Azure Data Studio is automatically installed alongside SSMS. Source Update: Actually Azure Data Studio is in some way …