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] …
Should I use != or <> for not equal in T-SQL? - Stack Overflow
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 …
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 …
SQL WITH clause example - Stack Overflow
2012年9月23日 · 352 The SQL WITH clause was introduced by Oracle in the Oracle 9i release 2 database. The SQL WITH clause allows you to give a sub-query block a name (a process also …
SQL: IF clause within WHERE clause - Stack Overflow
2008年9月18日 · Is it possible to use an IF clause within a WHERE clause in MS SQL? Example: WHERE IF IsNumeric(@OrderNumber) = 1 OrderNumber = @OrderNumber ELSE …
How do I perform an IF...THEN in an SQL SELECT?
2008年9月15日 · The CASE statement is the closest to IF in SQL and is supported on all versions of SQL Server. SELECT CAST( CASE WHEN Obsolete = 'N' or InStock = 'Y' THEN 1 ELSE 0 …
SQL Server® 2016, 2017, 2019 and 2022 Express full download
2017年1月25日 · All previous version of SQL Server Express were available in both web and full downloads. But I cannot find full download of SQL Server® 2016 Express. Does it exist? …
sql - Delete duplicate rows keeping the first row - Stack Overflow
10 To delete the duplicate rows from the table in SQL Server, you follow these steps: Find duplicate rows using GROUP BY clause or ROW_NUMBER () function. Use DELETE …
sql - Find all tables containing column with specified name - Stack ...
In MS SQL Server Database, use this query to get the tables and respective column names that contains the input text: SELECT t.name AS tableName, c.name AS columnName
sql - What is the difference between JOIN and INNER JOIN
per the ANSI SQL 92 specification, they are identical: "3) If a <qualified join> is specified and a <join type> is not specified, then INNER is implicit."