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.
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.
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.
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 '%' + @
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 implementations?
Due to precedence of SQL statements it will be the same. however, due to data types if using 100 you can still get the result rounded to 0 decimals you desire for the % where as if you put it after the division operation you would have to make sure that you cast to a data type that can handle the decimal places otherwise you will end up with ...
