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- 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
- Should I use != or lt; gt; 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 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
- 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
- How do I perform an IF. . . THEN in an SQL SELECT?
The CASE statement is the closest to IF in SQL and is supported on all versions of SQL Server
- SQL: IF clause within WHERE clause - Stack Overflow
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 '%' + @
- SQL to find the number of distinct values in a column
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
- sql - What is the difference between JOIN and INNER JOIN . . . - Stack . . .
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?
- sql - Concatenate text from multiple rows into a single text string . . .
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?
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