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Simple .NET/ASP.NET PDF document editor web control SDKF# is a multiparadigm language, and in this chapter you looked at the core language constructs used for functional programming. In the next chapter, you ll look at how to use F# for imperative programming, that is, how to use mutable state, raise and handle exceptions, and perform I/O. free barcode generator for excel, microsoft barcode control excel 2010, barcode in excel 2003, generate barcode in excel 2010, how to install barcode font in excel 2010, vba code for barcode in excel, barcode generator in excel 2007 free download, excel barcode schriftart, barcode in excel 2017, 2d barcode excel 2013,The next security topic we ll discuss is encryption. Simply put, encryption is the process of keeping sensitive information safe and sound. More formally, encryption is used to ensure that message data (such as a social security number, bank account ID, or user password) cannot be altered and/or understood by evildoers. From a high level, encryption addresses the following security issues: Tuning SQL written in PL/SQL is quite easy. For example, starting a SQL trace for the PL/SQL code is trivial. For JDBC, you have to have a mechanism to indicate whether or not the code should be traced. Besides, for fixing the code, you need to recompile the Java classes and redeploy them on all your middle-tier machines. In the case of PL/SQL, once you recompile it, the changes are immediately available for every user. n 3 you saw some of the simple but powerful data types and language constructs that make up F# functional programming The functional programming paradigm is strongly associated with programming without side effects, called pure functional programming In this paradigm, programs compute the result of a mathematical expression and do not cause any side effects, except perhaps reporting the result of the computation The formulae used in spreadsheets are often pure, as is the core of functional programming languages such as Haskell F# is not, however, a pure functional language; for example, you can write programs that mutate data, perform I/O communications, start threads, and raise exceptions Furthermore, the F# type system doesn t enforce a strict distinction between expressions that perform these actions and expressions that don t Programming with side effects is called imperative programming. If you want to add another line of code after an insert statement in PL/SQL (say, to log or audit the insert), it is easy. If you were using PreparedStatement, though, you would have to prepare, bind, and execute another statement. Integrity: If the message has been intercepted and modified during transport, the receiver should detect it. You ensure this using a cryptographic hash code. Confidentiality: The message data shouldn t be directly readable if it s intercepted by prying eyes. You accomplish this using encryption and decryption techniques. Authentication: The receiver of the message should be able to ensure the message came from the anticipated sender. You achieve this using digital signatures. Although each flavor of encryption addresses a specific need (integrity, confidentially, and authentication), the programming model used to work with hash codes, encryption services, and digital signatures is more or less identical. Given this fact, we ll limit this part of our security overview to the role of hash codes. In this chapter, we look more closely at a number of constructs related to imperative programming We describe how to use loops, mutable data, arrays, and some common input/output techniques If your primary programming experience has been with an imperative language such as C, C#, or Java, you will initially find yourself using imperative constructs fairly frequently in F# However, over time F# programmers generally learn how to perform many routine programming tasks within the side-effect-free subset of the language F# programmers tend to use side effects in the following situations: When scripting and prototyping using F# Interactive When working with . All related PL/SQL code in a PL/SQL unit involves only one server round-trip. For example, invoking a PL/SQL procedure using a CallableStatement would involve one round-trip no matter how many SQL statements are executed in the PL/SQL procedure. Note that to process any result sets returned, you will still make multiple round-trips based on your fetch size this is true regardless of the statement class you use in JDBC. If you use PreparedStatement, however, the number of round-trips would be as many as the number of statements you need to invoke (plus any others you need to make to process your result sets). So far, we ve looked at various reasons to use PL/SQL. Let s now look at things that you should watch out for while writing PL/SQL code.
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