The Wiert Corner - irregular stream of stuff: jpluimers

Normally you would not want to use a reserved word as an identifier. But sometimes it can be very convenient, for instance for a code generator that wraps remoting calls or does ORM.

Both Delphi and C# have an escape for this:

• & prefix for Delphi.
• @ prefix for C#.
• [] embedding for VB.NET.
• “” embedding in many SQL syntaxes.

The prefixes are to tell the compiler knows you really know what you are doing, and are using a reserved word as an identifier.

The cool thing: in the Run Time Type Information (Delphi) or Reflection (C# and VB.NET) you will see the names without the prefix.

Some examples from StackOverflow:

& prefix for Delphi

private &string: Integer;

Kenny Cason answered delphi – Is it possible to use reserved words for field names? – Stack Overflow.

@ prefix for C#

private long @string;

Jon Skeet answered Use the long reserved word as a variable name in C# – Stack Overflow.

[] embedding for VB.NET

Private [string] As Integer;

Tobias Wittenburg asked vb.net – Reserved Keyword in Enumeration in C# – Stack Overflow.

The VB.NET way also works in Microsoft SQL Server and Microsoft Access.

“” embedding in many SQL syntaxes

Examples:

• escaping – How do I escape reserved words used as column names? MySQL/Create Table – Stack Overflow.
• How do I escape a reserved word in oracle – Stack Overflow.
• sql – Using Reserved Word TimeStamp as a field name (Firebird 2.5) – Stack Overflow.

Exception: Microsoft SQL Server and Microsoft Access use [] embedding.

• Creating table names that are reserved words/keywords in MS SQL Server – Stack Overflow.
• ms access – [] brackets in sql statements – Stack Overflow.

Note:

Some SQL implementations uses the embedding not only to allow for reserved words, but also to allow embedding spaces in identifiers.

Delphi, C# and VB.NET cannot do that, so be aware of that when performing ORM work.

–jeroen