In a .NET project I need to verify if a string is a valid Microsoft SQL Server 2005 parameter identifier.
Example: SELECT * FROM table WHERE column = @parameter
Is there a runtime class method to validate a string for being a parameter, or is there a regular expression that verifies the rules? (see below)
From the documentation on identifiers, parameters should comply to these general identifier rules:
- The first character must be one of the following: * A letter as defined
by the Unicode Standard 3.2. The
Unicode definition of letters includes
Latin characters from a through z,
from A through Z, and also letter
characters from other languages. *
The underscore (_), at sign (@), or
number sign (#).
Certain symbols
at the beginning of an identifier have
special meaning in SQL Server. A
regular identifier that starts with
the at sign always denotes a local
variable or parameter and cannot be
used as the name of any other type of
object. An identifier that starts with
a number sign denotes a temporary
table or procedure. An identifier that
starts with double number signs (##)
denotes a global temporary object.
Although the number sign or double
number sign characters can be used to
begin the names of other types of
objects, we do not recommend this
practice. Some Transact-SQL functions
have names that start with double at
signs (@@). To avoid confusion with
these functions, you should not use
names that start with @@.- Subsequent characters can include the following: * Letters as defined
in the Unicode Standard 3.2. *
Decimal numbers from either Basic
Latin or other national scripts. *
The at sign, dollar sign ($), number
sign, or underscore.- The identifier must not be a Transact-SQL reserved word. SQL Server
reserves both the uppercase and
lowercase versions of reserved words.- Embedded spaces or special characters are not allowed.
- Supplementary characters are not allowed.
When identifiers are used in
Transact-SQL statements, the
identifiers that do not comply with
these rules must be delimited by
double quotation marks or brackets.
Since I want to validate parameters only, identifiers must start with an @ sign, and must not be delimited.
Are you trying to parse SQL from some app, or do you want to run the SQL statement afterwards?
I found this article about creating a function for evaluating regular expressions on TSQL, internally uses VBScript, check it out here
Another link you can find useful, but i think it needs registration, here
Another idea could be handle @parameter as a sysname datatype, don’t know if it fits here
I was stumbling over the Unicode character classes, but once I found out that they are supported in .NET regular expressions, I came up with the following regular expression solving my question:
@[\p{L}{\p{Nd}}$#_][\p{L}{\p{Nd}}@$#_]*This enforces: