In Ruby it's possible to use the strings without the need to escape the double quote in the string, like Q/Some my string with "double quotes"/
Is it possible with C# to use a string without a need to escape double quotes?
For a good reason I need to write inline SQL and it's very annoying to escape double quotes every time I put SQL query from DB console to C# code.
I know it's possible to use \" or "" as one double quote. But is it possible to avoid the need to escape the double quotes?
No, basically. You have the choice of "foo \" bar" or #"foo "" bar", both of which you have mentioned. However, frankly I rarely find " necessary in SQL; you have ' for literal strings and [ / ] for object/column names - of course, this might just be because I usually use SQL Server.
The only alternative that doesn't involve any escaping is to move the SQL to an external resource file, maybe a text file. That, though, is probably more painful than just using "".
No, this is not possible in C#. You could write your SQL in a separate file and then read it from there.
For a good reason I need to write inline SQL and it's very annoying to
escape double quotes every time I put SQL query from DB console to C#
code.
If you are writing a Inline Sql Query you don't need to worry about quotes if you passed the values via SqlParameters. This way you won't see the annoying double quotes every where and even your query will safe from Sql Injection
Related
I've a problem where I want to replace some specific single quotes with double quotes inside a SQL string but not all singles quotes in that string.
EXEC procedureName 'param'eter1', 'parameter2'
In above example I just want to replace the singles quotes inside the 'param'eter1' but the singles quotes in start and end of the parameter to remain same.
Using below command replace all singles quotes in the string and it looks like this ''param''eter1'' which is not correct.
sometext.Replace("'", "''")
I want it to look like this:
EXEC procedureName 'param''eter1', 'parameter2'
Also please note that I am already aware that using SqlParameter is a better solution to handle the single quotes in SQL parameters but due to the restrictions in the project environment I am unable to implement that.
Update:
Changing the individual parameters before using them to construct the full statement is not an option for me as I don't have access to that code. My project works like a data layer where it received SQL strings from other applications to process.
This is a very bad idea. The SQL syntax requires you to escape single quotes in literals exactly because it can otherwise not tell whether the single quote is meant to represent a single quote or meant to terminate the string literal.
Consider the following example:
EXEC procedureName 'param ', ' eter1', 'parameter2'
How would you know whether this is meant to have three parameters for the procedure call or only two? And even if you knew that this specific procedure takes two parameters, you couldn't decide whether the middle part belongs to the first or second parameter.
If the system constructs sql statements from user input without dealing with single quotes before the full statement is constructed, this can be used very easily to attack the system via an sql injection.
you can do like this
var aStringBuilder = new StringBuilder(theString);
aStringBuilder.Remove(3, 2); // just find a position of single quotes
aStringBuilder.Insert(3, "/""); // replace that position with " quotes using loop
theString = aStringBuilder.ToString();
Basically, I have an application that needs to support both Lucene.NET and Amazon CloudSearch.
So, I can't re-write the queries, I need to use the standard queries from lucene, and use the .ToString() on the query to get the syntax.
The issue is that in Lucene.NET (I don't know if this is the same in the java version), the .ToString() method return the raw string without the escape characters.
Therefore, things like:
(title:blah:blah summary:"lala:la")
should be
(title:blah\:blah summary:"lala\:la")
What I need is a regex that will add the escapes.
Is this possible? and if so, what would it look like.
Some additional possible variances:
(title:"this is a search:term")
(field5:"this is a title:term")
Based on comments and edits, it seems that you want any query string to be able to be correctly escaped by the regex, and any given lucene query to be accurately represented by the resulting string.
That ain't gonna happen.
Lucene query syntax is not capable of expressing all lucene queries. In fact, the string you get from Query.toString() often can't even be parsed by the QueryParser, nevermind being an accurate reconstruction of the query.
The long and short of it: You are going about this the wrong way. Query.ToString() is not designed to serialize the query, and it's goal is not to create a parsable string query. It's mainly for debugging and such. If you keep attempting to use it this way, this tomfoolery of trying to use a regex to escape ambiguous query syntax will likely just be the start of your troubles.
This question provides another example of this.
You can use this regex to escape the colon : at strategic points of the string
(?<!title|summary):
Then escape the captured colon :
Explanation
Look behind ?<! for any colon that is not followed by title or summary, then match the colon :
See Demo
input
(title:blah:blah summary:"lala:la")
Output
(title:blah\:blah summary:"lala\:la")
I am trying to read value from DB using c#.
The query string contains multiple single quotes - such as: Esca'pes' (the query strings are being read from a text file)
So, I wanted to replace all the single quotes with two single quotes before forming the SQL query. My code is as below:
if (name.Contains('\''))
{
name = name.Replace('\'','\''');
}
How to fix this?
Use strings, not char literals.
name = name.Replace("'", "''");
However it sounds like you're concatenating SQL strings together. This is a huge "DO NOT" rule in modern application design because of the risk of SQL injection. Please use SQL parameters instead. Every modern DBMS platform supports them, including ADO.NET with SQL Server and MySQL, even Access supports them.
name = name.Replace("'","''");
On an unrelated note, you're concatenating strings for use in SQL? Try parameters instead, that's what they're meant for. You're probably making it harder than it needs to be.
Since you want to replace a single character with two characters, you need to use the String overload of Replace
if (name.Contains('\''))
{
name = name.Replace("'","''");
}
(Note: single quotes don't require escaping in Strings like they do in character notation.)
I have a string
good overview of ESP's in more detail than you probably need.
While inserting into SQL table it is giving error. So I want replace apostrophe in the string with double apostrophe like
good overview of ESP''s in more detail than you probably need
How to manipulate this in c#?
Very easy:
string s = "good overview of ESP's in more detail than you probably need.";
string escaped = s.Replace("'","''");
Note: It is usually safer to use command parameters. Especially if the values of the input strings are not controlled by your code (i.e. user entries).
Use the Parameter object.
myCommand.InsertCommand.Parameters.Add("#myString", SqlDbType.VarChar, 200);
myCommand.InsertCommand.Parameters["#myString"].Value = #"good overview of ESP's in more detail than you probably need.";
I was working on this problem for ages. Do it on the client, replacing the single quote with two single quotes. This works if you are executing an sp with several varchar input parameters. The only problem with this is SQL injection i.e. people can see what you are up to on the client which is never a good thing. The only way round this is to use SQLparameters on the server, as they have said earlier.
String.Replace(String,String) should work fine. In this example, you'd want:
String.Replace("'", "''")
However, I don't think that that'll fix your issue. I imagine you're more appropriately looking for:
String.Replace("'", "\'")
The reason for this being that MySQL, and I'd imagine other versions of SQL, expect strings to be enclosed in single quotes.
myCommand.InsertCommand.Parameters.Add("#myString", SqlDbType.VarChar, 200);
myCommand.InsertCommand.Parameters["#myString"].Value
Is there a heredoc notation for strings in C#, preferably one where I don't have to escape anything (including double quotes, which are a quirk in verbatim strings)?
As others have said, there isn't.
Personally I would avoid creating them in the first place though - I would use an embedded resource instead. They're pretty easy to work with, and if you have a utility method to load a named embedded resource from the calling assembly as a string (probably assuming UTF-8 encoding) it means that:
If your embedded document is something like SQL, XSLT, HTML etc you'll get syntax highlighting because it really will be a SQL (etc) file
You don't need to worry about any escaping
You don't need to worry about either indenting your document or making your C# code look ugly
You can use the file in a "normal" way if that's relevant (e.g. view it as an HTML page)
Your data is separated from your code
Well even though it doesn't support HEREDOC's, you can still do stuff like the following using Verbatim strings:
string miniTemplate = #"
Hello ""{0}"",
Your friend {1} sent you this message:
{2}
That's all!";
string populatedTemplate = String.Format(miniTemplate, "Fred", "Jack", "HelloWorld!");
System.Console.WriteLine(populatedTemplate);
Snagged from:
http://blog.luckyus.net/2009/02/03/heredoc-in-c-sharp/
No, there is no "HEREDOC" style string literal in C#.
C# has only two types of string literals:
Regular literal, with many escape sequences necessary
Verbatim literal, #-quoted: doublequotes need to be escaped by doubling
References
csharpindepth.com - General Articles - Strings
MSDN - C# Programmer's Reference - Strings
String literals are of type string and can be written in two forms, quoted and #-quoted.
November 2022 update:
Starting with C# 11 this is now possible using Raw string literals:
var longMessage = """
This is a long message.
Some "quoted text" here.
""";