Set Escape in a View - sql

I currently am attempting to run a script which contains a case statement where I need to match on the string 'Prod. & Mat.'
When running the script in a worksheet, I simply precede my entire script by running,
set escape '\'
Then I run my select statement which includes the case portion written as 'Prod. \& Mat.'
All matches up as expected. However, I need to generate this same script in a view. As you know the view begins with the header...
Create or replace force view "database.table" as .....
My problem, I cannot figure out how/get the view to run and acknowledge the set escape '\' piece, so my results do not match to my 'Prod. & Mat.' portion.
How or where do I insert my set escape clause, or is there another way to avoid the & problem within a view?

Try adding set define offbefore running your create view script, and then set define on afterwards, if you want ampersands to represent parameters again.
That way, & is treated as just another character - there will be no need to escape it.

Related

Escape character within single quotes

I'm having an issue figuring out how to ignore signs and variables in a single quote string statement.
I am attempting to update a table with the new text with structure such as:
update xxx
set xxx =
'Our Ref. $BOOKING_NO$
.......
Kind regards'
If your $ chars are being interpreted, it isn't by Oracle ($ isn't special in Oracle anyway, and between single-quotes everything is a string), but rather by your client program or maybe shell script. If, for example, you are running this in SQL*Plus from a Unix-based shell script, you will need to use the appropriate means required by the shell you use to prevent the shell from interpreting $ and ' characters.

Getting Unescaped JSON from SQL

I've created a stored procedure to pull data as a JSON object from my SQL Server database. All my data is relational and I'm trying to get it out as a JSON string.
Currently, I am able to get out a JSON string from SQL Server just fine, however this object ALWAYS includes escape characters (e.g. "{\"field\":\"value\"}). I'd like to pull the same JSON but without escaped characters. To test this I'm using some simple queries and getting them into .NET with a SqlDataAdapter using my stored procedure.
The thing that puzzles me is that when I run my query within SSMS, I never see any escape characters, but as soon as it's pulled a .NET application, the escape characters appear. I'd like to prevent this from happening and have my applications get only the unescaped JSON string.
I've tried several suggestions I've found during my research but nothing has produced my desired results. The changes I've seen (documented in MSDN and in other SO posts) have dealt with getting unescaped results, but only within SSMS and not within other applications.
What I've tried:
Simple Json query set to param and then using JSON_QUERY to select the param:
DECLARE #JSON varchar(max)
SET #JSON = (SELECT '{"Field":"Value"}' AS myJson FOR JSON PATH)
SELECT JSON_QUERY(#JSON) AS 'JsonResponse' FOR JSON PATH
This produces the following in a .NET application:
"[{\"JsonResponse\":{\"Field\":\"Value\"}}]"
This produces the following in SSMS:
[{"JsonResponse":[{"myJson":"{\"Field\":\"Value\"}"}]}]
Simple Json query without param using JSON_QUERY:
SELECT JSON_QUERY('{"Field":"Value"}') AS 'JsonResponse' FOR JSON PATH
This produces the following in a .NET application
"[{\"JsonResponse\":{\"Field\":\"Value\"}}]"
This produces the following in SSMS
[{"JsonResponse":{"Field":"Value"}}]
Simple Json query with temp tables using JSON_QUERY:
CREATE TABLE #temp(
jsoncol varchar(255)
)
INSERT INTO #temp VALUES ('{"Field":"Value"}')
SELECT JSON_QUERY(jsoncol) AS 'JsonResponse' FROM #temp FOR JSON PATH
DROP TABLE #temp
This produces the following in a .NET application:
"[{\"JsonResponse\":{\"Field\":\"Value\"}}]"
This produces the following in SSMS:
[{"JsonResponse":{"Field":"Value"}}]
I'm lead to believe that there is no way to get out a JSON string from SQL Server without having the escaped characters. In case the examples above weren't enough, I've included my stored procedure here. Hopefully someone can point me in the right direction.
This depends where you look at the string...
In SSMS a string is marked with single quotes. The double quote can exist within a string without problems:
DECLARE #SomeString = 'This can include "double quotes" but you have to double ''single quote''';
In a C# application the double quote is the string marker. So the above example would look like this:
string SomeString = "This must escape \"double quotes\" but you can use 'single quote' without problems";
Within your IDE (is it VS?) you can look at the string as is or as you'd need to be used in code. Your example shows " at the beginning and at the end of your string. That is a clear hint, that this is the option as in code. You could use this string and place it into your code. The real string, which is used and processed will not contain escape characters.
Hint: Escape characters are only needed in human-readable formats, where there are characters with special meaning (a ; in a CSV, a < in HTML and so on)...
UPDATE Some more explanation
Escape characters are needed to place a string within a string. Somehow you have to mark the beginning and the end of the string, but there is nothing else you can use then some magic characters.
In order to use these characters within the embedded string you have to go one the following ways:
escaping (e.g. XML will replace & with & and JSON will replace a " with \" as JSON uses the " to mark its labels) or
Magic borders (e.g. a CDATA-section in XML, which allows to place unescaped characters as is: <![CDATA[forbidden characters &<> allowed here]]>)
Whatever you do, you must distinguish between the visible string in an editor or in a text-based container like XML or JSON and the value the application will pick out of this.
An example:
<root><a>this & that</a></root>
visible string: "this & that"
real value: "this & that"

Tcl SQLite update variable substitution cannot have apostrophe

Here's the problem: if I use { } for the update command like so:
package require sqlite3
fileRepo eval {UPDATE uploads SET $col=$data WHERE rowid=$id}
I cannot substitute any variables inside the curly brackets. it all has to be hard coded.
However, if I use " " for the update command like so:
fileRepo eval "UPDATE uploads SET $col='$data' WHERE rowid=$id"
I can substitute variables inside the double quotes, but I must use ' ' in order to put in data with spaces so sql sees it as one input. If I don't I get an error if I send something like
$data = "Legit Stack"
Because it has a space the sql will choke on the word: Stack
unless it is placed within single quotes
Therefore...
If I send this data to the update command:
$col = description
$data = "Stack's Pet"
I get the following error:
near "s": syntax error while executing "fileRepo eval "UPDATE uploads
SET $col='$data' WHERE rowid=$id" ...
Thus given these rules I can see no way to pass a single quote or apostrophe to the update command successfully. Is there a different way to do this?
Thanks!
While it is true that you can escape the single quotes by doubling them (as usual in SQL), you open up your code to the dangers of SQL injection attacks.
It might be better to split your code into two distinct steps:
Substitute with format {UPDATE uploads SET %s=$data WHERE rowid=$id} $col
let sqlite3 magic eval turn the $data and $id into bound variables for a prepared statement
This way you only need to sanitize your col variable, to make sure it contains a valid column name and nothing else (should be easy), instead of all your data. In addition, you do not need to copy large values as often, so a two step approach will even be faster. To make it even clearer you want to use a bind variable, try the alternative syntax with a : in front of a variable name.
package require sqlite3
set stmt [format {UPDATE uploads SET %s=:data WHERE rowid=:id} $col]
fileRepo eval $stmt
Recommended Reading:
For the : syntax: https://www.sqlite.org/tclsqlite.html#eval
For more information about SQL Injections: https://www.owasp.org/index.php/SQL_Injection_Prevention_Cheat_Sheet
You have to use an escape apostrophe. So it should look like this:
$data = "Stack''s Pet"

Jmeter is removing the space at end of variable in Select statement but otherwise fine

In Jmeter I have a variable that has been defined with a space at the end. I can verify in Results Tree Response that the HTTP POST has the variable substitution correct with an extra + at the end and thus know the variable and its space is being passed correctly. Good.
Now, when the same variable is used in a select statement in apostropes, select * from whatever where value='${blah}' what happens is that I see in the Results Tree that the space is missing. The Jmeter variable substitution in the select statement is correct for its text, but it is missing the space at the end, it removes the space.
Since the variable otherwise works correctly, how to allow the select statement to not truncate the space?
Cheers
Try using jmeter unescape method it cleaned up those nasty '+' at the end of each variable it was parsing.
Here the complete syntaxt if you are using it in a http request parameter: ${__unescape(${myVariableName})}
see 19.1 http://jmeter.apache.org/usermanual/functions.html
for more info on jmeter function

How do I ignore ampersands in a SQL script running from SQL Plus?

I have a SQL script that creates a package with a comment containing an ampersand (&). When I run the script from SQL Plus, I am prompted to enter a substitute value for the string starting with &. How do I disable this feature so that SQL Plus ignores the ampersand?
This may work for you:
set define off
Otherwise the ampersand needs to be at the end of a string,
'StackOverflow &' || ' you'
EDIT: I was click-happy when saving... This was referenced from a blog.
If you sometimes use substitution variables you might not want to turn define off. In these cases you could convert the ampersand from its numeric equivalent as in || Chr(38) || or append it as a single character as in || '&' ||.
I resolved with the code below:
set escape on
and put a \ beside & in the left 'value_\&_intert'
Att
You can set the special character, which is looked for upon execution of a script, to another value by means of using the SET DEFINE <1_CHARACTER>
By default, the DEFINE function itself is on, and it is set to &
It can be turned off - as mentioned already - but it can be avoided as well by means of setting it to a different value. Be very aware of what sign you set it to. In the below example, I've chose the # character, but that choice is just an example.
SQL> select '&var_ampersand #var_hash' from dual;
Enter value for var_ampersand: a value
'AVALUE#VAR_HASH'
-----------------
a value #var_hash
SQL> set define #
SQL> r
1* select '&var_ampersand #var_hash' from dual
Enter value for var_hash: another value
'&VAR_AMPERSANDANOTHERVALUE'
----------------------------
&var_ampersand another value
SQL>
set define off <- This is the best solution I found
I also tried...
set define }
I was able to insert several records containing ampersand characters '&' but I cannot use the '}' character into the text
So I decided to use "set define off" and everything works as it should.
According to this nice FAQ there are a couple solutions.
You might also be able to escape the ampersand with the backslash character \ if you can modify the comment.
I had a CASE statement with WHEN column = 'sometext & more text' THEN ....
I replaced it with
WHEN column = 'sometext ' || CHR(38) || ' more text' THEN ...
you could also use
WHEN column LIKE 'sometext _ more text' THEN ...
(_ is the wildcard for a single character)