I have an update query that updates a column that holds another application SQL query.
Putting SQL inside has been problematic I wanted to resolve it with escape characters.
update
my_table
set
sql_column = 'UPDATE inner_table SET user_name=\'user_name\' text=\'this this free text with things like \" inside it and drives me made\''
where
condition_col = 123456
The above is correct in any SQL syntax checker; however, Sybase throws an error simply Incorrect syntax new 'username.'
I am new to Sybase; please help.
I was expecting that Sybase would behave like MySQL, which is different.
Sybase (and ansi-standard SQL*) escapes the single quote with itself. You don't need to do anything special with a double quote inside a string literal (since in ansi-standard SQL double quotes do not create literals).
sql_column = 'UPDATE inner_table SET user_name=''user_name'' text=''this this free text with things like \\" inside it ...'
But Sybase will NOT behave like MySQL (it's far more standards compliant).
Lacking some context here, but this kind of code is also likely to end up leaving you dangerously susceptible to SQL injection issues, and that's a really big deal.
* The link is for Informix, but it does a good job explaining the standard
These is one keyword confliction issue in the query module of my application,please see if you can tell me a smart solution.
First,In query module,each query condition contains three parts in UI:
1.field name,its value is fixed,e.g origin,finalDest...
2.operator,it is a select list which includes "like","not like","in","not in","=","!="
3.value,this part is input by user.then in back-end,it will assemble the SQL statement according to UI's query criteria,e.g if user type/select following stuff in UI
Field Name Operator Value
origin like CHI
finalDest in SEL
In back-end,it will generate following SQL:
select * from Booking where origin like '%CHI%' and finalDest in ('SEL').
But there is a bug,e.g if user type some of special symbol in "value",e.g "'","_" etc,it will lead to the generated SQL also contain ' or _ ,e.g:
select * from Booking where origin like '%C_HI%' and finalDest in ('S'EL').
you could see as there is special symbol in "where" block,the SQL can't be executed
For this problem,my solution is add escape character "/" in front of the special symbol before executing it,but what i know is just ' or _ that would conflict with the SQL keywords,do you know if there is any others similar symbol that i need to handle or do you guys have any better idea that can avoid the injection
Sorry,forgot told you what language i am using,i am using java,the DB is mysql,i also use hibernate,there are a lot of people said why i didn't use PreparedStatement,this is a little complex,simply speaking,in my company,we had a FW called dynamic query,we pre-defined the SQL fragment in a XML file,then we will assemble the SQL according to the UI pass in criteria with the jxel expression,as the SQL is kinda of pre-defined stuff,i afraid if change to use PreparedStatement,it will involve a lot of change for our FW,so what we care is just on how to fix the SQL injection issue with a simple way.
The code should begin attempting to stop SQL injection on the server side prior to sending any information to the database. I'm not sure what language you are using, but this is normally accomplished by creating a statement that contains bind variables of some sort. In Java, this is a PreparedStatement, other languages contains similar features.
Using bind variables or parameters in a statement will leverage built in protection against SQL injection, which honestly is going to be better than anything you or I write on the database. If your doing any String concatenation on the server side to form a complete SQL statement, this is an indicator of a SQL injection risk.
0 An ASCII NUL (0x00) character.
' A single quote (“'”) character.
" A double quote (“"”) character.
b A backspace character.
n A newline (linefeed) character.
r A carriage return character.
t A tab character.
Z ASCII 26 (Control+Z). See note following the table.
\ A backslash (“\”) character.
% A “%” character. See note following the table.
_ A “_” character. See note following the table
Reference
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You should use bind variables in your SQL statement. As already mentioned this is done with PreparedStatements in Java.
To make sure, only valid column names are used, you can validate the input against the database. MySQL provides schema information like columns of each table as part of the INFORMATION_SCHEMA. For further information, check the MySQL documentation:
"The INFORMATION_SCHEMA COLUMNS Table"
I am concerned about inserting text in a MySQl table w.
I have to insert/update text that contains characters such as / " and '
The escape character / could be inserted only if the NO_BACKSLASH_ESCAPES SQL mode is enabled. wich interfere with the characters " and ' see this link http://dev.mysql.com/doc/refman/5.1/en/string-literals.html#character-escape-sequences
If anyone can explain to is in earth the mysql_real_escape_string() I don't came to understated
I would like to find a pure mysql solution
I am not using php. What I am trying to do here is to "simulate " Content Management System: I am about to write a C# coded solution that manage the content in its different forms(article, category ,tag, etc..) and generate .html files, the MySQl database is local in my computer next i will upload the .html files to the server.
I did this to ensure that all my html pages are html valid and because I don't trust any existent solutions (not only when it concerns coding but in life in general)
Please help
each php db connection extension (mysql, mysqli, pdo) has a special way to safe query against sql injections, when you are using mysql extension, it's strongly recommended to use mysql_real_escape_string() function to make safe all variables used in query, it's most widely used function. i think there isn't any pure solution (when you are using mysql extension in php).
from php.net:
mysql_real_escape_string()-Escapes special characters in the
unescaped_string, taking into account the current character set of the
connection so that it is safe to place it in a mysql_query().
Whatever string data can be inserted into SQL query, if formatted according to 2 rules
it is enclosed in quotes (preferably single ones)
it is passed through mysql_real_escape_string()
if both rules followed, there would be not a single problem with whatever characters, either slashes, quotes or anything.
According to your question, / has no special meaning in MySQL. It's \ that is escape character. It can be escaped by another backslash as well.
$str = 'slashes \ quotes \' or whatever " else symbols';
var_dump($str);
$str = mysql_real_escape_string($str);
$sql = "INSERT INTO table SET str='$str'";
My SQL Server 2008 R2 database has string columns (nvarchar). And some of the old data is showing Ascii. I need to show it to the user in my site and I prefer to convert the data in the database to Unicode. Is there a quick way to do this? are there downsides that I should be aware of?
Examples to my issue:
In the database, I see special chars instead of regulars chars. I have a name of a user which is supposed to be Amédée, and instead it shows Am?d??.
In other cases I see " instead of Quotation mark ("), or the chars &# instead of the word "and".
I want to Remove Invalid unicode Characters from a field in sql server.
How to achieve that?
What exactly do you count as "invalid" characters?
What is the data-type of the field (char/varchar) or (nchar/nvarchar)
What you may find is that this is an instance where a SQLCLR function to take a SqlString as an input and return a SqlString.
You can then use the more powerful .NET String-manipulation, Encoding, and Globalization features.