This is a simple attack, but numerous other scripted SQL statements are available to test your input. You must be able to secure your website from these attacks using logic understanding how a SQL statement could be built and some built-in tools available with most common web languages. The methods that you use to defend against SQLi depend on the language and platform you're programming on. One common way to defend against SQLi is to move inline SQL string statements from code to database stored procedures.
Stored procedures will translate the SQLi statements as literals, which means it won't transfer the SQL statements as executable code but rather as literal string values the database will use as input parameters.
The result is that the statements will return no values. If you're using Microsoft. In the previous section's examples, PHP was used to build strings. WordPress is often targeted because developers can't get access to a site's database to use stored procedures when they upload to the WordPress repository for public download. WordPress developers use inline SQL often, and that's why even some common, popular plugins have been compromised.
PHP developers suggest using prepared statements. Prepared statements parameterize your queries, which makes them similar to stored procedures. Instead of building strings, prepared statements use symbols to indicate where you want to insert values, and these values are taken as literals. As of PHP 5. First, we need to create the database connection and instantiate the PDO object.
Notice that the prepared statement uses :id to indicate that this is where the variable is located. With the PDO object, you then assign a value to the variable using input from the user. What I term as inline sql is SQL strings within source code. There used to be design debates over SQL strings in source code detracting from the fundamental intent of the logic, which is why statically typed linq style queries became so popular its still just 1 language, but with lets say C and Sql in one page you have 2 languages intermingled in your raw source code now.
Just to clarify, the SQL injection is just one of the known issues with using sql strings, I already mention you can stop this from happening with parameter based queries, however I highlight other issues with having SQL queries ingrained in your source code, such as the lack of DB Vendor abstraction as well as losing any level of compile time error capturing on string based queries, these are all issues which we managed to side step with the dawn of ORMs with their higher level querying functionality, such as HQL or LINQ etc not all of the issues but most of them.
So I am less focused on the individual highlighted issues and more the bigger picture of is it now becoming more acceptable to have SQL strings directly in your source code again, as most Micro ORMs use this mechanism.
Here is a similar question which has a few different view points, although is more about the inline sql without the micro orm context:. What you are describing as "Inline SQL" should really be called "string concatenation without parameterization," and you don't have to do that to use a Micro ORM safely. All SQL Injection safe. Or, maybe you simply want to avoid the complexity of generating all those proxy classes.
Remember, the ADO. I love sql , and couldn't stand seeing it chopped up in string literals, so I wrote a little VS extension to let you work with real sql files in c projects. Editing sql in its own file gives you intellisense for columns and tables, syntax validation, test execution, execution plans and the rest.
When you save the file, my extension generates c wrapper classes, so you never write a line of connection code, or command code, or parameter or reader code. Your queries are all parameterized because there's no other way, and you have generated repositories and POCOs for unit testing, with intellisense for your input parameters and your results.
And I've thrown in free steak knives When an expert needs to come and rework your developer's sql, she's looking at a real sql file, and doesn't need to touch any C. When she goes back and tidies up the DB, deleting some columns, references to missing columns jump straight out as compile errors in the c. The database becomes just like another project in your solution that you can hack into, it's interface discoverable in code.
If the solution compiles, you know that all your queries are working. There are no runtime errors due to invalid casts or invalid column names, or invalid queries. Lookin back at dapper, which we're still using at work, I can't believe that in this is the coolest thing in data access. Runtime msil generation is clever n all, but all the errors are runtime errors, and string manipulation, like string manipulation for any other purpose, is time consuming, fragile and error prone.
And how can it be Dry to have to repeat your column names in your POCO, which you have to write and maintain by hand. So there you go. If you want to look at an unkown data-access technology from an unheard of developer working in his spare time with a young child and lots of other hobbies , it's over here.
Parameterized queries as well as the repository design pattern give you full control over what goes into the query to prevent injection attacks. Inline SQL in this case is not an issue other than readability for large and complex queries, which should be in stored procedures anyway.
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Create a free Team What is Teams? Learn more. Ask Question. My two questions are: 1 how can the query planner make performance orders of magnitude worse while it is trying to optimize my embedded inline functions? Other than converting it to a non-inline function, that is. The planner could try to seamlessly embed the function? It's even "worse". The optimizer the "planner" as you call it does not even know that there is a function. During the process known as binding the optimizer replaces views, CTE and inline table-valued functions with their definitions and that's what the optimizer works with.
Permit me to point out that in many cases this is what you want, and the usability of views and inline functions would be terribly reduced if it not happen. Say for instance that you want a view that for each order also has the order sum:. No, you want it to use the index on CustomerID to only retrieve those orders. Back to your problem. The phenomenon you describe is not unheard of, but it necessarily not related to functions.
But more generally, if you have large query with many tables, it is very difficult for the optimizer to accurately estimate the cost for tables access later in the plan, even if statistics are up to date. A small error can easily explode into a large one. One technique to tackle this is indeed to materialise an intermediate result into a temp table, so that the optimizer can work with more accurate statistics for the next step.
So that may very well be the solution in your case: receive the data in a temp table and work with that table. There is an alternative, but I mention it with some anxeity. Not because that is is bad, but because if you don't understand it well, it can easily lead to abuse. There is no space here to develop this in full, and it would also be unfair to so.
The optimizer will still work with the expanded query, but the TOP operator will serve as a barrier for re-casting computation order. But as I noted, this is not always what you want.
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