How can prepared statements protect from SQL injection attacks?

Question

How do prepared statements help us prevent SQL injection attacks?

Wikipedia says:

Prepared statements are resilient against SQL injection, because

Answer 1

Root Cause #1 - The Delimiter Problem

Sql injection is possible because we use quotation marks to delimit strings and also to be parts of strings, making it impossible to interpret them sometimes. If we had delimiters that could not be used in string data, sql injection never would have happened. Solving the delimiter problem eliminates the sql injection problem. Structure queries do that.

Root Cause #2 - Human Nature, People are Crafty and Some Crafty People Are Malicious And All People Make Mistakes

The other root cause of sql injection is human nature. People, including programmers, make mistakes. When you make a mistake on a structured query, it does not make your system vulnerable to sql injection. If you are not using structured queries, mistakes can generate sql injection vulnerability.

How Structured Queries Resolve the Root Causes of SQL Injection

Structured Queries Solve The Delimiter Problem, by by putting sql commands in one statement and putting the data in a separate programming statement. Programming statements create the separation needed.

Structured queries help prevent human error from creating critical security holes. With regard to humans making mistakes, sql injection cannot happen when structure queries are used. There are ways of preventing sql injection that don't involve structured queries, but normal human error in that approaches usually leads to at least some exposure to sql injection. Structured Queries are fail safe from sql injection. You can make all the mistakes in the world, almost, with structured queries, same as any other programming, but none that you can make can be turned into a ssstem taken over by sql injection. That is why people like to say this is the right way to prevent sql injection.

So, there you have it, the causes of sql injection and the nature structured queries that makes them impossible when they are used.