Is mysql_real_escape_string() Truly Reliable for Preventing SQL Injection?

Can You Rely on mysql_real_escape_string() to Safeguard Your Queries?

Despite proper usage, concerns have been raised regarding the reliability of mysql_real_escape_string() in safeguarding against SQL injections. To shed light on this issue, let's delve into the function's limitations and its suitability for creating custom prepared statements.

Proof Code and Analysis:

According to the official MySQL documentation, mysql_real_escape_string()'s function is affected by the character set of the connection. To ensure optimal performance, it suggests using mysql_set_character_set() rather than SET NAMES or SET CHARACTER SET statements to modify the character set.

#include <mysql/mysql.h>

int main() {
  // Create a MySQL connection
  MYSQL *conn = mysql_init(NULL);

  // Set the character set to UTF-8 using mysql_set_character_set()
  mysql_set_charset(conn, "utf8", MY_CS_PRIMARY);

  // Prepare a query using mysql_real_escape_string()
  char *query = mysql_real_escape_string(conn, "SELECT * FROM users");

  // Execute the query
  mysql_query(conn, query);

  // Release memory
  free(query);
  mysql_close(conn);

  return 0;
}

In this code, we explicitly set the character set to UTF-8 using mysql_set_character_set(), ensuring that mysql_real_escape_string() is used with the correct encoding.

Conclusion:

While certain limitations may exist, mysql_real_escape_string() can still be utilized to create rudimentary prepared statements. By ensuring the appropriate character set is defined using mysql_set_character_set(), you can maintain the desired level of security against SQL injections.

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