A SQLi attack involves inserting a malformed query into an application via client-side input. The attack perverts the intentions of web programmers who write queries and provide input methods that can be exploited. The underlying flaws enabling SQLi attacks are introduced when developers create dynamic database queries that include user input. AlienVault Unified Security Management (USM) can help you detect these attacks and answer the questions above with several integrated security technologies including host-based IDS, network IDS and real-time threat intelligence.
Source: https://thehackernews.com/2014/09/how-to-detect-sql-injection-attacks.html