In this thesis we address the problem of integrating general purpose programming languages with relational databases. An approach to solving this problem is using raw strings to represent SQL statements. This approach leads to runtime errors and security vulnerabilities like SQL injection. The second approach is integrating the query in a host language. The most well-known example of the second approach is LINQ. This approach provides static checking of types and syntax during compilation. This thesis presents an embedded query language in Scala, namely Shadow Embedding in Slick. Shadow Embedding provides even stronger compile-time guarantees than LINQ and similar systems in Scala. The experimental results show that the performance of our approach is very similar to the case of using raw Strings, thanks to static code analysis and clever code caching.