| = Custom SQL Functions |
| |
| :javaFile: {javaCodeDir}/SqlAPI.java |
| |
| The SQL Engine can extend the SQL functions' set, defined by the ANSI-99 specification, via the addition of custom SQL functions written in Java. |
| |
| A custom SQL function is just a public static method marked by the `@QuerySqlFunction` annotation. |
| |
| //// |
| TODO looks like it's unsupported in C# |
| //// |
| |
| |
| [source,java] |
| ---- |
| include::{javaFile}[tags=sql-function-example, indent=0] |
| ---- |
| |
| |
| The class that owns the custom SQL function has to be registered in the `CacheConfiguration`. |
| To do that, use the `setSqlFunctionClasses(...)` method. |
| |
| [source,java] |
| ---- |
| include::{javaFile}[tags=sql-function-config, indent=0] |
| ---- |
| |
| Once you have deployed a cache with the above configuration, you can call the custom function from within SQL queries: |
| |
| [source,java] |
| ---- |
| include::{javaFile}[tags=sql-function-query, indent=0] |
| ---- |
| |
| NOTE: Classes registered with `CacheConfiguration.setSqlFunctionClasses(...)` must be added to the classpath of all the nodes where the defined custom functions might be executed. Otherwise, you will get a `ClassNotFoundException` error when trying to execute the custom function. |
