This topic is applicable to Entity Framework v1 - v6. It is not applicable to Entity Framework Core because Entity Developer generates ADO.NET code for invoking stored procedures in this case.
Entity Framework has limited support for stored routines. Stored routines can be used for mapping insert, delete, and update operations and for creating methods returning collections of entities or scalar objects by using Function Import. Stored functions that were added to the storage model can be invoked with Entity SQL, but cannot be invoked directly in the LINQ to Entities.
Stored routine parameter types have the same constraint as the table and view columns - they should be primitive non-object types. REF CURSOR out parameters and stored functions, returning cursors are also supported. Stored procedures, having more than one REF CURSOR out parameters cannot be supported completely and return only one result set.
Microsoft implementation of run-time and design-time tools for Entity Framework is targeted to the users of MS SQL Server. Current functionality doesn't provide full support for specific features of Oracle stored routines.
Main disadvantages:Entity Developer is designed for creating Entity Framework model visually, saving the user from editing XML manually. It provides you with completely editable storage model, including the dialog box for creating and editing command text. Drag-n-drop support from the Database Explorer eases model updating. Oracle specific features, such as returning result set using REF CURSORs and stored procedures from packages are considered. Flexible and customizable code generation supports all types of methods, created with Function Import.
Entity Framework Tutorial | Using Entity Data Model Wizard | Creating Database and Model | Stored Procedure Returning Result Set using REF CURSOR Out Parameter | Stored Function Returning REF CURSOR | Mapping CUD Operations to Stored Routines