Note: If your application is a web application and the above entry was added to a web.config and the same config section handler for "oracle.manageddataaccess.client" also exists in machine.config but the "Version" attribute values are different, an error message of "There is a duplicate 'oracle.manageddataaccess.client' section defined." may be observed at runtime. If so, the config section handler entry in the machine.config for "oracle.manageddataaccess.client" has to be removed from the machine.config for the web application to not encounter this error. But given that there may be other applications on the machine that depended on this entry in the machine.config, this config section handler entry may need to be moved to all of the application's .NET config file on that machine that depend on it. 2) DbProviderFactories The following entry is added for applications that use DbProviderFactories and DbProviderFactory classes. Also, any DbProviderFactories entry for "Oracle.ManagedDataAccess.Client" in the machine.config will be ignored with the following entry: 3) Dependent Assembly The following entry is created to ignore policy DLLs for Oracle.ManagedDataAccess.dll and always use the Oracle.ManagedDataAccess.dll version that is specified by the newVersion attribute in the element. The newVersion attribute corresponds to the Oracle.ManagedDataAccess.dll version which came with the NuGet package associated with the application. 4) Data Sources The following entry is added to provide a template on how a data source can be configured in the app/web.config. Simply rename "MyDataSource" to an alias of your liking and modify the PROTOCOL, HOST, PORT, SERVICE_NAME as required and un-comment the element. Once that is done, the alias can be used as the "data source" attribute in your connection string when connecting to an Oracle Database through ODP.NET, Managed Driver. The following app/web.config entries are added by including the "ODP.NET, Managed Entity Framework Driver - Official" NuGet package to your application. 1) Entity Framework The following entry is added to enable Entity Framework to use Oracle.ManagedDataAccess.dll for executing Entity Framework related-operations, such as Entity Framework Code First and Entity Framework Code First Migrations against the Oracle Database. 2) Connection String The following entry is added to enable the classes that are derived from DbContext to be associated with a connection string instead to associating the derived class with a connection string programmatically by passing it via its constructor. The name of "OracleDbContext" should be changed to the class name of your class that derives from DbContext. In addition, the connectionString attribute should be modified properly to set the "User Id", "Password", and "Data Source" appropriately with valid values. Documentation Corrections and Additions ======================================= This section contains information that corrects or adds to existing ODP.NET documentation, which can be found here: http://docs.oracle.com/cd/E56485_01/index.htm Custom Entity Data Model (EDM) Type Mapping Not Applied to Generated Complex Types --- When using the EDM wizard to create a complex type from a function import, any custom EDM type mappings specified will not be applied. The EDM wizard uses the default type mappings and the only known workaround is to manually edit the resulting complex type. After the complex type is generated any type declaration (field, property, constructor parameter, etc.) in the complex object which has an undesired type (such as Decimal rather than Boolean) should be manually edited to be of the desired type. ODP.NET, Managed Driver Support for Oracle Database 12c Implicit Ref Cursor --- ODP.NET, Managed Driver introduces support for the new Oracle Database 12c Implicit Ref Cursor. Configuration occurs using the .NET configuration section. When using database implicit ref cursors, the bindInfo element should be specified with a mode of "Implicit": For additional information refer to the implicitRefCursor section in Chapter 2 of the Oracle Data Provider for .NET Developer's Guide. Entity Framework Code First: Code-Based Migrations With No Supporting Code Migration File --- When using code-based migrations with the Entity Framework provider, the migration history table may be dropped if no supporting code migration file existed prior to updating the database. Workaround: Ensure the supporting code migration file has been added prior to updating the database. The following steps can remove the migration history table: 1. Execute application to create database objects 2. Enable-Migrations 3. Make code change to POCO 4. Update-Database The workaround is to ensure code file is created: 1. Execute application to create database objects 2. Enable-Migrations 3. Make code change to POCO 4. Add-Migration (This step will create the necessary code migration file). 5. Update-Database Session Time Zone Hour Offset in ODP.NET Managed and Unmanaged Drivers --- ODP.NET managed and unmanaged drivers set the default session time zone differently. While the session time zone for unmanaged ODP.NET uses an hour offset, managed ODP.NET uses the region identifier for setting its session time zone. As a result, managed ODP.NET is sensitive to daylight savings in scenarios where the timestamp LTZ values have to be converted from/to the session time zone. There are two methods to resolve this difference if needed. For ODP.NET, Unmanaged Driver, the application explicitly sets the region identifier with the environment variable 'ORA_SDTZ' (e.g. 'set ORA_SDTZ = '). If ORA_SDTZ variable is set, Oracle Client considers this value as the session time zone. The second method is to execute an alter session command to set the session time zone property to the region identifier. ODP.NET, Managed Driver with NTS Authentication --- ODP.NET, Managed Driver supports NTS authentication to the database, except when the Windows domain is constrained to only support Kerberos-based domain authentication. ODP.NET, Managed Driver SSL Connections with Firewalls --- ODP.NET, Managed Driver SSL connections require a redirect to a dynamic port on the database server side. If a firewall exists between the database client and server, then all firewall ports must be enabled or the dynamic firewall port Oracle chooses must be enabled at run-time. ODP.NET, Managed Driver Tips, Limitations, and Known Issues =========================================================== This section contains information that is specific to ODP.NET, Managed Driver. 1. OracleConnection object's OpenWithNewPassword() method invocation will result in an ORA-1017 error with 11.2.0.3.0 and earlier versions of the database. [Bug 12876992] 2. Stored functions/procedures in a PDB cannot be added to a .NET Entity Framework model. [Bug 17344899] Entity Framework Tips, Limitations, and Known Issues ==================================================== This section contains Entity Framework related information that pertains to both ODP.NET, Managed Driver and ODP.NET, Unmanaged Driver. 1. Interval Day to Second and Interval Year to Month column values cannot be compared to literals in a WHERE clause of a LINQ to Entities or an Entity SQL query. 2. LINQ to Entities and Entity SQL (ESQL) queries that require the usage of SQL APPLY in the generated queries will cause SQL syntax error(s) if the Oracle Database being used does not support APPLY. In such cases, the inner exception message will indicate that APPLY is not supported by the database. 3. ODP.NET does not currently support wildcards that accept character ranges for the LIKE operator in Entity SQL (i.e. [] and [^]). [Bug 11683837] 4. Executing LINQ or ESQL query against tables with one or more column names that are close to or equal to the maximum length of identifiers (30 bytes) may encounter "ORA-00972: identifier is too long" error, due to the usage of alias identifier(s) in the generated SQL that exceed the limit. 5. An "ORA-00932: inconsistent datatypes: expected - got NCLOB" error will be encountered when trying to bind a string that is equal to or greater than 2,000 characters in length to an XMLType column or parameter. [Bug 12630958] 6. An "ORA-00932 : inconsistent datatypes" error can be encountered if a string of 2,000 or more characters, or a byte array with 4,000 bytes or more in length, is bound in a WHERE clause of a LINQ/ESQL query. The same error can be encountered if an entity property that maps to a BLOB, CLOB, NCLOB, LONG, LONG RAW, XMLTYPE column is used in a WHERE clause of a LINQ/ESQL query. 7. An "Arithmetic operation resulted in an overflow" exception can be encountered when fetching numeric values that have more precision than what the .NET type can support. In such cases, the LINQ or ESQL query can "cast" the value to a particular .NET or EDM type to limit the precision and avoid the exception. This approach can be useful if the LINQ/ESQL query has computed/calculated columns which will store up to 38 precision in Oracle, which cannot be represented as .NET decimal unless the value is casted. 8. Oracle Database treats NULLs and empty strings the same. When executing string related operations on NULLS or empty strings, the result will be NULL. When comparing strings with NULLs, use the equals operator (i.e. "x == NULL") in the LINQ query, which will in turn use the "IS NULL" condition in the generated SQL that will appropriately detect NULL-ness. 9. If an exception message of "The store provider factory type 'Oracle.ManagedDataAccess.Client.OracleClientFactory' does not implement the IServiceProvider interface." is encountered when executing an Entity Framework application with ODP.NET, the machine.config requires and entry for ODP.NET under the section. To resolve this issue by adding an entry in the machine.config, reinstall ODAC. 10. Creating a second instance of the context that derives from DbContext within an application and executing methods within the scope of that context that result in an interaction with the database may result in unexpected recreation of the database objects if the DropCreateDatabaseAlways database initializer is used. More Informations: https://entityframework.codeplex.com/workitem/2362 Known Workarounds: - Use a different database initializer, - Use an operating system authenticated user for the connection, or - Include "Persist Security Info=true" in the connection string (Warning: Turning on "Persist Security Info" will cause the password to remain as part of the connection string).