Please set "ColumnTypeCasingConventionCompatibility = false" before the first usage of the context (e.g.: in a static constructor of a partial class) or in *.config:
<configuration>
<configSections>
<section name="Devart.Data.Oracle.Entity" type="Devart.Data.Oracle.Entity.Configuration.OracleEntityProviderConfigurationSection,
Devart.Data.Oracle.Entity, Version=7.2.96.0, Culture=neutral,
PublicKeyToken=09af7300eec23701" />
</configSections>
<Devart.Data.Oracle.Entity xmlns="http://devart.com/schemas/Devart.Data.Oracle.Entity/1.0">
<CodeFirstOptions ColumnTypeCasingConventionCompatibility="false"/>
</Devart.Data.Oracle.Entity>
</configuration>
For more information, refer to http://www.devart.com/dotconnect/oracle/docs/?CodeFirstOptions.html.