La columna de la base de datos de Oracle para un .Net Int32 debería ser:NUMBER(9, 0)
Según la Tabla de conversión :
+------------------------------+------------------+-----------------+
| Oracle Type | Default EDM Type | Custom EDM Type |
+------------------------------+------------------+-----------------+
| Number(1,0) | Int16 | bool |
| Number(2,0) to Number(3,0) | Int16 | byte |
| Number(4,0) | Int16 | Int16 |
| Number(5,0) | Int16 | Int32 |
| Number(6,0) to Number(9,0) | Int32 | Int32 |
| Number(10,0) | Int32 | Int64 |
| Number(11,0) to Number(18,0) | Int64 | Int64 |
| Number(19,0) | Int64 | Decimal |
+------------------------------+------------------+-----------------+
Editar:
Encontré una manera de forzar el Number(2,0) para ser traducido a un byte en App.Config para el enfoque de base de datos primero :
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<connectionStrings>
</connectionStrings>
<oracle.dataaccess.client>
<settings>
<add name="bool" value="edmmapping number(1,0)" />
<add name="byte" value="edmmapping number(3,0)" />
<add name="int16" value="edmmapping number(4,0)" />
REF:https://docs.oracle.com/database/121 /ODPNT/entityDataTypeMapping.htm#ODPNT8300
