From 5060171fb12e7bc68b0435c1f84699e36ce083ad Mon Sep 17 00:00:00 2001
From: opejanovic <opejanovic@gmail.com>
Date: Thu, 7 May 2020 15:41:07 +0200
Subject: [PATCH] I modyfied method Get<T> to be able to read parameters before
 execution. This is really handy for logging parameters before execution.

---
 src/Dapper.Oracle/OracleDynamicParameters.cs        | 13 ++++++++++++-
 .../OracleDynamicParameterTests.cs                  |  8 ++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/Dapper.Oracle/OracleDynamicParameters.cs b/src/Dapper.Oracle/OracleDynamicParameters.cs
index 67dea0b..f113246 100644
--- a/src/Dapper.Oracle/OracleDynamicParameters.cs
+++ b/src/Dapper.Oracle/OracleDynamicParameters.cs
@@ -157,7 +157,18 @@ public IEnumerable<string> ParameterNames
         /// <returns>The value, note DBNull.Value is not returned, instead the value is returned as null</returns>
         public T Get<T>(string name)
         {
-            var val = Parameters[Clean(name)].AttachedParam.Value;
+            var paramInfo = Parameters[Clean(name)];
+            var attachedParam = paramInfo.AttachedParam;
+            object val = attachedParam == null ? paramInfo.Value : attachedParam.Value;
+            if (val == DBNull.Value)
+            {
+                if (default(T) != null)
+                {
+                    throw new ApplicationException("Attempting to cast a DBNull to a non nullable type! Note that out/return parameters will not have updated values until the data stream completes (after the 'foreach' for Query(..., buffered: false), or after the GridReader has been disposed for QueryMultiple)");
+                }
+                return default(T);
+            }
+            
             return OracleValueConverter.Convert<T>(val);
         }
 
diff --git a/src/Tests.Dapper.Oracle/OracleDynamicParameterTests.cs b/src/Tests.Dapper.Oracle/OracleDynamicParameterTests.cs
index 75cc54d..7fde200 100644
--- a/src/Tests.Dapper.Oracle/OracleDynamicParameterTests.cs
+++ b/src/Tests.Dapper.Oracle/OracleDynamicParameterTests.cs
@@ -152,5 +152,13 @@ public void GetParameter_DoesNotReturnNull(IDbCommand cmd)
             param.Value.Should().Be("Bar");
             param.ArrayBindSize.Should().BeSameAs(bindSizeArray);
         }
+
+        [Fact]
+        public void GetParameterValue()
+        {
+            testObject.Add("Foo", "Bar", OracleMappingType.Varchar2);
+
+            testObject.Get<string>("Foo").Should().Be("Bar");
+        }
     }
 }