diff --git a/table.lib.tests/SqlInsertTests.cs b/table.lib.tests/SqlInsertTests.cs
index d46334e..e2fdac6 100644
--- a/table.lib.tests/SqlInsertTests.cs
+++ b/table.lib.tests/SqlInsertTests.cs
@@ -1,4 +1,8 @@
+using Dapper;
 using System;
+using System.Collections.Generic;
+using System.Data.SqlClient;
+using System.Linq;
 using table.runner;
 
 namespace table.lib.tests
@@ -31,7 +35,33 @@ public void TestNullGeneration()
             var lines = s.Split(Environment.NewLine);
             Assert.Multiple(() =>
             {
-                Assert.That(lines[0], Is.EqualTo("INSERT INTO TestClass (Field1,Field2,Field3,Field4,Field5,Field6) VALUES (321121,NULL,2121.32,1,'1970-01-01',34.43);"));
+                Assert.That(lines[0], Is.EqualTo("INSERT INTO TestClass (Field1,Field2,Field3,Field4,Field5,Field6) VALUES (NULL,NULL,NULL,NULL,NULL,NULL);"));
+            });
+        }
+
+        [Test]
+        public void TestNullFromDBGeneration()
+        {
+            IEnumerable<IDictionary<string, object>> table;
+            using (var connection = new SqlConnection(@"Data Source=DESKTOP-TTUSQLJ\SQLEXPRESS;Initial Catalog=store;Integrated Security=True"))
+            {
+                connection.Open();
+                const string data = @"
+SELECT PhoneNumber, LockoutEnd
+  FROM [store].[dbo].[AspNetUsers]
+";
+                table = connection.Query(data) as IEnumerable<IDictionary<string, object>>;
+            }
+
+            var enumerable = table as IDictionary<string, object>[] ??
+                             (table ?? throw new InvalidOperationException()).ToArray();
+
+
+            var s = DbTable.Add(enumerable).ToSqlInsertString();
+            var lines = s.Split(Environment.NewLine);
+            Assert.Multiple(() =>
+            {
+                Assert.That(lines[0], Is.EqualTo("INSERT INTO Table1 (PhoneNumber,LockoutEnd) VALUES (NULL,NULL);"));
             });
         }
     }
diff --git a/table.lib/DbTable.cs b/table.lib/DbTable.cs
index 3c3a511..3942b43 100644
--- a/table.lib/DbTable.cs
+++ b/table.lib/DbTable.cs
@@ -238,7 +238,7 @@ public string ToSqlInsertString()
                         DateTime time => "'" + time.ToString("yyyy-MM-dd") + "'",
                         decimal value1 => value1.ToString("#0.0###"),
                         double value1 => value1.ToString("#0.0###"),
-                        _ => (obj != null ? obj.ToString().ToSql() : "")
+                        _ => (obj != null ? obj.ToString().ToSql() : "NULL")
                     };
                     s += $"{p},";
                 }
diff --git a/table.lib/table.lib.csproj b/table.lib/table.lib.csproj
index 4c3efc4..cbf5b10 100644
--- a/table.lib/table.lib.csproj
+++ b/table.lib/table.lib.csproj
@@ -3,17 +3,17 @@
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
     <RootNamespace>table.lib</RootNamespace>
-    <Version>1.12.0</Version>
+    <Version>1.13.0</Version>
     <Copyright>Jordi Corbilla</Copyright>
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <RepositoryUrl>https://github.com/JordiCorbilla/table.lib</RepositoryUrl>
-    <PackageReleaseNotes>v1.12
+    <PackageReleaseNotes>v1.13
 - Upgrade to .net 6</PackageReleaseNotes>
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
     <Description>Simple c# (.NET 6) table library that renders any List&lt;T&gt; or Dictionary&lt;TV, T&gt; into a nicely formatted markdown, csv, html, specflow or console table, allowing for extra formats. It also supports dynamic returns from Dapper as IEnumerable&lt;IDictionary&lt;string, object&gt;&gt; via DBTable object.</Description>
-    <AssemblyVersion>1.12.0.0</AssemblyVersion>
-    <FileVersion>1.12.0.0</FileVersion>
+    <AssemblyVersion>1.13.0.0</AssemblyVersion>
+    <FileVersion>1.13.0.0</FileVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/table.runner/Samples.cs b/table.runner/Samples.cs
index 7426cf4..6a2f3d2 100644
--- a/table.runner/Samples.cs
+++ b/table.runner/Samples.cs
@@ -80,8 +80,8 @@ public static List<TestClass> GetNullOutput()
             {
                 new TestClass
                 {
-                    Field1 = 321121, Field2 = null, Field3 = 2121.32m, Field4 = true,
-                    Field5 = new DateTime(1970, 1, 1), Field6 = 34.43
+                    Field1 = null, Field2 = null, Field3 = null, Field4 = null,
+                    Field5 = null, Field6 = null
                 }
             };
             return list;
diff --git a/table.runner/TestClass.cs b/table.runner/TestClass.cs
index b58e49d..5710781 100644
--- a/table.runner/TestClass.cs
+++ b/table.runner/TestClass.cs
@@ -26,11 +26,11 @@ namespace table.runner
 {
     public class TestClass
     {
-        public int Field1 { get; set; }
-        public string Field2 { get; set; }
-        public decimal Field3 { get; set; }
-        public bool Field4 { get; set; }
-        public DateTime Field5 { get; set; }
-        public double Field6 { get; set; }
+        public int? Field1 { get; set; }
+        public string? Field2 { get; set; }
+        public decimal? Field3 { get; set; }
+        public bool? Field4 { get; set; }
+        public DateTime? Field5 { get; set; }
+        public double? Field6 { get; set; }
     }
 }
\ No newline at end of file