Adding the SqlJson type

src/Microsoft.Data.SqlClient/netcore/src/Microsoft.Data.SqlClient.csproj

@@ -615,6 +615,9 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlTypes\SqlTypeWorkarounds.cs">
       <Link>Microsoft\Data\SqlTypes\SqlTypeWorkarounds.cs</Link>
     </Compile>
+    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlTypes\SqlJson.cs">
+      <Link>Microsoft\Data\SqlTypes\SqlJson.cs</Link>
+    </Compile>
     <Compile Include="$(CommonSourceRoot)Resources\ResCategoryAttribute.cs">
       <Link>Resources\ResCategoryAttribute.cs</Link>
     </Compile>

src/Microsoft.Data.SqlClient/netfx/src/Microsoft.Data.SqlClient.csproj

@@ -636,6 +636,9 @@
     <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlTypes\SqlTypeWorkarounds.cs">
       <Link>Microsoft\Data\SqlTypes\SqlTypeWorkarounds.cs</Link>
     </Compile>
+    <Compile Include="$(CommonSourceRoot)Microsoft\Data\SqlTypes\SqlJson.cs">
+      <Link>Microsoft\Data\SqlTypes\SqlJson.cs</Link>
+    </Compile>
     <Compile Include="$(CommonSourceRoot)Resources\ResCategoryAttribute.cs">
       <Link>Resources\ResCategoryAttribute.cs</Link>
     </Compile>

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlTypes/SqlJson.cs

@@ -0,0 +1,120 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+
+using System.Data.SqlTypes;
+using System.Text;
+using System.Text.Json;
+
+#nullable enable
+
+namespace Microsoft.Data.SqlTypes
+{
+    /// <summary>
+    /// Represents the Json Data type in SQL Server.
+    /// </summary>
+    public class SqlJson : INullable
+    {
+
+        /// <summary>
+        /// True if null.
+        /// </summary>
+        private bool _isNull;         
+
+        private readonly JsonDocument? _jsonDocument;
+
+        private readonly string? _jsonString;
+
+        /// <summary>
+        /// Parameterless constructor. Initializes a new instance of the SqlJson class which 
+        /// represents a null JSON value.
+        /// </summary>
+        public SqlJson()
+        {
+            SetNull();
+        }
+
+        /// <summary>
+        /// Takes a <see cref="string"/> as input and initializes a new instance of the SqlJson class.
+        /// </summary>
+        /// <param name="jsonString"></param>
+        public SqlJson(string? jsonString) 
+        {
+            if (jsonString == null)
+            {
+                SetNull();
+            }
+            else
+            {
+                // TODO: We need to validate the Json before storing it.
+                ValidateJson(jsonString);
+                _jsonString = jsonString;
+            }
+        }
+
+        /// <summary>
+        /// Takes a <see cref="JsonDocument"/> as input and initializes a new instance of the SqlJson class.
+        /// </summary>
+        /// <param name="jsonDoc"></param>
+        public SqlJson(JsonDocument? jsonDoc) 
+        {
+            if (jsonDoc == null)
+            {
+                SetNull();
+            }
+            else
+            {
+                _jsonString = jsonDoc.RootElement.GetRawText();
+            }
+        }
+
+        /// <inheritdoc/>
+        public bool IsNull => _isNull;
+
+        /// <summary>
+        /// Represents a null instance of the <see cref="SqlJson"/> type.
+        /// </summary>
+        public static SqlJson Null => new();
+
+        /// <summary>
+        /// Gets the string representation of the Json content of this <see cref="SqlJson" /> instance.
+        /// </summary>
+        public string Value 
+        { 
+            get
+            {
+                if (IsNull)
+                {
+                    throw new SqlNullValueException();
+                }
+                else
+                {
+                    return _jsonString!;
+                }
+            }
+        }
+
+        private void SetNull()
+        {
+            _isNull = true;
+        }
+
+        static void ValidateJson(string jsonString)
+        {
+            // Convert the JSON string to a UTF-8 byte array
+            byte[] jsonBytes = Encoding.UTF8.GetBytes(jsonString);
+
+            // Create a Utf8JsonReader instance
+            var reader = new Utf8JsonReader(jsonBytes, isFinalBlock: true, state: default);
+
+            // Read through the JSON data
+            while (reader.Read())
+            {
+                // The Read method advances the reader to the next token
+                // If the JSON is invalid, an exception will be thrown
+            }
+            // If we reach here, the JSON is valid
+        }
+    }
+}