Feature, Public API | Enable SqlDataRecord support for TVPs with computed columns

doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml

@@ -1,4 +1,4 @@
-<docs>
+<docs>
   <members name="SqlMetaData">
     <SqlMetaData>
       <summary>
@@ -1490,6 +1490,22 @@
         The <paramref name="value" /> is <see langword="null" />.
       </exception>
     </InferFromValue>
+    <IsComputed>
+      <summary>
+        Indicates if this column is computed by the server.
+      </summary>
+      <value>
+        A <see cref="T:System.Boolean" /> value.
+      </value>
+      <remarks>
+        <para>
+          The default is <see langword="false" />.
+        </para>
+        <para>
+          This property can only be set from an object initializer immediately after construction of the <see cref="T:Microsoft.Data.SqlClient.Server.SqlMetaData" /> instance.
+        </para>
+      </remarks>
+    </IsComputed>
     <IsUniqueKey>
       <summary>
         Indicates if the column in the table-valued parameter is unique.

src/Microsoft.Data.SqlClient/ref/Microsoft.Data.SqlClient.Server.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// 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.
 
@@ -215,6 +215,8 @@ public SqlMetaData(string name, System.Data.SqlDbType dbType, System.Type userDe
     public System.Data.SqlTypes.SqlCompareOptions CompareOptions { get { throw null; } }
     /// <include file='../../../doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml' path='docs/members[@name="SqlMetaData"]/DbType/*' />
     public System.Data.DbType DbType { get { throw null; } }
+    /// <include file='../../../doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml' path='docs/members[@name="SqlMetaData"]/IsComputed/*' />
+    public bool IsComputed { get { throw null; } init { } }
     /// <include file='../../../doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml' path='docs/members[@name="SqlMetaData"]/IsUniqueKey/*' />
     public bool IsUniqueKey { get { throw null; } }
     /// <include file='../../../doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml' path='docs/members[@name="SqlMetaData"]/LocaleId/*' />

src/Microsoft.Data.SqlClient/ref/System.Runtime.CompilerServices.cs

@@ -0,0 +1,18 @@
+// 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.
+
+#if !NET
+
+namespace System.Runtime.CompilerServices;
+
+/// <summary>
+/// Reserved to be used by the compiler for tracking metadata.
+/// This class should not be used by developers in source code.
+/// </summary>
+[System.ComponentModel.EditorBrowsable(System.ComponentModel.EditorBrowsableState.Never)]
+internal static class IsExternalInit
+{
+}
+
+#endif

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/Server/SmiMetaData.cs

@@ -349,6 +349,7 @@ SmiMetaDataPropertyCollection extendedProperties
             ((SmiDefaultFieldsProperty)_extendedProperties[SmiPropertySelector.DefaultFields]).CheckCount(_fieldMetaData.Count);
             ((SmiOrderProperty)_extendedProperties[SmiPropertySelector.SortOrder]).CheckCount(_fieldMetaData.Count);
             ((SmiUniqueKeyProperty)_extendedProperties[SmiPropertySelector.UniqueKey]).CheckCount(_fieldMetaData.Count);
+            ((SmiComputedFieldsProperty)_extendedProperties[SmiPropertySelector.ComputedFields]).CheckCount(_fieldMetaData.Count);
 #endif
         }
 

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/Server/SmiMetaDataProperty.cs

@@ -18,12 +18,13 @@ internal enum SmiPropertySelector
         DefaultFields = 0x0,
         SortOrder = 0x1,
         UniqueKey = 0x2,
+        ComputedFields = 0x3,
     }
 
     // Simple collection for properties.  Could extend to IDictionary support if needed in future.
     internal class SmiMetaDataPropertyCollection
     {
-        private const int SelectorCount = 3;  // number of elements in SmiPropertySelector
+        private const int SelectorCount = 4;  // number of elements in SmiPropertySelector
 
         private readonly SmiMetaDataProperty[] _properties;
         private bool _isReadOnly;
@@ -32,6 +33,7 @@ internal class SmiMetaDataPropertyCollection
         private static readonly SmiDefaultFieldsProperty s_emptyDefaultFields = new SmiDefaultFieldsProperty(new List<bool>());
         private static readonly SmiOrderProperty s_emptySortOrder = new SmiOrderProperty(new List<SmiOrderProperty.SmiColumnOrder>());
         private static readonly SmiUniqueKeyProperty s_emptyUniqueKey = new SmiUniqueKeyProperty(new List<bool>());
+        private static readonly SmiComputedFieldsProperty s_emptyIsComputedField = new SmiComputedFieldsProperty(new List<bool>());
 
         internal static readonly SmiMetaDataPropertyCollection s_emptyInstance = CreateEmptyInstance();
 
@@ -49,6 +51,7 @@ internal SmiMetaDataPropertyCollection()
             _properties[(int)SmiPropertySelector.DefaultFields] = s_emptyDefaultFields;
             _properties[(int)SmiPropertySelector.SortOrder] = s_emptySortOrder;
             _properties[(int)SmiPropertySelector.UniqueKey] = s_emptyUniqueKey;
+            _properties[(int)SmiPropertySelector.ComputedFields] = s_emptyIsComputedField;
         }
 
         internal SmiMetaDataProperty this[SmiPropertySelector key]
@@ -275,4 +278,67 @@ internal override string TraceString()
 
         #endregion
     }
+
+    internal class SmiComputedFieldsProperty : SmiMetaDataProperty
+    {
+        #region private fields
+
+        private readonly IList<bool> _computed;
+
+        #endregion
+
+        #region internal interface
+
+        internal SmiComputedFieldsProperty(IList<bool> computedFields) => _computed = new System.Collections.ObjectModel.ReadOnlyCollection<bool>(computedFields);
+
+        internal bool this[int ordinal]
+        {
+            get
+            {
+                if (_computed.Count <= ordinal)
+                {
+                    return false;
+                }
+                else
+                {
+                    return _computed[ordinal];
+                }
+            }
+        }
+
+        [Conditional("DEBUG")]
+        internal void CheckCount(int countToMatch)
+        {
+            Debug.Assert(0 == _computed.Count || countToMatch == _computed.Count,
+                    "SmiComputedFieldsProperty.CheckCount: ComputedFieldsProperty size (" + _computed.Count +
+                    ") not equal to checked size (" + countToMatch + ")");
+        }
+
+        internal override string TraceString()
+        {
+            string returnValue = "ComputedFields(";
+            bool delimit = false;
+            for (int columnOrd = 0; columnOrd < _computed.Count; columnOrd++)
+            {
+                if (delimit)
+                {
+                    returnValue += ",";
+                }
+                else
+                {
+                    delimit = true;
+                }
+
+                if (_computed[columnOrd])
+                {
+                    returnValue += columnOrd;
+                }
+            }
+            returnValue += ")";
+
+            return returnValue;
+        }
+
+        #endregion
+    }
 }

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/Server/SqlMetaData.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// 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.
 
@@ -505,6 +505,9 @@ public string TypeName
         /// <include file='../../../../../../../doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml' path='docs/members[@name="SqlMetaData"]/UseServerDefault/*' />
         public bool UseServerDefault => _useServerDefault;
 
+        /// <include file='../../../../../../../doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml' path='docs/members[@name="SqlMetaData"]/IsComputed/*' />
+        public bool IsComputed { get; init; }
+
         /// <include file='../../../../../../../doc/snippets/Microsoft.Data.SqlClient.Server/SqlMetaData.xml' path='docs/members[@name="SqlMetaData"]/XmlSchemaCollectionDatabase/*' />
         public string XmlSchemaCollectionDatabase => _xmlSchemaCollectionDatabase;
 

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/SqlParameter.cs

@@ -1334,9 +1334,11 @@ private void GetActualFieldsAndProperties(out List<SmiExtendedMetaData> fields,
                             bool[] keyCols = new bool[fieldCount];
                             bool[] defaultFields = new bool[fieldCount];
                             bool[] sortOrdinalSpecified = new bool[fieldCount];
+                            bool[] computedFields = new bool[fieldCount];
                             int maxSortOrdinal = -1;  // largest sort ordinal seen, used to optimize locating holes in the list
                             bool hasKey = false;
                             bool hasDefault = false;
+                            bool hasComputedFields = false;
                             int sortCount = 0;
                             SmiOrderProperty.SmiColumnOrder[] sort = new SmiOrderProperty.SmiColumnOrder[fieldCount];
                             fields = new List<SmiExtendedMetaData>(fieldCount);
@@ -1356,6 +1358,16 @@ private void GetActualFieldsAndProperties(out List<SmiExtendedMetaData> fields,
                                     hasDefault = true;
                                 }
 
+                                if (colMeta.IsComputed)
+                                {
+                                    // A computed column will always have a default value, so skip writing
+                                    // its values out to the TDS stream.
+                                    defaultFields[i] = true;
+                                    computedFields[i] = true;
+                                    hasDefault = true;
+                                    hasComputedFields = true;
+                                }
+
                                 sort[i]._order = colMeta.SortOrder;
                                 if (SortOrder.Unspecified != colMeta.SortOrder)
                                 {
@@ -1400,6 +1412,14 @@ private void GetActualFieldsAndProperties(out List<SmiExtendedMetaData> fields,
                                 props[SmiPropertySelector.DefaultFields] = new SmiDefaultFieldsProperty(new List<bool>(defaultFields));
                             }
 
+                            if (hasComputedFields)
+                            {
+                                // We've already created props list in default value handling
+                                Debug.Assert(props is not null);
+
+                                props[SmiPropertySelector.ComputedFields] = new SmiComputedFieldsProperty(new List<bool>(computedFields));
+                            }
+
                             if (0 < sortCount)
                             {
                                 // validate monotonically increasing sort order.

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsEnums.cs

@@ -445,6 +445,7 @@ public enum ActiveDirectoryWorkflow : byte
         public const byte TVP_ORDER_UNIQUE_TOKEN = 0x10;
 
         // TvpColumnMetaData flags
+        public const int TVP_COMPUTED_COLUMN = 0x20;
         public const int TVP_DEFAULT_COLUMN = 0x200;
 
         // TVP_ORDER_UNIQUE_TOKEN flags

src/Microsoft.Data.SqlClient/src/Microsoft/Data/SqlClient/TdsParser.cs

@@ -11261,9 +11261,10 @@ private void WriteTvpTypeInfo(SmiExtendedMetaData metaData, TdsParserStateObject
 
                 // TvpColumnMetaData for each column (look for defaults in this loop
                 SmiDefaultFieldsProperty defaults = (SmiDefaultFieldsProperty)metaData.ExtendedProperties[SmiPropertySelector.DefaultFields];
+                SmiComputedFieldsProperty computedFields = (SmiComputedFieldsProperty)metaData.ExtendedProperties[SmiPropertySelector.ComputedFields];
                 for (int i = 0; i < metaData.FieldMetaData.Count; i++)
                 {
-                    WriteTvpColumnMetaData(metaData.FieldMetaData[i], defaults[i], stateObj);
+                    WriteTvpColumnMetaData(metaData.FieldMetaData[i], defaults[i], computedFields[i], stateObj);
                 }
 
                 // optional OrderUnique metadata
@@ -11275,7 +11276,7 @@ private void WriteTvpTypeInfo(SmiExtendedMetaData metaData, TdsParserStateObject
         }
 
         // Write a single TvpColumnMetaData stream to the server
-        private void WriteTvpColumnMetaData(SmiExtendedMetaData md, bool isDefault, TdsParserStateObject stateObj)
+        private void WriteTvpColumnMetaData(SmiExtendedMetaData md, bool isDefault, bool isComputed, TdsParserStateObject stateObj)
         {
             // User Type
             if (SqlDbType.Timestamp == md.SqlDbType)
@@ -11293,6 +11294,10 @@ private void WriteTvpColumnMetaData(SmiExtendedMetaData md, bool isDefault, TdsP
             {
                 status |= TdsEnums.TVP_DEFAULT_COLUMN;
             }
+            if (isComputed)
+            {
+                status |= TdsEnums.TVP_COMPUTED_COLUMN;
+            }
             WriteUnsignedShort(status, stateObj);
 
             // Type info