Merge pull request #219 from smoothdeveloper/expose-data-columns

Expose DataColumn properties on DataColumnCollection

Author: dmitry-a-morozov

docs/content/data modification.fsx

@@ -29,7 +29,7 @@ do
         INSERT INTO Sales.CurrencyRate 
         VALUES (@currencyRateDate, @fromCurrencyCode, @toCurrencyCode, 
                 @averageRate, @endOfDayRate, DEFAULT) 
-    ", connectionString>()
+    ", connectionString>(connectionString)
 
     let recordsInserted = 
         cmd.Execute(
@@ -63,7 +63,7 @@ let businessEntityID, jobTitle, hireDate =
             HumanResources.Employee 
         WHERE 
             BusinessEntityID = @id
-        ", connectionString, ResultType.Tuples, SingleRow = true>()
+        ", connectionString, ResultType.Tuples, SingleRow = true>(connectionString))
 
     jamesKramerId |> cmd.Execute |> Option.get
 
@@ -72,7 +72,7 @@ assert("Production Technician - WC60" = jobTitle)
 let newJobTitle = "Uber " + jobTitle
 
 let recordsAffrected = 
-    use updatedJobTitle = new AdventureWorks.HumanResources.uspUpdateEmployeeHireInfo()
+    use updatedJobTitle = new AdventureWorks.HumanResources.uspUpdateEmployeeHireInfo(connectionString))
     updatedJobTitle.Execute(
         businessEntityID, 
         newJobTitle, 
@@ -88,7 +88,7 @@ assert(recordsAffrected = 1)
 let updatedJobTitle = 
     // Static Create factory method provides better IntelliSense than ctor.
     // See https://github.com/Microsoft/visualfsharp/issues/449
-    use cmd = new AdventureWorks.dbo.ufnGetContactInformation()
+    use cmd = new AdventureWorks.dbo.ufnGetContactInformation(connectionString)
 
     //Use ExecuteSingle if you're sure it return 0 or 1 rows.
     let result = cmd.ExecuteSingle(PersonID = jamesKramerId) 
@@ -133,6 +133,13 @@ The IntelliSense experience is left a little clunky to retain legacy `DataRow` t
 let firstRow = currencyRates.Rows.[0]
 firstRow.AverageRate
 
+(**
+It is possible to get a reference to the DataColumn object
+*)
+
+let averageRateColumn = currencyRates.Columns.AverageRate
+
+
 (**
 The `AddRow` method adds a new row to a table. 
 
@@ -210,7 +217,7 @@ do
         WHERE FromCurrencyCode = @from
             AND ToCurrencyCode = @to
             AND CurrencyRateDate > @date
-        ", connectionString, ResultType.DataReader>()
+        ", connectionString, ResultType.DataReader>(connectionString)
     //ResultType.DataReader !!!
     let currencyRates = new AdventureWorks.Sales.Tables.CurrencyRate()
     //load data into data table
@@ -347,7 +354,7 @@ do
         WHERE FromCurrencyCode = @from
             AND ToCurrencyCode = @to
             AND CurrencyRateDate > @date
-        ", connectionString, ResultType.DataTable>()
+        ", connectionString, ResultType.DataTable>(connectionString)
     //ResultType.DataTable !!!
     let currencyRates = cmd.Execute("USD", "GBP", DateTime(2014, 1, 1)) 
 

src/SqlClient.Tests/DataTablesTests.fs

@@ -17,7 +17,7 @@ type ProductCostHistory = AdventureWorks.Production.Tables.ProductCostHistory
 
 type GetRowCount = SqlCommandProvider<"SELECT COUNT(*) FROM HumanResources.Shift", ConnectionStrings.AdventureWorksNamed, SingleRow = true>
 type GetShiftTableData = SqlCommandProvider<"SELECT * FROM HumanResources.Shift", ConnectionStrings.AdventureWorksNamed, ResultType.DataReader>
-type GetArbitraryDataAsDataTable = SqlCommandProvider<"select 1 a, 2 b, 3 c", ConnectionStrings.AdventureWorksNamed, ResultType.DataTable>
+type GetArbitraryDataAsDataTable = SqlCommandProvider<"select 1 a, 2 b, 3 c, cast(null as int) d", ConnectionStrings.AdventureWorksNamed, ResultType.DataTable>
 type DataTablesTests() = 
 
     do
@@ -281,3 +281,42 @@ type DataTablesTests() =
         Assert.Equal(1, t.Rows.[0].a)
         Assert.Equal(2, t.Rows.[0].b)
         Assert.Equal(3, t.Rows.[0].c)
+        Assert.Equal(None, t.Rows.[0].d)
+
+    [<Fact>]
+    member __.``Can use datacolumns and access like a normal DataRow`` () =
+        let t = (new GetArbitraryDataAsDataTable()).Execute()
+        let r = t.Rows.[0]
+      
+        Assert.Equal(1, r.[t.Columns.a] :?> int)
+        Assert.Equal(2, r.[t.Columns.b] :?> int)
+        Assert.Equal(3, r.[t.Columns.c] :?> int)
+        // getting value same way as a plain datatable still yields DBNull
+        Assert.Equal(DBNull.Value, r.[t.Columns.d] :?> DBNull)
+
+
+    [<Fact>]
+    member __.``Can use DataColumnCollection`` () =
+
+        let table = (new GetArbitraryDataAsDataTable()).Execute()
+
+        let columnCollection : System.Data.DataColumnCollection =
+            // this is more involved than just doing table.Columns because
+            // DataColumnCollection is a sealed class, and the generative TP
+            // attaches properties to a fake inherited type
+            // In order to get a real DataColumnCollection, just use the table
+            // as a normal DataTable.
+            let table : System.Data.DataTable = table :> _
+            table.Columns
+        Assert.Equal(table.Columns.Count, columnCollection.Count)
+    
+    [<Fact>]
+    member __.``Can use datacolumns on SqlProgrammabilityProvider`` () =
+        let products = AdventureWorks.Production.Tables.Product()
+        
+        let product = products.NewRow()
+        product.Name <- "foo"
+
+        // use as plain DataColumns
+        let name = product.[products.Columns.Name] :?> string
+        Assert.True(product.Name = name)

src/SqlClient/DesignTime.fs

@@ -147,35 +147,82 @@ type DesignTime private() =
             @@> 
         recordType.AddMember ctor
 
-        recordType    
+        recordType
+
+    static member internal GetDataRowPropertyGetterAndSetterCode (column: Column) =
+        let name = column.Name
+        if column.Nullable then
+            let getter = QuotationsFactory.GetBody("GetNullableValueFromDataRow", column.TypeInfo.ClrType, name)
+            let setter = QuotationsFactory.GetBody("SetNullableValueInDataRow", column.TypeInfo.ClrType, name)
+            getter, setter
+        else
+            let getter = QuotationsFactory.GetBody("GetNonNullableValueFromDataRow", column.TypeInfo.ClrType, name)
+            let setter = QuotationsFactory.GetBody("SetNonNullableValueInDataRow", column.TypeInfo.ClrType, name)
+            getter, setter
 
     static member internal GetDataRowType (columns: Column list) = 
         let rowType = ProvidedTypeDefinition("Row", Some typeof<DataRow>)
 
-        columns |> List.mapi( fun i col ->
-            let name = col.Name
-            if name = "" then failwithf "Column #%i doesn't have name. Only columns with names accepted. Use explicit alias." (i + 1)
+        columns |> List.mapi(fun i col ->
+
+            if col.Name = "" then failwithf "Column #%i doesn't have name. Only columns with names accepted. Use explicit alias." (i + 1)
 
             let propertyType = col.ClrTypeConsideringNullable
-            if col.Nullable 
-            then
-                let property = ProvidedProperty(name, propertyType, GetterCode = QuotationsFactory.GetBody("GetNullableValueFromDataRow", col.TypeInfo.ClrType, name))
-                if not col.ReadOnly
-                then property.SetterCode <- QuotationsFactory.GetBody("SetNullableValueInDataRow", col.TypeInfo.ClrType, name)
-                property
-            else
-                let property = ProvidedProperty(name, propertyType, GetterCode = (fun args -> <@@ (%%args.[0] : DataRow).[name] @@>))
-                if not col.ReadOnly
-                then property.SetterCode <- fun args -> <@@ (%%args.[0] : DataRow).[name] <- %%Expr.Coerce(args.[1], typeof<obj>) @@>
-                property
+
+            let getter, setter = DesignTime.GetDataRowPropertyGetterAndSetterCode col
+            let property = ProvidedProperty(col.Name, propertyType, GetterCode = getter)
+
+            if not col.ReadOnly then
+              // only expose a setter if the column is not readonly
+              // note: if this is an issue, we always expose a SetValue method on the typed DataColumn itself
+              property.SetterCode <- setter
+            
+            property
         )
         |> rowType.AddMembers
 
         rowType
 
-    static member internal GetDataTableType dataRowType =
+    static member internal GetDataTableType typeName dataRowType (outputColumns: Column list) =
         let tableType = ProvidedTypeBuilder.MakeGenericType(typedefof<_ DataTable>, [ dataRowType ])
-        let tableProvidedType = ProvidedTypeDefinition("Table", Some tableType)
+        let tableProvidedType = ProvidedTypeDefinition(typeName, Some tableType)
+      
+        let columnsType = ProvidedTypeDefinition("Columns", Some typeof<DataColumnCollection>)
+        
+        let ctor = ProvidedConstructor([])
+        ctor.InvokeCode <- fun args ->
+          <@@
+            ()
+          @@>
+        columnsType.AddMember ctor
+        let columnsProperty = ProvidedProperty("Columns", columnsType)
+        tableProvidedType.AddMember columnsType
+        
+        columnsProperty.GetterCode <-
+            fun args -> 
+                <@@
+                    let table : DataTable<DataRow> = %%args.[0]
+                    table.Columns
+                @@>
+
+        tableProvidedType.AddMember columnsProperty
+      
+        for column in outputColumns do
+            let propertyType = ProvidedTypeDefinition(column.Name, Some typeof<DataColumn>)
+            let property = ProvidedProperty(column.Name, propertyType)
+            
+            property.GetterCode <- 
+                fun args -> 
+                    let columnName = column.Name
+                    <@@ 
+                        let columns : DataColumnCollection = %%args.[0]
+                        let column = columns.[columnName]
+                        column
+                    @@>
+
+            columnsType.AddMember property
+            columnsType.AddMember propertyType
+
         tableProvidedType
 
     static member internal GetOutputTypes (outputColumns: Column list, resultType, rank: ResultRank, hasOutputParameters) =    
@@ -188,7 +235,7 @@ type DesignTime private() =
         elif resultType = ResultType.DataTable 
         then
             let dataRowType = DesignTime.GetDataRowType outputColumns
-            let dataTableType = DesignTime.GetDataTableType dataRowType 
+            let dataTableType = DesignTime.GetDataTableType "Table" dataRowType outputColumns
 
             // add .Row to .Table
             dataTableType.AddMember dataRowType

src/SqlClient/QuotationsFactory.fs

@@ -119,4 +119,10 @@ type QuotationsFactory private() =
     static member GetMapperWithNullsToOptions(nullsToOptions, mapper: obj[] -> obj) = 
         fun values -> 
             nullsToOptions values
-            mapper values
+            mapper values
+
+    static member private GetNonNullableValueFromDataRow<'T>(exprArgs : Expr list, name: string) =
+        <@ (%%exprArgs.[0] : DataRow).[name] @>
+
+    static member private SetNonNullableValueInDataRow<'T>(exprArgs : Expr list, name : string) =
+        <@ (%%exprArgs.[0] : DataRow).[name] <- %%Expr.Coerce(exprArgs.[1], typeof<obj>) @>

src/SqlClient/SqlClientProvider.fs

@@ -304,8 +304,8 @@ type public SqlProgrammabilityProvider(config : TypeProviderConfig) as this =
                             //remove from PK if default value provided by DB on insert.
                         else c
                     )
-                    |> Seq.toArray
-
+                    |> Seq.toList
+                
 
                 //type data row
                 let dataRowType = ProvidedTypeDefinition("Row", Some typeof<DataRow>)
@@ -349,7 +349,7 @@ type public SqlProgrammabilityProvider(config : TypeProviderConfig) as this =
                         dataRowType.AddMember property
 
                 //type data table
-                let dataTableType = ProvidedTypeDefinition(tableName, baseType = Some( typedefof<_ DataTable>.MakeGenericType(dataRowType)))
+                let dataTableType = DesignTime.GetDataTableType tableName dataRowType columns
                 tagProvidedType dataTableType
                 dataTableType.AddMember dataRowType
 
@@ -361,7 +361,7 @@ type public SqlProgrammabilityProvider(config : TypeProviderConfig) as this =
                     ctor.InvokeCode <- fun _ -> 
                         let serializedSchema = 
                             columns 
-                            |> Array.map (fun x ->
+                            |> List.map (fun x ->
                                 let nullable = x.Nullable || x.HasDefaultConstraint
                                 sprintf "%s\t%s\t%b\t%i\t%b\t%b\t%b" 
                                     x.Name x.TypeInfo.ClrTypeFullName nullable x.MaxLength x.ReadOnly x.Identity x.PartOfUniqueKey