Added methods to query and post strongly typed points using attributes (#99)

* Added methods to query and post strongly typed points using attributes

* Extend readme with further property types

Co-authored-by: Titusz Ban <titusz.ban@trayport.com>

Author: mvadu

CHANGELOG.md

@@ -1,3 +1,9 @@
+## v0.21.0 [08/25/2020]
+
+### Release Notes
+This version introduces methods to query and post strongly typed points using attributes. Thanks to @tituszban for adding the attribute support. Refer to [Readme.md](https://github.com/AdysTech/InfluxDB.Client.Net/blob/master/README.md) for examples. 
+
+
 ## v0.20.0 [08/11/2020]
 
 ### Release Notes
@@ -268,4 +274,4 @@ Added the functionality to query for existing data from InfluxDB. Also unknown l
 
 ### Bugfixes
 
-- [#3](https://github.com/AdysTech/InfluxDB.Client.Net/pull/3): Double to str conversion fix, Thanks to @spamik
+- [#3](https://github.com/AdysTech/InfluxDB.Client.Net/pull/3): Double to str conversion fix, Thanks to @spamik

README.md

@@ -93,6 +93,62 @@ var r = await client.PostPointAsync(dbName, valMixed);
 
 A collection of points can be posted using `await client.PostPointsAsync (dbName, points)`, where `points` can be collection of different types of `InfluxDatapoint`
 
+#### Writing strongly typed data points to DB
+
+```Csharp
+class YourPoint
+{
+    [InfluxDBMeasurementName]
+    public string Measurement { get; set; }
+
+    [InfluxDBTime]
+    public DateTime Time { get; set; }
+
+    [InfluxDBPrecision]
+    public TimePrecision Precision { get; set; }
+
+    [InfluxDBRetentionPolicy]
+    public InfluxRetentionPolicy Retention { get; set; }
+
+    [InfluxDBField("StringFieldName")]
+    public string StringFieldProperty { get; set; }
+
+    [InfluxDBField("IntFieldName")]
+    public int IntFieldProperty { get; set; }
+
+    [InfluxDBField("BoolFieldName")]
+    public bool BoolFieldProperty { get; set; }
+
+    [InfluxDBField("DoubleFieldName")]
+    public double DoubleFieldProperty { get; set; }
+
+    [InfluxDBTag("TagName")]
+    public string TagProperty { get; set; }
+
+}
+
+var point = new YourPoint
+{
+    Time = DateTime.UtcNow,
+    Measurement = measurementName,
+    Precision = TimePrecision.Seconds,
+    StringFieldProperty = "FieldValue",
+    IntFieldProperty = 42,
+    BoolFieldProperty = true,
+    DoubleFieldProperty = 3.1415,
+    TagProperty = "TagValue",
+    Retention = new InfluxRetentionPolicy() { Name = "Test2" };
+};
+
+var r = await client.PostPointAsync(dbName, point);
+```
+
+This supports all types `InfluxValueField` supports. Additionally it supports tags other than strings, as long as they can be converted to string.
+
+The parameter that has `InfluxDBRetentionPolicy` applied to it can be an `IInfluxRetentionPolicy` alternatively it will be treated as a string and will be used as the name of the retention policy.
+
+A collection of points can be posted using `await client.PostPointsAsync<T>(dbName, points)`, where `points` can be collection of arbitrary type `T` with appropriate attributes
+
 #### Query for data points
 
 ```Csharp
@@ -107,6 +163,18 @@ Second example above will provide multiple series objects, and allows to get dat
 
 The last example above makes InfluxDB to split the selected points (100 limited by `limit` clause) to multiple series, each having 10 points as given by `chunk` size.
 
+
+#### Query for strongly typed data points
+
+```Csharp
+var r = await client.QueryMultiSeriesAsync<YourPoint>(dbName, $"select * from {measurementName}");
+```
+
+`QueryMultiSeriesAsync<T>` method returns `List<InfluxSeries<T>>`, `InfluxSeries<T>` behaves similar to `InfluxSeries` except Entries are not dynamic but strongly typed as T. It uses the same attributes as used for writing the points to match the fields and tags to the matching properties. If a matching property can't be found, the field is discarded. If a property doesn't have a matching field, it's left empty.
+
+It supports multiple chuncks similarly to `QueryMultiSeriesAsync`.
+
+
 #### Retention Policies
 
 This library uses a cutsom .Net object to represent the Influx Retention Policy. The `Duration` concept is nicely wraped in `TimeSpan`, so it can be easily manipulated using .Net code. It also supports `ShardDuration` concept introduced in recent versions of InfluxDB.

src/AdysTech.InfluxDB.Client.Net.Core.csproj

@@ -6,7 +6,7 @@
     <Product>AdysTech.InfluxDB.Client.Net</Product>
     <Company>AdysTech</Company>
     <Authors>AdysTech;mvadu</Authors>
-    <Version>0.20.0.0</Version>
+    <Version>0.21.0.0</Version>
     <PackageId>AdysTech.InfluxDB.Client.Net.Core</PackageId>
     <Copyright>© AdysTech 2016-2020</Copyright>
     <PackageProjectUrl>https://github.com/AdysTech/InfluxDB.Client.Net</PackageProjectUrl>
@@ -31,8 +31,8 @@
       11. Drop databases, measurements or points
       12. Get series count or points count for a measurement
     </PackageReleaseNotes>
-    <AssemblyVersion>0.20.0.0</AssemblyVersion>
-    <FileVersion>0.20.0.0</FileVersion>
+    <AssemblyVersion>0.21.0.0</AssemblyVersion>
+    <FileVersion>0.21.0.0</FileVersion>
     <PackageTags>InfluxDB Influx TSDB TimeSeries InfluxData Chunking retention RetentionPolicy</PackageTags>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
   </PropertyGroup>

src/Attributes/InfluxDBField.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace AdysTech.InfluxDB.Client.Net
+{
+   [AttributeUsage(AttributeTargets.Property, Inherited = true)]
+   public class InfluxDBField : Attribute
+   {
+      public readonly string Name;
+      public InfluxDBField(string name)
+      {
+         Name = name;
+      }
+   }
+}

src/Attributes/InfluxDBMeasurementName.cs

@@ -0,0 +1,7 @@
+using System;
+
+namespace AdysTech.InfluxDB.Client.Net
+{
+   [AttributeUsage(AttributeTargets.Property, Inherited = true)]
+   public class InfluxDBMeasurementName : Attribute { }
+}

src/Attributes/InfluxDBPrecision.cs

@@ -0,0 +1,7 @@
+using System;
+
+namespace AdysTech.InfluxDB.Client.Net
+{
+   [AttributeUsage(AttributeTargets.Property, Inherited = true)]
+   public class InfluxDBPrecision : Attribute { }
+}

src/Attributes/InfluxDBRetentionPolicy.cs

@@ -0,0 +1,7 @@
+using System;
+
+namespace AdysTech.InfluxDB.Client.Net
+{
+    [AttributeUsage(AttributeTargets.Property, Inherited = true)]
+    public class InfluxDBRetentionPolicy : Attribute { }
+}

src/Attributes/InfluxDBTag.cs

@@ -0,0 +1,14 @@
+using System;
+
+namespace AdysTech.InfluxDB.Client.Net
+{
+   [AttributeUsage(AttributeTargets.Property, Inherited = true)]
+   public class InfluxDBTag : Attribute
+   {
+      public readonly string Name;
+      public InfluxDBTag(string name)
+      {
+         Name = name;
+      }
+   }
+}

src/Attributes/InfluxDBTime.cs

@@ -0,0 +1,7 @@
+using System;
+
+namespace AdysTech.InfluxDB.Client.Net
+{
+   [AttributeUsage(AttributeTargets.Property, Inherited = true)]
+   public class InfluxDBTime : Attribute { }
+}