Adds multi-row insert with list of dictionaries (#663)

QueryBuilder.Tests/InsertTests.cs

@@ -1,10 +1,10 @@
+using SqlKata.Compilers;
+using SqlKata.Tests.Infrastructure;
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Dynamic;
 using System.Linq;
-using SqlKata.Compilers;
-using SqlKata.Tests.Infrastructure;
 using Xunit;
 
 namespace SqlKata.Tests
@@ -284,6 +284,45 @@ public void InsertReadOnlyDictionary()
                 c[EngineCodes.Firebird]);
         }
 
+        [Fact]
+        public void InsertDictionaryList()
+        {
+            var expensiveCars = new List<Dictionary<string, object>>
+            {
+                new Dictionary<string, object>
+                {
+                    { "name", "Chiron" },
+                    { "brand", "Bugatti" },
+                    { "year", null },
+                },
+                new Dictionary<string, object>
+                {
+                    { "name", "Huayra" },
+                    { "year", 2012 },
+                    { "brand", "Pagani" },
+                },
+                new Dictionary<string, object>
+                {
+                    { "year", 2009 },
+                    { "brand", "Lamborghini" },
+                    { "name", "Reventon roadster" },
+                },
+            };
+
+            var query = new Query("expensive_cars")
+                .AsInsert(expensiveCars);
+
+            var c = Compile(query);
+
+            Assert.Equal(
+                "INSERT INTO [expensive_cars] ([brand], [name], [year]) VALUES ('Bugatti', 'Chiron', NULL), ('Pagani', 'Huayra', 2012), ('Lamborghini', 'Reventon roadster', 2009)",
+                c[EngineCodes.SqlServer]);
+
+            Assert.Equal(
+                "INSERT INTO \"EXPENSIVE_CARS\" (\"BRAND\", \"NAME\", \"YEAR\") SELECT 'Bugatti', 'Chiron', NULL FROM RDB$DATABASE UNION ALL SELECT 'Pagani', 'Huayra', 2012 FROM RDB$DATABASE UNION ALL SELECT 'Lamborghini', 'Reventon roadster', 2009 FROM RDB$DATABASE",
+                c[EngineCodes.Firebird]);
+        }
+
         [Fact]
         public void InsertExpandoObject()
         {

QueryBuilder/Query.Insert.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Reflection;
 
 namespace SqlKata
 {
@@ -97,6 +96,47 @@ public Query AsInsert(IEnumerable<string> columns, IEnumerable<IEnumerable<objec
             return this;
         }
 
+        public Query AsInsert(IEnumerable<IEnumerable<KeyValuePair<string, object>>> values)
+        {
+            if (values == null || !values.Any())
+            {
+                throw new InvalidOperationException($"{values} argument cannot be null or empty");
+            }
+
+            var columnsList = values.First().Select(x => x.Key).OrderBy(x => x).ToList();
+            if (!columnsList.Any())
+            {
+                throw new InvalidOperationException($"Elements in {values} argument cannot be empty");
+            }
+
+            var rowsValuesList = new List<List<object>>();
+
+            foreach (var rowValues in values)
+            {
+                int rowValuesCount = rowValues.Count();
+                if (rowValuesCount != columnsList.Count())
+                {
+                    throw new InvalidOperationException($"Not all elements in {values} contain the same columns.");
+                }
+
+                var valuesList = new List<object>();
+                var sortedRowValuesList = rowValues.OrderBy(x => x.Key).ToList();
+                for (int i = 0; i < rowValuesCount; i++)
+                {
+                    if (columnsList[i] != sortedRowValuesList[i].Key)
+                    {
+                        throw new InvalidOperationException($"Not all elements in {values} contain the same columns.");
+                    }
+
+                    valuesList.Add(sortedRowValuesList[i].Value);
+                }
+
+                rowsValuesList.Add(valuesList);
+            }
+
+            return AsInsert(columnsList, rowsValuesList);
+        }
+
         /// <summary>
         /// Produces insert from subquery
         /// </summary>