test

ConsoleApp1/ORM/BulkQuery.cs

@@ -1,7 +1,7 @@
-using System;
 using System.Collections;
 using System.Collections.Generic;
 using System.Data.Common;
+using System.Diagnostics;
 using System.Linq;
 using System.Text;
 using ConsoleApp1.Model;
@@ -13,38 +13,14 @@ namespace ConsoleApp1.ORM
         public static void BulkInsert<TEntity>(IEnumerable<TEntity> entries)
         {
             var entityType = typeof(TEntity);
-            var properties = entityType.GetProperties().Select(p => p.Name);
-            BuildBulkInsertQuery(entityType.Name, properties, entries);
+            var properties = entityType.GetProperties()
+                .Select(p => p.Name)
+                .ToArray();
+            //ExecuteBulkInsertInBatches(entityType.Name, properties, entries);
+            ExecuteBulkInsert(entityType.Name, properties, entries);
         }
 
-        private static void GetParametersValues(string tableName, IEnumerable<string> propertyNames, IEnumerable entries)
-        {
-            static object GetPropertyValue(object o, string propertyName)
-            {
-                //Debug.Assert(propertyName != null, nameof(propertyName) + " != null");
-                var type = o.GetType();
-                var property = type.GetProperty(propertyName);
-                //Debug.Assert(property != null, nameof(property) + " != null");
-                var propertyValue = property?.GetValue(o);
-                return propertyValue;
-            }
-            
-            var fields = propertyNames as string[] ?? propertyNames.ToArray();
-            var i = 0;
-            foreach (var entry in entries)
-            {
-                ++i;
-                Console.WriteLine($"Entry number {i}");
-                foreach (var propertyName in fields)
-                {
-                    var propertyValue = GetPropertyValue(entry, propertyName);
-                    Console.WriteLine($"Property name={propertyName}, value={propertyValue}");
-                }
-                Console.WriteLine();
-            }
-        }
-
-        private static void BuildBulkInsertQuery(string tableName,
+        private static void ExecuteBulkInsertInBatches(string tableName,
             IEnumerable<string> propertyNames,
             IEnumerable entries, 
             int maxBatchSize = 5)
@@ -107,67 +83,55 @@ namespace ConsoleApp1.ORM
                 cmd.ExecuteNonQuery();
             }
         }
-        
-        public static void BulkInsert1(IEnumerable<Person> persons)
+
+        private static void ExecuteBulkInsert(string tableName,
+            IReadOnlyCollection<string> columns,
+            IEnumerable entries)
         {
             using var session = NHibernateHelper.OpenSession();
-            var cmd = session.Connection.CreateCommand();
-
-            var queryString = "INSERT INTO Person (Id, FirstName, LastName) VALUES\n";
-            var sb = new StringBuilder();
-
-            var batchSize = 0;
-            var p = 1; //the current paramter name (i.e. "@p1") we're going to use
-
-            DbParameter CreateDbParameter(object value)
+            var queryString = BuildBulkInsertQueryString(tableName, columns, entries);
+            var query = session.CreateSQLQuery(queryString);
+            
+            static object GetPropertyValue(object o, string propertyName) => o.GetType().GetProperty(propertyName)?.GetValue(o);
+            
+            var parameterIndex = 0;
+            foreach (var entry in entries)
             {
-                var pm = cmd.CreateParameter();
-                pm.Value = value;
-                return pm;
-            }
-
-            foreach (var person in persons)
-            {
-                //Build the names of the parameters
-                var pId = $"@p{p}";   //the "Id" parameter name (i.e. "p1")
-                var pFirstName = $"@p{p + 1}";
-                var pLastName = $"@p{p + 2}";
-                p += 3;
-                
-                //Build a single "(p1, p2)" row
-                var row = $"({pId}, {pFirstName}, {pLastName})"; //a single values tuple
-                
-                //Add the row to our running SQL batch
-                if (batchSize > 0) sb.AppendLine(",");
-                sb.Append(row);
-                batchSize += 1;
-                
-                // Add the parameter values for this row
-                cmd.Parameters.AddRange(new[] {
-                    CreateDbParameter(person.Id),
-                    CreateDbParameter(person.FirstName),
-                    CreateDbParameter(person.LastName)
-                });
-                
-                if (batchSize >= 5)
+                foreach (var column in columns)
                 {
-                    var queryStringComplete = queryString + sb;
-                    cmd.CommandText = queryStringComplete;
-                    cmd.ExecuteNonQuery();
-                    cmd.Parameters.Clear();
-                    sb.Clear();
-                    batchSize = 0;
-                    p = 1;
+                    var value = GetPropertyValue(entry, column);
+                    query.SetParameter(parameterIndex, value);
+                    parameterIndex++;
                 }
             }
-            
-            //handle the last few stragglers
-            if (batchSize > 0)
+
+            query.ExecuteUpdate();
+        }
+
+        private static string BuildBulkInsertQueryString(string tableName,
+            IReadOnlyCollection<string> columns,
+            IEnumerable entries)
+        {
+            var queryString = $"INSERT INTO {tableName} ({string.Join(',', columns)}) VALUES";
+            var sb = new StringBuilder(queryString).AppendLine();
+            var e = entries.GetEnumerator();
+            for (e.MoveNext();;)
             {
-                var queryStringComplete = queryString + sb;
-                cmd.CommandText = queryStringComplete;
-                cmd.ExecuteNonQuery();
+                sb.Append("(");
+                for (var col = 0; col < columns.Count; col++)
+                {
+                    sb.Append($"?");
+                    if (col < columns.Count - 1) sb.Append(",");
+                }
+
+                if (!e.MoveNext())
+                {
+                    sb.Append(");");
+                    break;
+                }
+                sb.AppendLine("),");
             }
+            return sb.ToString();
         }
     }
 }

ConsoleApp1/Repository/PersonRepositoryTest.cs

@@ -72,14 +72,16 @@ namespace ConsoleApp1.Repository
         [Test]
         public void TestBulkInsert()
         {
-            static IEnumerable<Person> GeneratePersons(int num = 3)
+            static Person[] GeneratePersons(int num = 3)
             {
                 var ret = new Person[num];
                 for (var ii = 0; ii < num; ii++) ret[ii] = new Person {Id = Guid.NewGuid(), FirstName = "bac", LastName = "fif"};
                 return ret;
             }
-            
-            _personRepo.Save(GeneratePersons(10));
+
+            var persons = GeneratePersons(10000);
+            _personRepo.Save(persons);
+            Assert.AreEqual(10000, _personRepo.RowCount());
         }
 
         [TearDown]