Removed POSTGRESQL define and added SqlAdapter dictionary to handle variances in DBMSs

Dapper.Contrib/SqlMapperExtensions.cs

-#define POSTGRESQL
-
-using System;
+using System;
 using System.Collections.Generic;
 using System.Data;
 using System.Diagnostics;
@@ -11,6 +9,7 @@
 using System.Reflection.Emit;
 using System.Threading;
 using System.Runtime.CompilerServices;
+using Dapper;
 
 namespace Dapper.Contrib.Extensions
 {
@@ -27,6 +26,11 @@ public interface IProxy
         private static readonly ConcurrentDictionary<RuntimeTypeHandle, string> GetQueries = new ConcurrentDictionary<RuntimeTypeHandle, string>();
         private static readonly ConcurrentDictionary<RuntimeTypeHandle, string> TypeTableName = new ConcurrentDictionary<RuntimeTypeHandle, string>();
 
+		private static readonly Dictionary<string, ISqlAdapter> AdapterDictionary = new Dictionary<string, ISqlAdapter>() {
+																							{"sqlconnection", new SqlServerAdapter()},
+																							{"npgsqlconnection", new PostgresAdapter()}
+																						};
+
         private static IEnumerable<PropertyInfo> KeyPropertiesCache(Type type)
         {
 
@@ -167,60 +171,30 @@ private static string GetTableName(Type type)
 
             var name = GetTableName(type);
 
-            var sb = new StringBuilder(null);
-            sb.AppendFormat("insert into {0} (", name);
+            var sbColumnList = new StringBuilder(null);
 
-            var allProperties = TypePropertiesCache(type);
+			var allProperties = TypePropertiesCache(type);
             var keyProperties = KeyPropertiesCache(type);
             var allPropertiesExceptKey = allProperties.Except(keyProperties);
 
             for (var i = 0; i < allPropertiesExceptKey.Count(); i++)
             {
                 var property = allPropertiesExceptKey.ElementAt(i);
-                sb.Append(property.Name);
+				sbColumnList.Append(property.Name);
                 if (i < allPropertiesExceptKey.Count() - 1)
-                    sb.Append(", ");
+					sbColumnList.Append(", ");
             }
-            sb.Append(") values (");
 
-            for (var i = 0; i < allPropertiesExceptKey.Count(); i++)
+			var sbParameterList = new StringBuilder(null);
+			for (var i = 0; i < allPropertiesExceptKey.Count(); i++)
             {
                 var property = allPropertiesExceptKey.ElementAt(i);
-                sb.AppendFormat("@{0}", property.Name);
+                sbParameterList.AppendFormat("@{0}", property.Name);
                 if (i < allPropertiesExceptKey.Count() - 1)
-                    sb.Append(", ");
+                    sbParameterList.Append(", ");
             }
-			sb.Append(") ");
-			long id = 0;
-#if POSTGRESQL
-			if (keyProperties.Count() > 0)
-			{
-				sb.Append(" RETURNING ");
-				for (var i = 0; i < keyProperties.Count(); i++)
-				{
-					var property = keyProperties.ElementAt(i);
-					sb.Append(property.Name);
-					if (i < keyProperties.Count() - 1)
-						sb.Append(", ");
-				}
-				var r = connection.Query(sb.ToString(), entityToInsert, transaction: transaction, commandTimeout: commandTimeout);
-				// Return the key py assinging the corresponding property in the object - by product is that it supports compound primary keys
-				foreach (var p in keyProperties)
-				{
-					var value = ((IDictionary<string, object>) r.First())[p.Name.ToLower()];
-					p.SetValue(entityToInsert, value, null);
-					if (id == 0)
-						id = Convert.ToInt64(value);
-				}
-			}
-			else
-				connection.Execute(sb.ToString(), entityToInsert, transaction: transaction, commandTimeout: commandTimeout);
-#else
-            connection.Execute(sb.ToString(), entityToInsert, transaction: transaction, commandTimeout: commandTimeout);
-            //NOTE: would prefer to use IDENT_CURRENT('tablename') or IDENT_SCOPE but these are not available on SQLCE
-            var r = connection.Query("select @@IDENTITY id", transaction: transaction, commandTimeout: commandTimeout);
-            id = (int)r.First().id;
-#endif
+			ISqlAdapter adapter = GetFormatter(connection);
+			int id = adapter.Insert(connection, transaction, commandTimeout, name, sbColumnList.ToString(), sbParameterList.ToString(),  keyProperties, entityToInsert);
 			return id;
         }
 
@@ -242,7 +216,7 @@ private static string GetTableName(Type type)
             var type = typeof(T);
 
             var keyProperties = KeyPropertiesCache(type);
-            if (keyProperties.Count() == 0)
+            if (!keyProperties.Any())
                 throw new ArgumentException("Entity must have at least one [Key] property");
 
             var name = GetTableName(type);
@@ -303,8 +277,15 @@ private static string GetTableName(Type type)
             return deleted > 0;
         }
 
+		public static ISqlAdapter GetFormatter(IDbConnection connection)
+		{
+			string name = connection.GetType().Name.ToLower();
+			if (!AdapterDictionary.ContainsKey(name))
+				return new SqlServerAdapter();
+			return AdapterDictionary[name];
+		}
 
-        class ProxyGenerator
+    	class ProxyGenerator
         {
             private static readonly Dictionary<Type, object> TypeCache = new Dictionary<Type, object>();
 
@@ -489,3 +470,53 @@ public WriteAttribute(bool write)
         public bool Write { get; private set; }
 	}
 }
+
+public interface ISqlAdapter
+{
+	int Insert(IDbConnection connection, IDbTransaction transaction, int? commandTimeout, String tableName, string columnList, string parameterList, IEnumerable<PropertyInfo> keyProperties, object entityToInsert);
+}
+
+public class SqlServerAdapter : ISqlAdapter
+{
+	public int Insert(IDbConnection connection, IDbTransaction transaction, int? commandTimeout, String tableName, string columnList, string parameterList, IEnumerable<PropertyInfo> keyProperties, object entityToInsert)
+	{
+		string cmd = String.Format("insert into {0} ({1}) values ({2})", tableName, columnList, parameterList);
+
+		connection.Execute(cmd, entityToInsert, transaction: transaction, commandTimeout: commandTimeout); 
+
+		//NOTE: would prefer to use IDENT_CURRENT('tablename') or IDENT_SCOPE but these are not available on SQLCE
+		var r = connection.Query("select @@IDENTITY id", transaction: transaction, commandTimeout: commandTimeout);
+		return (int)r.First().id;
+	}
+}
+
+public class PostgresAdapter : ISqlAdapter
+{
+	public int Insert(IDbConnection connection, IDbTransaction transaction, int? commandTimeout, String tableName, string columnList, string parameterList, IEnumerable<PropertyInfo> keyProperties, object entityToInsert)
+	{
+		StringBuilder sb = new StringBuilder();
+		sb.AppendFormat("insert into {0} ({1}) values ({2})", tableName, columnList, parameterList);
+
+		sb.Append(" RETURNING ");
+		bool first = true;
+		foreach(var property in keyProperties)
+		{
+			if (!first)
+				sb.Append(", ");
+			first = false;
+			sb.Append(property.Name);
+		}
+		var results = connection.Query(sb.ToString(), entityToInsert, transaction: transaction, commandTimeout: commandTimeout);
+
+		// Return the key by assinging the corresponding property in the object - by product is that it supports compound primary keys
+		int id = 0;
+		foreach (var p in keyProperties)
+		{
+			var value = ((IDictionary<string, object>)results.First())[p.Name.ToLower()];
+			p.SetValue(entityToInsert, value, null);
+			if (id == 0)
+				id = Convert.ToInt32(value);
+		}
+		return id;
+	}
+}
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