From 1356ee0e515c8b2eb6a343e8d1e4684343ecb53f Mon Sep 17 00:00:00 2001
From: "Valeriano A.R" <valen.alfonso@gmail.com>
Date: Fri, 2 Aug 2019 08:48:59 +0200
Subject: [PATCH] ExportData: Split command batches of 1MiB.

---
 .../Code/BusinessLogic/TableBL.cs             |  3 +++
 VAR.DatabaseExplorer/Code/DataTableHelper.cs  | 20 ++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/VAR.DatabaseExplorer/Code/BusinessLogic/TableBL.cs b/VAR.DatabaseExplorer/Code/BusinessLogic/TableBL.cs
index 38fc176..1f3c5c4 100644
--- a/VAR.DatabaseExplorer/Code/BusinessLogic/TableBL.cs
+++ b/VAR.DatabaseExplorer/Code/BusinessLogic/TableBL.cs
@@ -31,7 +31,9 @@ namespace VAR.DatabaseExplorer.Code.BusinessLogic
             txtWriter.WriteLine(string.Format("DELETE FROM {0};", tableFullName));
             txtWriter.WriteLine(string.Format("DBCC CHECKIDENT ('{0}', RESEED, 0);", tableFullName));
             txtWriter.WriteLine(string.Format("SET IDENTITY_INSERT {0} ON;", tableFullName));
+            txtWriter.WriteLine("GO");
             DataTableHelper.DataTable_GenerateInserts(txtWriter, dtData, tableFullName);
+            txtWriter.WriteLine("GO");
             txtWriter.WriteLine(string.Format("SET IDENTITY_INSERT {0} OFF;", tableFullName));
             txtWriter.WriteLine("GO");
             txtWriter.WriteLine(string.Empty);
@@ -43,6 +45,7 @@ namespace VAR.DatabaseExplorer.Code.BusinessLogic
 
             txtWriter.WriteLine(string.Format("-- {0}", tableFullName));
             txtWriter.WriteLine(string.Format("DELETE FROM {0};", tableFullName));
+            txtWriter.WriteLine("GO");
             DataTableHelper.DataTable_GenerateInserts(txtWriter, dtData, tableFullName);
             txtWriter.WriteLine("GO");
             txtWriter.WriteLine(string.Empty);
diff --git a/VAR.DatabaseExplorer/Code/DataTableHelper.cs b/VAR.DatabaseExplorer/Code/DataTableHelper.cs
index a2d34f2..595f7af 100644
--- a/VAR.DatabaseExplorer/Code/DataTableHelper.cs
+++ b/VAR.DatabaseExplorer/Code/DataTableHelper.cs
@@ -10,6 +10,8 @@ namespace VAR.DatabaseExplorer.Code
     {
         public static void DataTable_GenerateInserts(TextWriter txtWriter, DataTable dataTable, string destTable)
         {
+            const int OneMegaByte = 1 * 1024 * 1024;
+            const int MaxSizePerBatch = OneMegaByte;
             var nfi = new NumberFormatInfo { NumberDecimalSeparator = "." };
 
             var sbColumns = new StringBuilder();
@@ -19,7 +21,7 @@ namespace VAR.DatabaseExplorer.Code
                 if (sbColumns.Length > 0) { sbColumns.Append(", "); }
                 sbColumns.AppendFormat("[{0}]", dc.ColumnName);
             }
-
+            int size = 0;
             // Recorrer la tabla de datos
             foreach (DataRow dr in dataTable.Rows)
             {
@@ -69,12 +71,12 @@ namespace VAR.DatabaseExplorer.Code
                         }
                         else if (type == "byte[]")
                         {
-                            // Arrays de bytes (imagenes, archivos etc)
+                            // Arrays de bytes (imágenes, archivos etc)
                             sbValues.AppendFormat("0x{0}", BitConverter.ToString(((byte[])valor)).Replace("-", ""));
                         }
                         else if (type == "datetime")
                         {
-                            // DateTIme
+                            // DateTime
                             sbValues.AppendFormat("'{0}'", ((DateTime)valor).ToString("yyyy-MM-dd HH:mm:ss"));
                         }
                         else
@@ -86,8 +88,16 @@ namespace VAR.DatabaseExplorer.Code
                 }
 
                 // Insertar fila a la datatable destino
-                txtWriter.WriteLine(string.Format("INSERT INTO {0} ({1}) VALUES ({2});",
-                    destTable, sbColumns.ToString(), sbValues.ToString()));
+                string strLine = string.Format("INSERT INTO {0} ({1}) VALUES ({2});",
+                    destTable, sbColumns.ToString(), sbValues.ToString());
+                if ((size + strLine.Length) >= MaxSizePerBatch)
+                {
+                    txtWriter.WriteLine("PRINT '...';");
+                    txtWriter.WriteLine("GO");
+                    size = 0;
+                }
+                size += strLine.Length;
+                txtWriter.WriteLine(strLine);
             }
         }
     }