Add db.CodeFirst.GetDifferenceTables(types)

Src/Asp.Net/SqlServerTest/UnitTest/UCodeFirst.cs

@@ -72,9 +72,13 @@ namespace OrmTest
             Db.CodeFirst.InitTables<UnitCodeFirst131>();
             Db.Insertable(new UnitCodeFirst131() { Id = 1 }).ExecuteCommand();
             Db.CodeFirst.InitTables<UNITCODEFIRST131>();
+            var diffInfo = db.CodeFirst.GetDifferenceTables(typeof(UNITCOdEFIRST131)).ToDiffString();
+            db.CodeFirst.InitTables<UNITCOdEFIRST131>();
+            var diffInfo2 = db.CodeFirst.GetDifferenceTables(typeof(UNITCODEFIRST131)).ToDiffString();
             Db.CodeFirst.InitTables<UNITCOdEFIRST131>();
             Db.CodeFirst.InitTables<UnitTableUserName>();
             db.CodeFirst.InitTables<UnitTablename>();
+        
         }
         public class UnitCodeFirst131
         {

Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/CodeFirstProvider.cs

@@ -118,9 +118,61 @@ namespace SqlSugar
                 }
             }
         }
+        public TableDifferenceProvider GetDifferenceTables<T>()
+        {
+            var type = typeof(T);
+            return GetDifferenceTables(type);
+        }
+
+        public TableDifferenceProvider GetDifferenceTables(params Type[] types)
+        {
+            TableDifferenceProvider result = new TableDifferenceProvider();
+            foreach (var type in types)
+            {
+                GetDifferenceTables(result, type);
+            }
+            return result;
+        }
         #endregion
 
         #region Core Logic
+        private void GetDifferenceTables(TableDifferenceProvider result, Type type)
+        {
+            var tempTableName = "TempDiff" + DateTime.Now.ToString("yyMMssHHmmssfff");
+            var oldTableName = this.Context.EntityMaintenance.GetEntityInfo(type).DbTableName;
+            var db = new SqlSugarProvider(UtilMethods.CopyConfig(this.Context.CurrentConnectionConfig));
+            UtilMethods.IsNullReturnNew(db.CurrentConnectionConfig.ConfigureExternalServices);
+            db.CurrentConnectionConfig.ConfigureExternalServices.EntityNameService += (x, p) =>
+            {
+                p.IsDisabledUpdateAll = true;//Disabled update
+            };
+            db.MappingTables = new MappingTableList();
+            db.MappingTables.Add(type.Name, tempTableName);
+            try
+            {
+                db.CodeFirst.InitTables(type);
+                var tables = db.DbMaintenance.GetTableInfoList(false);
+                var oldTableInfo = tables.FirstOrDefault(it=>it.Name.EqualCase(oldTableName));
+                var newTableInfo = tables.FirstOrDefault(it => it.Name.EqualCase(oldTableName));
+                var oldTable = db.DbMaintenance.GetColumnInfosByTableName(oldTableName, false);
+                var tempTable = db.DbMaintenance.GetColumnInfosByTableName(tempTableName, false);
+                result.tableInfos.Add(new DiffTableInfo()
+                {
+                     OldTableInfo= oldTableInfo,
+                     NewTableInfo = newTableInfo,
+                     OldColumnInfos =  oldTable,
+                     NewColumnInfos = tempTable
+                });
+            }
+            catch (Exception ex)
+            {
+                throw ex;
+            }
+            finally
+            {
+                db.DbMaintenance.DropTable(tempTableName);
+            }
+        }
         protected virtual void Execute(Type entityType)
         {
             var entityInfo = this.Context.EntityMaintenance.GetEntityInfoNoCache(entityType);

Src/Asp.Net/SqlSugar/Abstract/CodeFirstProvider/TableDifferenceProvider.cs

@@ -0,0 +1,140 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Linq;
+namespace SqlSugar
+{
+    public class TableDifferenceProvider
+    {
+        internal List<DiffTableInfo> tableInfos = new List<DiffTableInfo>();
+        public string ToDiffString()
+        {
+            StringBuilder sb = new StringBuilder();
+            sb.AppendLine();
+            var diffTables = this.ToDiffList();
+            if (diffTables.IsNullOrEmpty())
+            {
+                sb.AppendLine("No change");
+            }
+            else
+            {
+                foreach (var item in diffTables)
+                {
+                    sb.AppendLine($"----Table:{ item.TableName }----");
+                    if (item.AddColums.HasValue())
+                    {
+                        sb.AppendLine($"Add column: ");
+                        foreach (var addItem in item.AddColums)
+                        {
+                            sb.AppendLine($"{addItem.Message} ");
+                        }
+                    }
+                    if (item.UpdateColums.HasValue())
+                    {
+                        sb.AppendLine($"Update column: ");
+                        foreach (var addItem in item.UpdateColums)
+                        {
+                            sb.AppendLine($"{addItem.Message} ");
+                        }
+                    }
+                    if (item.DeleteColums.HasValue())
+                    {
+                        sb.AppendLine($"Delete column: ");
+                        foreach (var addItem in item.DeleteColums) 
+                        {
+                            sb.AppendLine($"{addItem.Message} ");
+                        }
+                    }
+                }
+            }
+            sb.AppendLine();
+            sb.AppendLine();
+            return sb.ToString();
+        }
+
+        public List<TableDifferenceInfo> ToDiffList()
+        {
+            List<TableDifferenceInfo> result = new List<TableDifferenceInfo>();
+            foreach (var tableInfo in tableInfos)
+            {
+                TableDifferenceInfo addItem = new TableDifferenceInfo();
+                addItem.TableName = tableInfo.OldTableInfo.Name;
+                addItem.AddColums = GetAddColumn(tableInfo);
+                addItem.UpdateColums = GetUpdateColumn(tableInfo);
+                addItem.DeleteColums = GetDeleteColumn(tableInfo);
+                if (addItem.IsDiff)
+                    result.Add(addItem);
+            }
+            return result;
+        }
+
+        private static List<DiffColumsInfo> GetDeleteColumn(DiffTableInfo tableInfo)
+        {
+            List<DiffColumsInfo> result = new List<DiffColumsInfo>();
+            var columns = tableInfo.OldColumnInfos.Where(z => !tableInfo.NewColumnInfos.Any(y => y.DbColumnName.EqualCase(z.DbColumnName))).ToList();
+            return columns.Select(it => new DiffColumsInfo() {   Message= GetColumnString(it) }).ToList();
+        }
+
+        private List<DiffColumsInfo> GetUpdateColumn(DiffTableInfo tableInfo)
+        {
+            List<DiffColumsInfo> result = new List<DiffColumsInfo>();
+            result = tableInfo.NewColumnInfos
+                 .Where(z => tableInfo.OldColumnInfos.Any(y => y.DbColumnName.EqualCase(z.DbColumnName) && (
+                     z.Length != y.Length ||
+                     z.ColumnDescription != y.ColumnDescription ||
+                     z.DataType != y.DataType ||
+                     z.DecimalDigits != y.DecimalDigits
+                  ))).Select(it => new DiffColumsInfo()
+                  {
+                     Message=GetColumnString(it)
+                  }).ToList();
+            return result;
+        }
+
+        private static List<DiffColumsInfo> GetAddColumn(DiffTableInfo tableInfo)
+        {
+            List<DiffColumsInfo> result = new List<DiffColumsInfo>();
+            var columns = tableInfo.NewColumnInfos.Where(z => !tableInfo.OldColumnInfos.Any(y => y.DbColumnName.EqualCase(z.DbColumnName))).ToList();
+            return columns.Select(it => new DiffColumsInfo() {  Message = GetColumnString(it) }).ToList();
+        }
+
+        private static string GetColumnString(DbColumnInfo it)
+        {
+            return $"{it.DbColumnName}  {it.DataType}  {it.Length} {it.Scale}   default:{it.DefaultValue} description:{it.ColumnDescription} pk:{it.IsPrimarykey} nullable:{it.IsNullable} identity:{it.IsIdentity} ";
+        }
+    }
+    public class TableDifferenceInfo
+    {
+        public List<DiffColumsInfo> DeleteColums { get; set; } = new List<DiffColumsInfo>();
+        public List<DiffColumsInfo> UpdateColums { get; set; } = new List<DiffColumsInfo>();
+        public List<DiffColumsInfo> AddColums { get; set; } = new List<DiffColumsInfo>();
+        public List<DiffColumsInfo> UpdateRemark { get; set; } = new List<DiffColumsInfo>();
+        public bool IsDiff
+        {
+            get
+            {
+                return
+                    (DeleteColums.Count>0 ||
+                     UpdateColums.Count > 0 ||
+                     AddColums.Count > 0 ||
+                     UpdateRemark.Count > 0) ;
+            }
+        }
+
+        public string TableName { get;  set; }
+    }
+
+    public class DiffColumsInfo
+    {
+        public string SqlTemplate { get; set; }
+        public string Message { get; set; }
+    }
+
+    public class DiffTableInfo
+    {
+        public DbTableInfo OldTableInfo { get; set; }
+        public DbTableInfo NewTableInfo { get; set; }
+        public List<DbColumnInfo> OldColumnInfos { get; set; }
+        public List<DbColumnInfo> NewColumnInfos { get; set; }
+    }
+}

Src/Asp.Net/SqlSugar/Interface/ICodeFirst.cs

@@ -18,5 +18,7 @@ namespace SqlSugar
         void InitTables<T, T2, T3>();
         void InitTables<T, T2, T3, T4>();
         SplitCodeFirstProvider SplitTables();
+        TableDifferenceProvider GetDifferenceTables<T>();
+        TableDifferenceProvider GetDifferenceTables(params Type[] types);
     }
 }

Src/Asp.Net/SqlSugar/SqlSugar.csproj

@@ -71,6 +71,7 @@
   <ItemGroup>
     <Compile Include="Abstract\AopProvider\AopProvider.cs" />
     <Compile Include="Abstract\CacheProvider\CacheProvider.cs" />
+    <Compile Include="Abstract\CodeFirstProvider\TableDifferenceProvider.cs" />
     <Compile Include="Abstract\CodeFirstProvider\CodeFirstProvider.cs" />
     <Compile Include="Abstract\AdoProvider\AdoAccessory.cs" />
     <Compile Include="Abstract\CodeFirstProvider\SplitCodeFirstProvider.cs" />