- 增加 IUpdate<T> BulkCopy 批量更新扩展方法（暂时支持 SqlServer/MySql/PostgreSQL）；

Providers/FreeSql.Provider.SqlServer/SqlServerExtensions.cs

@@ -5,6 +5,10 @@ using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Threading;
 using FreeSql.Internal.CommonProvider;
+using System.Linq;
+using System.Text;
+using System.Data.Common;
+using FreeSql.Internal.ObjectPool;
 #if microsoft
 using Microsoft.Data.SqlClient;
 #else
@@ -115,6 +119,65 @@ public static partial class FreeSqlSqlServerGlobalExtensions
     internal static ConcurrentDictionary<Guid, NativeTuple<SqlServerLock, Dictionary<Type, bool>>> _dicSetGlobalSelectWithLock = new ConcurrentDictionary<Guid, NativeTuple<SqlServerLock, Dictionary<Type, bool>>>();
 
     #region ExecuteSqlBulkCopy
+    /// <summary>
+    /// 批量更新（更新字段数量超过 2000 时收益大）<para></para>
+    /// 实现原理：使用 SqlBulkCopy 插入临时表，再使用 UPDATE INNER JOIN 联表更新
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    /// <param name="that"></param>
+    /// <param name="copyOptions"></param>
+    /// <param name="batchSize"></param>
+    /// <param name="bulkCopyTimeout"></param>
+    /// <returns></returns>
+    public static int ExecuteSqlBulkCopy<T>(this IUpdate<T> that, SqlBulkCopyOptions copyOptions = SqlBulkCopyOptions.Default, int? batchSize = null, int? bulkCopyTimeout = null) where T : class
+    {
+        var update = that as UpdateProvider<T>;
+        if (update._source.Any() != true || update._tempPrimarys.Any() == false) return 0;
+        var state = ExecuteSqlBulkCopyState(update);
+        return UpdateProvider.ExecuteBulkUpdate(update, state, insert => insert.ExecuteSqlBulkCopy(copyOptions, batchSize, bulkCopyTimeout));
+    }
+    static NativeTuple<string, string, string, string> ExecuteSqlBulkCopyState<T>(UpdateProvider<T> update) where T : class
+    {
+        if (update._source.Any() != true) return null;
+        var _table = update._table;
+        var _tempPrimarys = update._tempPrimarys;
+        var _commonUtils = update._commonUtils;
+        var _ignore = update._ignore;
+        var updateTableName = update._tableRule?.Invoke(_table.DbName) ?? _table.DbName;
+        var tempTableName = $"#Temp_{updateTableName}";
+        if (update._connection == null)
+        {
+            if (update._orm.Ado.TransactionCurrentThread != null)
+                update.WithTransaction(update._orm.Ado.TransactionCurrentThread);
+        }
+        var sql1 = $"SELECT * INTO {tempTableName} FROM {_commonUtils.QuoteSqlName(updateTableName)} WHERE 1=2";
+        var sb = new StringBuilder().Append("UPDATE ").Append(" a SET \r\n ");
+        var colidx = 0;
+        foreach (var col in _table.Columns.Values)
+        {
+            if (col.Attribute.IsPrimary) continue;
+            if (_tempPrimarys.Any(a => a.CsName == col.CsName)) continue;
+            if (col.Attribute.IsIdentity == false && col.Attribute.IsVersion == false && _ignore.ContainsKey(col.Attribute.Name) == false)
+            {
+                if (colidx > 0) sb.Append(", \r\n ");
+                sb.Append("  a.").Append(_commonUtils.QuoteSqlName(col.Attribute.Name)).Append(" = ").Append("b.").Append(_commonUtils.QuoteSqlName(col.Attribute.Name));
+                ++colidx;
+            }
+        }
+        sb.Append(" \r\nFROM ").Append(_commonUtils.QuoteSqlName(updateTableName)).Append(" a ")
+            .Append(" \r\nINNER JOIN ").Append(tempTableName).Append(" b ON ");
+        for (var a = 0; a < _tempPrimarys.Length; a++)
+        {
+            var pkname = _commonUtils.QuoteSqlName(_tempPrimarys[a].Attribute.Name);
+            if (a > 0) sb.Append(" AND ");
+            sb.Append("b.").Append(pkname).Append(" = a.").Append(pkname);
+        }
+        var sql2 = sb.ToString();
+        sb.Clear();
+        var sql3 = $"DROP TABLE {tempTableName}";
+        return NativeTuple.Create(sql1, sql2, sql3, tempTableName);
+    }
+
     /// <summary>
     /// SqlServer SqlCopyBulk 批量插入功能<para></para>
     /// 使用 IgnoreColumns/InsertColumns 设置忽略/指定导入的列<para></para>
@@ -214,6 +277,13 @@ public static partial class FreeSqlSqlServerGlobalExtensions
     }
 #if net40
 #else
+    public static Task<int> ExecuteSqlBulkCopyAsync<T>(this IUpdate<T> that, SqlBulkCopyOptions copyOptions = SqlBulkCopyOptions.Default, int? batchSize = null, int? bulkCopyTimeout = null, CancellationToken cancellationToken = default) where T : class
+    {
+        var update = that as UpdateProvider<T>;
+        if (update._source.Any() != true || update._tempPrimarys.Any() == false) return Task.FromResult(0);
+        var state = ExecuteSqlBulkCopyState(update);
+        return UpdateProvider.ExecuteBulkUpdateAsync(update, state, insert => insert.ExecuteSqlBulkCopyAsync(copyOptions, batchSize, bulkCopyTimeout, cancellationToken));
+    }
     async public static Task ExecuteSqlBulkCopyAsync<T>(this IInsert<T> that, SqlBulkCopyOptions copyOptions = SqlBulkCopyOptions.Default, int? batchSize = null, int? bulkCopyTimeout = null, CancellationToken cancellationToken = default) where T : class
     {
         var insert = that as FreeSql.SqlServer.Curd.SqlServerInsert<T>;