Merge pull request #729 from KaneLeung/master

🚀增加分页模型分页及示例

FreeSql/Internal/CommonProvider/SelectProvider/Select0Provider.cs

@@ -319,6 +319,13 @@ namespace FreeSql.Internal.CommonProvider
             return this.Limit(pageSize) as TSelect;
         }
 
+        public TSelect Page(BasePagingInfo pagingInfo)
+        {
+            pagingInfo.Count = this.Count();
+            this.Skip(Math.Max(0, pagingInfo.PageNumber - 1) * pagingInfo.PageSize);
+            return this.Limit(pagingInfo.PageSize) as TSelect;
+        }
+
         public TSelect Skip(int offset)
         {
             _skip = offset;

FreeSql/Internal/CommonProvider/SelectProvider/SelectGroupingProvider.cs

@@ -201,6 +201,14 @@ namespace FreeSql.Internal.CommonProvider
             return this;
         }
 
+        public ISelectGrouping<TKey, TValue> Page(BasePagingInfo pagingInfo)
+        {
+            pagingInfo.Count = this.Count();
+            _groupBySkip = Math.Max(0, pagingInfo.PageNumber - 1) * pagingInfo.PageSize;
+            _groupByLimit = pagingInfo.PageSize;
+            return this;
+        }
+
         public long Count() => _select._cancel?.Invoke() == true ? 0 : long.TryParse(string.Concat(_orm.Ado.ExecuteScalar(_select._connection, _select._transaction, CommandType.Text, $"select count(1) from ({this.ToSql($"1{_comonExp._common.FieldAsAlias("as1")}")}) fta", _select._commandTimeout, _select._params.ToArray())), out var trylng) ? trylng : default(long);
         public ISelectGrouping<TKey, TValue> Count(out long count)
         {

FreeSql/Internal/Model/BasePagingInfo.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace FreeSql.Internal.Model
+{
+    /// <summary>
+    /// 分页信息
+    /// </summary>
+    public class BasePagingInfo
+    {
+        /// <summary>
+        /// 第几页，从1开始
+        /// </summary>
+        public int PageNumber { get; set; }
+        /// <summary>
+        /// 每页多少
+        /// </summary>
+        public int PageSize { get; set; }
+        /// <summary>
+        /// 查询的记录数量
+        /// </summary>
+        public long Count { get; set; }
+    }
+}