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using System;
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using System.Collections;
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using System.Collections.Generic;
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using System.Linq;
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using System.Linq.Expressions;
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using System.Text;
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using System.Data;
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using System.Data.SqlTypes;
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using System.Data.Common;
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using Xunit;
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namespace LinqStudy.Test.LinqToObject
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{
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/// <summary>
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/// 转换运算符
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/// </summary>
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public class TypeConvertTest
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{
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/// <summary>
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/// AsEnumeralbe：
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/// System.Linq.Enumeralbe中，扩展方法
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/// AsEnumeralbe() 是延迟执行
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/// </summary>
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[Fact]
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public void AsEnumeralbe_Test()
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{
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DataTable dt=new DataTable();
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DataColumn col_id=new DataColumn("Id");
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col_id.AllowDBNull=false;
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col_id.AutoIncrementSeed=1;
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col_id.AutoIncrement=true;
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col_id.AutoIncrementStep=1;
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col_id.DataType=typeof(int);
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DataColumn col_name=new DataColumn("Name");
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col_name.AllowDBNull=true;
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col_name.AutoIncrement=false;
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col_name.DataType=typeof(string);
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col_name.DefaultValue=string.Empty;
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DataColumn col_age=new DataColumn("Age");
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col_age.AllowDBNull=false;
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col_age.AutoIncrement=false;
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col_age.DataType=typeof(int);
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col_age.DefaultValue=20;
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dt.Columns.Add(col_id);
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dt.Columns.Add(col_name);
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dt.Columns.Add(col_age);
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var row_one = dt.NewRow();
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row_one[1]="王高峰";
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row_one[2]=21;
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dt.Rows.Add(row_one);
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var cc = from row in dt.Select()
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select row;
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var dd = cc.ToList();
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}
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/// <summary>
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/// 1.IEnumeralbe 转换为 IQueryable
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/// 2.IEnumeralbe<T> 转换为 IQueryable<T>
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/// </summary>
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[Fact]
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public void AsQueryable_Test()
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{
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IEnumerable bb= Enumerable.Range(1,100);
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var cc=bb.AsQueryable();
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int[] t=new int[]{1,2,3};
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t.AsEnumerable();
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}
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}
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}
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