SQL 、LINQ日前比较
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Text;
using System.Threading.Tasks; namespace ConsoleApp3
{
class Program
{
static void Main(string[] args)
{
var queryJson = "";
var queryParam = queryJson.ToJObject();
DateTime startTime = queryParam["StartTime"].ToDate();
DateTime endTime = queryParam["EndTime"].ToDate();
//DateTime endTime = queryParam["EndTime"].ToDate().AddDays(1);//结束时间
//Ling比较
List<test> query = new List<test>();
var list = query.Where(t => t.F_LogTime>= startTime && t.F_LogTime < endTime);
//SQL比较
var sql = "SELECT" + DbTimeType.DbTimeTypeFormat("F_LogTime", DbHelper.DbType) +" FROM DUAL WHERE F_LogTime>=" + DbTimeType.DateTimeToDbTimeType(startTime, DbHelper.DbType) + "AND F_LogTime<=" + DbTimeType.DateTimeToDbTimeType(endTime, DbHelper.DbType);
sql += " and F_LogTime>=" + DbTimeType.DateTimeToDbTimeType(startTime, DbHelper.DbType) + " and F_LogTime<" + DbTimeType.DateTimeToDbTimeType(endTime, DbHelper.DbType);
} }
public class test
{
public DateTime? F_LogTime { get; set; }
}
}
一、建立一个数据库帮助类 DbHelper
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace ConsoleApp3
{
public class DbHelper
{
/// <summary>
/// 数据库类型
/// </summary>
public static DatabaseType DbType { get; set; } #region 构造函数
/// <summary>
/// 构造方法
/// </summary>
public DbHelper(DbConnection _dbConnection)
{
dbConnection = _dbConnection;
dbCommand = dbConnection.CreateCommand();
dbCommand.CommandTimeout = CommandTimeout = ;
}
#endregion #region 属性
/// <summary>
/// 执行超时时间
/// </summary>
public int CommandTimeout
{
get
{
return dbCommand.CommandTimeout;
}
set
{
dbCommand.CommandTimeout = value;
}
} /// <summary>
/// 数据库连接对象
/// </summary>
private DbConnection dbConnection { get; set; }
/// <summary>
/// 执行命令对象
/// </summary>
private IDbCommand dbCommand { get; set; }
/// <summary>
/// 关闭数据库连接
/// </summary>
public void Close()
{
if (dbConnection != null)
{
dbConnection.Close();
dbConnection.Dispose();
}
if (dbCommand != null)
{
dbCommand.Dispose();
}
}
#endregion /// <summary>
/// 执行SQL返回 DataReader
/// </summary>
/// <param name="cmdType">命令的类型</param>
/// <param name="strSql">Sql语句</param>
/// <returns></returns>
public IDataReader ExecuteReader(CommandType cmdType, string strSql)
{
//Oracle.DataAccess.Client
return ExecuteReader(cmdType, strSql, null);
}
/// <summary>
/// 执行SQL返回 DataReader
/// </summary>
/// <param name="cmdType">命令的类型</param>
/// <param name="strSql">Sql语句</param>
/// <param name="dbParameter">Sql参数</param>
/// <returns></returns>
public IDataReader ExecuteReader(CommandType cmdType, string strSql, params DbParameter[] dbParameter)
{
try
{
PrepareCommand(dbConnection, dbCommand, null, cmdType, strSql, dbParameter);
IDataReader rdr = dbCommand.ExecuteReader(CommandBehavior.CloseConnection);
return rdr;
}
catch (Exception)
{
Close();
throw;
}
}
/// <summary>
/// 执行查询，并返回查询所返回的结果集
/// </summary>
/// <param name="cmdType">命令的类型</param>
/// <param name="strSql">Sql语句</param>
/// <returns></returns>
public object ExecuteScalar(CommandType cmdType, string strSql)
{
return ExecuteScalar(cmdType, strSql);
}
/// <summary>
/// 执行查询，并返回查询所返回的结果集
/// </summary>
/// <param name="cmdType">命令的类型</param>
/// <param name="strSql">Sql语句</param>
/// <param name="dbParameter">Sql参数</param>
/// <returns></returns>
public object ExecuteScalar(CommandType cmdType, string cmdText, params DbParameter[] parameters)
{
try
{
PrepareCommand(dbConnection, dbCommand, null, cmdType, cmdText, parameters);
object val = dbCommand.ExecuteScalar();
dbCommand.Parameters.Clear();
return val;
}
catch (Exception)
{
Close();
throw;
}
}
/// <summary>
/// 为即将执行准备一个命令
/// </summary>
/// <param name="conn">SqlConnection对象</param>
/// <param name="cmd">SqlCommand对象</param>
/// <param name="isOpenTrans">DbTransaction对象</param>
/// <param name="cmdType">执行命令的类型（存储过程或T-SQL，等等）</param>
/// <param name="cmdText">存储过程名称或者T-SQL命令行, e.g. Select * from Products</param>
/// <param name="dbParameter">执行命令所需的sql语句对应参数</param>
private void PrepareCommand(DbConnection conn, IDbCommand cmd, DbTransaction isOpenTrans, CommandType cmdType, string cmdText, params DbParameter[] dbParameter)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;//DbParameters.ToDbSql(cmdText);
if (isOpenTrans != null)
cmd.Transaction = isOpenTrans;
cmd.CommandType = cmdType;
if (dbParameter != null)
{
dbParameter = DbParameters.ToDbParameter(dbParameter);
foreach (var parameter in dbParameter)
{
cmd.Parameters.Add(parameter);
}
}
}
}
}
二、建立一个数据库类型类 DatabaseType
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace ConsoleApp3
{
public enum DatabaseType
{
/// <summary>
/// 数据库类型：SqlServer
/// </summary>
SqlServer,
/// <summary>
/// 数据库类型：MySql
/// </summary>
MySql,
/// <summary>
/// 数据库类型：Oracle
/// </summary>
Oracle,
/// <summary>
/// 数据库类型：Access
/// </summary>
Access,
/// <summary>
/// 数据库类型：SQLite
/// </summary>
SQLite
}
}
三、日期处理类 DbTimeType
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace ConsoleApp3
{
public class DbTimeType
{
public static string DateTimeToDbTimeType(DateTime time, DatabaseType dbType = DatabaseType.Oracle)
{
string result = string.Empty;
switch (dbType)
{
case DatabaseType.SqlServer:
result = "'" + time.ToString("yyyy-MM-dd HH:mm:ss") + "'";
break;
case DatabaseType.MySql:
result = "'" + time.ToString("yyyy-MM-dd HH:mm:ss") + "'";
break;
case DatabaseType.Oracle:
result = "TO_DATE('" + time.ToString("yyyy-MM-dd HH:mm:ss") + "', 'yyyy-MM-dd HH24:MI:ss')";
break;
default:
throw new Exception("数据库类型目前不支持！");
}
return result;
}
public static string DbTimeTypeFormat(string colunmName, DatabaseType dbType = DatabaseType.SqlServer)
{
string result = string.Empty;
switch (dbType)
{
case DatabaseType.SqlServer:
{
result = "CONVERT(varchar(100)," + colunmName + ", 102)";
break;
}
case DatabaseType.MySql:
{
result = "DATE_FORMAT(" + colunmName + ",'%Y-%m-%d')";
break;
}
case DatabaseType.Oracle:
{
result = "to_char(" + colunmName + ",'yyyy-MM-dd')";
break;
}
default:
{
throw new Exception("数据库类型目前不支持！");
}
}
return result;
} }
}
四、Json操作类 Json
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace ConsoleApp3
{
/// <summary>
/// Json操作
/// </summary>
public static class Json
{
public static object ToJson(this string Json)
{
return Json == null ? null : JsonConvert.DeserializeObject(Json);
}
public static string ToJson(this object obj)
{
var timeConverter = new IsoDateTimeConverter { DateTimeFormat = "yyyy-MM-dd HH:mm:ss" };
return JsonConvert.SerializeObject(obj, timeConverter);
}
public static string ToJson(this object obj, string datetimeformats)
{
var timeConverter = new IsoDateTimeConverter { DateTimeFormat = datetimeformats };
return JsonConvert.SerializeObject(obj, timeConverter);
}
public static T ToObject<T>(this string Json)
{
return Json == null ? default(T) : JsonConvert.DeserializeObject<T>(Json);
}
public static List<T> ToList<T>(this string Json)
{
return Json == null ? null : JsonConvert.DeserializeObject<List<T>>(Json);
}
public static DataTable ToTable(this string Json)
{
return Json == null ? null : JsonConvert.DeserializeObject<DataTable>(Json);
}
public static JObject ToJObject(this string Json)
{
return Json == null ? JObject.Parse("{}") : JObject.Parse(Json.Replace(" ", ""));
}
}
}
五、类型转换扩展类 Extensions
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace ConsoleApp3
{
/// <summary>
/// 类型转换扩展
/// </summary>
public static partial class Extensions
{
#region 数值转换
/// <summary>
/// 转换为整型
/// </summary>
/// <param name="data">数据</param>
public static int ToInt(this object data)
{
if (data == null)
return ;
int result;
var success = int.TryParse(data.ToString(), out result);
if (success)
return result;
try
{
return Convert.ToInt32(ToDouble(data, ));
}
catch (Exception)
{
return ;
}
} /// <summary>
/// 转换为可空整型
/// </summary>
/// <param name="data">数据</param>
public static int? ToIntOrNull(this object data)
{
if (data == null)
return null;
int result;
bool isValid = int.TryParse(data.ToString(), out result);
if (isValid)
return result;
return null;
} /// <summary>
/// 转换为双精度浮点数
/// </summary>
/// <param name="data">数据</param>
public static double ToDouble(this object data)
{
if (data == null)
return ;
double result;
return double.TryParse(data.ToString(), out result) ? result : ;
} /// <summary>
/// 转换为双精度浮点数,并按指定的小数位4舍5入
/// </summary>
/// <param name="data">数据</param>
/// <param name="digits">小数位数</param>
public static double ToDouble(this object data, int digits)
{
return Math.Round(ToDouble(data), digits);
} /// <summary>
/// 转换为可空双精度浮点数
/// </summary>
/// <param name="data">数据</param>
public static double? ToDoubleOrNull(this object data)
{
if (data == null)
return null;
double result;
bool isValid = double.TryParse(data.ToString(), out result);
if (isValid)
return result;
return null;
} /// <summary>
/// 转换为高精度浮点数
/// </summary>
/// <param name="data">数据</param>
public static decimal ToDecimal(this object data)
{
if (data == null)
return ;
decimal result;
return decimal.TryParse(data.ToString(), out result) ? result : ;
} /// <summary>
/// 转换为高精度浮点数,并按指定的小数位4舍5入
/// </summary>
/// <param name="data">数据</param>
/// <param name="digits">小数位数</param>
public static decimal ToDecimal(this object data, int digits)
{
return Math.Round(ToDecimal(data), digits);
} /// <summary>
/// 转换为可空高精度浮点数
/// </summary>
/// <param name="data">数据</param>
public static decimal? ToDecimalOrNull(this object data)
{
if (data == null)
return null;
decimal result;
bool isValid = decimal.TryParse(data.ToString(), out result);
if (isValid)
return result;
return null;
} /// <summary>
/// 转换为可空高精度浮点数,并按指定的小数位4舍5入
/// </summary>
/// <param name="data">数据</param>
/// <param name="digits">小数位数</param>
public static decimal? ToDecimalOrNull(this object data, int digits)
{
var result = ToDecimalOrNull(data);
if (result == null)
return null;
return Math.Round(result.Value, digits);
} #endregion #region 日期转换
/// <summary>
/// 转换为日期
/// </summary>
/// <param name="data">数据</param>
public static DateTime ToDate(this object data)
{
if (data == null)
return DateTime.MinValue;
DateTime result;
return DateTime.TryParse(data.ToString(), out result) ? result : DateTime.MinValue;
} /// <summary>
/// 转换为可空日期
/// </summary>
/// <param name="data">数据</param>
public static DateTime? ToDateOrNull(this object data)
{
if (data == null)
return null;
DateTime result;
bool isValid = DateTime.TryParse(data.ToString(), out result);
if (isValid)
return result;
return null;
} #endregion #region 布尔转换
/// <summary>
/// 转换为布尔值
/// </summary>
/// <param name="data">数据</param>
public static bool ToBool(this object data)
{
if (data == null)
return false;
bool? value = GetBool(data);
if (value != null)
return value.Value;
bool result;
return bool.TryParse(data.ToString(), out result) && result;
} /// <summary>
/// 获取布尔值
/// </summary>
private static bool? GetBool(this object data)
{
switch (data.ToString().Trim().ToLower())
{
case "":
return false;
case "":
return true;
case "是":
return true;
case "否":
return false;
case "yes":
return true;
case "no":
return false;
default:
return null;
}
} /// <summary>
/// 转换为可空布尔值
/// </summary>
/// <param name="data">数据</param>
public static bool? ToBoolOrNull(this object data)
{
if (data == null)
return null;
bool? value = GetBool(data);
if (value != null)
return value.Value;
bool result;
bool isValid = bool.TryParse(data.ToString(), out result);
if (isValid)
return result;
return null;
} #endregion #region 字符串转换
/// <summary>
/// 转换为字符串
/// </summary>
/// <param name="data">数据</param>
public static string ToString(this object data)
{
return data == null ? string.Empty : data.ToString().Trim();
}
#endregion
}
}
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