C# 连接数据库 以及数据库增删改查

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MySql.Data;
using MySql.Data.MySqlClient;
using System.Data;

class DataBaceTool
{

public MySqlConnection conn;
//打开数据库
public void OpenDataBace()
{
string host = "localhost";
string id = "root";
string pwd = "hololens";
string database = "airport";
string result = "";
string connectionString = string.Format("Server = {0}; Database = {1}; User ID = {2}; Password = {3};", host, database, id, pwd);
conn = new MySqlConnection(connectionString);
try
{
conn.Open();
result = conn.ServerVersion;
Console.Write("打开成功 MySql版本" + result);
}
catch (Exception ex)
{
Console.Write(ex.ToString() + "打开报错");
}
}
// 关闭数据库
public void CloseDataBace()
{
try
{
conn.Close();
conn = null;
Console.Write("关闭成功");
}
catch (Exception ex)
{
Console.Write(ex.ToString() + "关闭报错");
}
}

//删除表，传入表的名称
public void ClearDataFromTable(string tableName)
{
try
{
string sql = " delete from " + tableName + ";";
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();
rdr.Close();
}
catch (MySqlException exc)
{
Console.Write("删除失败" + exc);
}
}

//根据key更新表中 一行里多个列的值 我的flightNum是关键key
public void UpdateMultiDataFromTable(string tableName,string flightNum,Dictionary<string, object> updateDic)
{
try
{
string sql = "update " + tableName + " set ";
foreach(string key in updateDic.Keys)
{
sql += (key + "='" + updateDic[key] + "',");
}
sql  =  sql.Remove(sql.LastIndexOf(','),  1);
sql +=( "where " + "flightNum" + " ='" + flightNum + "';");
MySqlCommand cmd = new MySqlCommand(sql, conn);
cmd.ExecuteNonQuery();
Console.Write("修改成功");
}
catch (MySqlException exc)
{
Console.Write("修改失败" + exc);
}
}
//根据表明更新某一列的指 我的flightNum是关键key
public void UpdateDataFormTable(string tableName, string keyword, string key, string value)
{
try
{
string  sql = "update " + tableName + " set " + key + "='" + value + "' " + "where " + "flightNum" + " ='" + keyword + "';";

MySqlCommand cmd = new MySqlCommand(sql, conn);
cmd.ExecuteNonQuery();
Console.Write("修改成功");
}
catch (MySqlException)
{
Console.Write("修改失败");
}
}

//机场表插入输入
public void InsertAirportData(string TableName, List<Dictionary<string, object>> list)
{
//先清除一次 机场表
ClearDataFromTable("AirportManager");
for (int i = 0; i < list.Count; i++)
{
try
{
string sql = "insert into " + TableName + " (airportName,airportPos,id,tag,weather)values('" + list[i]["airportName"] + "','" + list[i]["airportPos"] + "','" + (i + 1) +"','"+list[i]["tag"] + "','" + list[i]["weather"]  + "');";
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();
rdr.Close();
Console.Write("机场信息储存成功");
}
catch (MySqlException exc)
{
Console.Write("机场信息存储错误" + exc);
}
}
}

//删除一行
public  void DeleteLine(string tableName, string key, string value)
{
try
{
string sql = "delete from " + tableName + " where " + key + " = '" + value + "';";
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();
rdr.Close();
Console.Write("删除成功");
}
catch(MySqlException exc)
{
Console.WriteLine("删除失败" + exc);
}
}

//插入数据
public void InsertFlighInfoData(string TableName, List<Dictionary<string, object>> list)
{
for (int i = 0; i < list.Count; i++)
{
try
{
string sql = "insert into " + TableName + " (flightNum,departurePlace,departureTime,startStation,endStation,arrivalTime,destinationPlace,state,speed,flightHeight,flightState,comName,delayDT,actualAT,oilInfo,timeProportion)values('" + list[i]["flightNum"] + "','" + list[i]["departurePlace"] + "','" + list[i]["departureTime"] + "','" + list[i]["startStation"] + "','" + list[i]["endStation"] + "','" + list[i]["arrivalTime"] + "','" + list[i]["destinationPlace"] + "','" + list[i]["state"] + "','" + list[i]["speed"] + "','" + list[i]["flightHeight"] + "','" + list[i]["flightState"] + "','" + list[i]["comName"] + "','" + list[i]["delayDT"] + "','" + list[i]["actualAT"] + "','" + list[i]["oilInfo"] + "','" + list[i]["timeProportion"] + "');";
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();
rdr.Close();
Console.Write("航班列表存入成功");
}
catch (MySqlException exc)
{
Console.Write("航班列表存入失败" + exc);
}
}
}

// 查询为完成的航班信息 查询特定条件（这里查询state = 2的值）
public  List<Dictionary<string,object>> QueryDataFromCondition(string tableName)
{
//新改的返回列的数据
string sql = "select * from  " + tableName + " where state <> 2";
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();

List<Dictionary<string, object>> list = new List<Dictionary<string, object>>();
while (rdr.Read())
{
Dictionary<string, object> dic = new Dictionary<string, object>();
if (tableName == "RouteManager")
{
//这个方法时把值添加到字典里
AddFlightmanagementTableData(dic, rdr);
}

list.Add(dic);
}
rdr.Close();

return list;
}

//查询表中所有数据
public List<Dictionary<string, object>> QueryAllDataFromTable(string tableName)
{
//新改的返回列的数据
string sql = "select * from  " + tableName;
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();

List<Dictionary<string, object>> list = new List<Dictionary<string, object>>();
while (rdr.Read())
{
Dictionary<string, object> dic = new Dictionary<string, object>();
if (tableName == "RouteManager")
{
AddFlightmanagementTableData(dic, rdr);
}
list.Add(dic);
}
rdr.Close();
return list;
}

//获取表中指定行数据
public List<Dictionary<string, object>> QuerySpacificDataFromTable(string tableName, string key, string value)
{
List<Dictionary<string, object>> list = new List<Dictionary<string, object>>();
string sql = "select * from  " + tableName + " where " + key + "='" + value + "'; ";
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();
while (rdr.Read())
{
Dictionary<string, object> dic = new Dictionary<string, object>();
if (tableName == "RouteManager")
{
AddFlightData(dic, rdr);
}
list.Add(dic);
}
Console.Write("list数量" + list.Count);
rdr.Close();
return list;
}

public void AddFlightData(Dictionary<string, object> dic, MySqlDataReader rdr)
{
dic.Add("flightNum", rdr.GetString(rdr.GetOrdinal("flightNum")));
dic.Add("departurePlace", rdr.GetString(rdr.GetOrdinal("departurePlace")));
dic.Add("ID", rdr.GetInt64(rdr.GetOrdinal("ID")));
}

//获取单张表中行的数据
public Dictionary<string, object> QuerySingleDataFromTable(string tableName, string id)
{
string sql = "select * from  " + tableName + " where id=" + id + "; ";
MySqlCommand cmd = new MySqlCommand(sql, conn);
MySqlDataReader rdr = cmd.ExecuteReader();
Dictionary<string, object> dic = new Dictionary<string, object>();
while (rdr.Read())
{
if (tableName == "RouteManager")
{
AddFlightmanagementTableData(dic, rdr);
}
}
rdr.Close();
return dic;
}