我们在开发 WPF 桌面应用程序时，数据库存的使用是必不可少的，除非你的应用没有数据存储的需求，有了数据存储需求，我们就会面临使用什么样的数据库的选择问题，我的选择方案是，单机版的应用我优先选择 Sqlite，如果钓多台电脑需要数据共享我优先MySql 8.0+，Sqlite 和MySql 都支持标准的SQL 结构查询语句，数据库的切换也不需要额外大量的开发工作。单机版使用Sqlite ，免去 MySql 安装过程，减少用户的操作，降低使用门槛。
之前的很多应用都是使用 MySql 。现在记录下对 Sqlite 数据的基本使用。
准备两张表和C# 实体类，代码如下
public class BaseEntity
{
public Int64 id;
public Int64 Id
{
get
{
return id;
}
set
{
id = value;
}
}
} //车辆作息
public class Car : BaseEntity
{
public string carNumber;
public decimal traeWeight;
public string driver;
public string driverMobile;
} //货物信息 Material
public class Marteral :BaseEntity
{
public string name;
public string firstCase;
}
对应的表结构
CREATE TABLE "main"."marteral" (
"id" INTEGER NOT NULL,
"name" TEXT(255) DEFAULT NULL,
"first_case" TEXT(255) DEFAULT NULL,
PRIMARY KEY ("id" ASC)
);
CREATE TABLE "main"."car" (
"id" bigint NOT NULL,
"car_number" TEXT(255) DEFAULT NULL,
"trae_weight" real(10,3) DEFAULT '0.000',
"driver" TEXT(255) DEFAULT NULL,
"driver_mobile" TEXT(255) DEFAULT NULL,
"driver_idnumber" TEXT(255) DEFAULT NULL,
PRIMARY KEY ("id" ASC)
)
;
第一步 在Nuget中 引入 Sqlite的库。
的代码中引入 命名空间
using System.Data;
using Microsoft.Data.Sqlite;第二步 连接Sqlite。
构建连接字符串
/// <summary>
///
/// </summary>
/// <param name="file">sqlite databases file </param>
/// <returns></returns>
private static string GetConnString(string file)
{
var connStr = new SqliteConnectionStringBuilder()
{
DataSource = file,
Pooling = true,
// 注意 Mode的值 ， SqliteOpenMode.ReadWriteCreate表示不存在文件时
//会自动创建
Mode = SqliteOpenMode.ReadWriteCreate,
}.ConnectionString;
return connStr;
}连接
public bool Connection()
{
bool res = false;
//db file is not exist,
using (SqliteConnection connection = new SqliteConnection(GetConnString(dbfile)))
{
if (connection.State != ConnectionState.Open)
{
connection.Open();
res = connection.State == ConnectionState.Open;
}
}
return res;
}第三步 使用。
添加数据
//各添加10万条数
private void InsertBtn_Click(object sender, RoutedEventArgs e)
{
int total = 100000;
for (int i = 0; i < total; i++)
{
Marteral m = new Marteral()
{
id = i+1,
name = "原煤"+i,
firstCase = "YM"+i,
};
int res = -1;
if(i% 2 == 0)
{
string sql = SqlBuilder.GetInsertSql(m);
res = SqliteHelper.Instance.Insert(sql);
}
else
{
res = SqliteHelper.Instance.Insert(m);
}
if(res >= 0)
{
Debug.WriteLine($"{m.name} inseert successed;");
}
else
{
Debug.WriteLine($"{m.name} inseert errored;");
}
}
for (int i = 0; i < total; i++)
{
Car c= new Car()
{
id = i+1,
carNumber = "云DDD73" + i,
driver = "驾驶员" + i,
driverMobile = "1580874631" +i,
};
int res = -1;
if (i % 2 == 0)
{
string sql = SqlBuilder.GetInsertSql(c);
res = SqliteHelper.Instance.Insert(sql);
}
else
{
res = SqliteHelper.Instance.Insert(c);
}
if (res >= 0)
{
Debug.WriteLine($"{c.carNumber} inseert successed;");
}
else
{
Debug.WriteLine($"{c.carNumber} inseert errored;");
}
}
}修改数据
private void UpdateBtn_Click(object sender, RoutedEventArgs e)
{
for (int i = 0; i < 5; i++)
{
Marteral m = new Marteral()
{
id = i + 1,
name = "精煤煤" + i,
firstCase = "JM" + i,
};
int res = -1;
if (i % 2 == 0)
{
string sql = SqlBuilder.GetUpdateSql(m);
res = SqliteHelper.Instance.Update(sql);
}
else
{
res = SqliteHelper.Instance.Update(m);
}
if (res >= 0)
{
Debug.WriteLine($"{m.name} Update successed;");
}
else
{
Debug.WriteLine($"{m.name} Update errored;");
}
}
for (int i = 0; i < 5; i++)
{
Car c = new Car()
{
id = i + 1,
carNumber = "云AAA73" + i,
driver = "驾驶员" + i,
driverMobile = "1580874631" + i,
};
int res = -1;
if (i % 2 == 0)
{
string sql = SqlBuilder.GetUpdateSql(c);
res = SqliteHelper.Instance.Update(sql);
}
else
{
res = SqliteHelper.Instance.Update(c);
}
if (res >= 0)
{
Debug.WriteLine($"{c.carNumber} Update successed;");
}
else
{
Debug.WriteLine($"{c.carNumber} Update errored;");
}
}
}
删除数据
// id % 2 == 0 的数据删除
private void DeleteBtn_Click(object sender, RoutedEventArgs e)
{
for (int i = 0; i < 5; i++)
{
Marteral m = new Marteral()
{
id = i + 1,
name = "精煤煤" + i,
firstCase = "JM" + i,
};
int res = -1;
if (i % 2 == 0)
{
string sql = SqlBuilder.GetDeleteSql(m);
res = SqliteHelper.Instance.Delete(sql);
}
if (res >= 0)
{
Debug.WriteLine($"{m.name} Delete successed;");
}
else
{
Debug.WriteLine($"{m.name} Delete errored;");
}
}
for (int i = 0; i < 5; i++)
{
Car c = new Car()
{
id = i + 1,
carNumber = "云AAA73" + i,
driver = "驾驶员" + i,
driverMobile = "1580874631" + i,
};
int res = -1;
if (i % 2 == 0)
{
string sql = SqlBuilder.GetDeleteSql(c);
res = SqliteHelper.Instance.Delete(sql);
}
if (res >= 0)
{
Debug.WriteLine($"{c.carNumber} Delete successed;");
}
else
{
Debug.WriteLine($"{c.carNumber} Delete errored;");
}
}
}
查询并在日志在打印内容
private void SelectBtn_Click(object sender, RoutedEventArgs e)
{
string sql = SqlBuilder.GetSelectSql("car", "", "");
List<Car> cars = SqliteHelper.Instance.Select<Car>(sql);
cars.ForEach((c) => { Debug.WriteLine(c.carNumber+" trae:"+c.traeWeight); });
string sql2 = SqlBuilder.GetSelectSql("marteral", "", "");
List<Marteral> ms = SqliteHelper.Instance.Select<Marteral>(sql2);
ms.ForEach((m) => { Debug.WriteLine(m.name); });
}
最后
代码仓库：sqlite_demo: C# WPF 桌面应用程序，数据存储使用Sqlite ，这是一个数据基本操作的基本Demo
感谢各位朋友的阅读，有不足之处，望指正。
