C# WPF 桌面应用程序使用 SQlite 数据库

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); });}