开篇语
本文主要是回顾下从项目创建到生成数据到数据库(代码优先)的全部过程。采用efcore作为orm框架。
本次示例环境：vs2019、net5、mysql
创建项目
本次事例代码是用过vs2019创建的asp.net core web api项目
可以通过可视化界面创建或者通过命令行创建
dotnet new webapi -o net5bydocker
创建实体类
安装组件
<packagereference include="pomelo.entityframeworkcore.mysql" version="5.0.0" />
<packagereference include="pomelo.entityframeworkcore.mysql.json.newtonsoft" version="5.0.0" />
增加实体类
[table("user")]
public class user
{
public user()
{
id = guid.newguid().tostring();
}
public user(string account, string password, string creater) : this()
{
account = account;
password = password;
deleted = false;
setcreater(creater);
}
[key]
[comment("主键")]
[stringlength(36)]
[required]
public string id { get; private set; }
[comment("帐号")]
[stringlength(36)]
[required]
public string account { get; private set; }
[comment("密码")]
[stringlength(36)]
[required]
public string password { get; private set; }
[comment("余额")]
[column(typename = "decimal(18, 2)")]
[required]
public decimal money { get; set; }
[comment("是否删除")]
[column(typename = "tinyint(1)")]
[required]
public bool deleted { get; private set; }
[comment("创建人")]
[stringlength(20)]
[required]
public string creater { get; private set; }
[comment("创建时间")]
[required]
public datetime createtime { get; private set; }
[comment("修改人")]
[stringlength(20)]
[required]
public string modifyer { get; private set; }
[comment("修改时间")]
[required]
public datetime modifytime { get; private set; }
public void setcreater(string name)
{
creater = name;
createtime = datetime.now;
setmodifyer(name);
}
public void setmodifyer(string name)
{
modifyer = name;
modifytime = datetime.now;
}
}
这种只是增加实体类类型的一种方式，可能这种看着比较乱，还可以通过onmodelcreating实现，详情看参考文档
增加数据库上下文opendbcontext
public class opendbcontext : dbcontext
{
public opendbcontext(dbcontextoptions<opendbcontext> options)
: base(options)
{
}
public dbset<user> users { get; set; }
}
startup注入连接数据库操作
var connection = configuration["dbconfig:mysql:connectionstring"];
var migrationsassembly = introspectionextensions.gettypeinfo(typeof(startup)).assembly.getname().name;
services.adddbcontext<opendbcontext>(option => option.usemysql(connection, serverversion.autodetect(connection), x =>
{
x.usenewtonsoftjson();
x.migrationsassembly(migrationsassembly);
}));
生成迁移文件
引用组件
<packagereference include="microsoft.entityframeworkcore.design" version="5.0.5"> <packagereference include="microsoft.entityframeworkcore.tools" version="5.0.5">
迁移命令
add-migration init
结果
要看下生成的迁移文件是否是自己预期的那样子，也可以在这一步就生成数据库，命令：update-database
数据种子
增加opendbsend类，添加数据种子
public class opendbsend
{
/// <summary>
/// 生成数据库以及数据种子
/// </summary>
/// <param name="dbcontext">数据库上下文</param>
/// <param name="loggerfactory">日志</param>
/// <param name="retry">重试次数</param>
/// <returns></returns>
public static async task seedasync(opendbcontext dbcontext,
iloggerfactory loggerfactory,
int? retry = 0)
{
int retryforavailability = retry.value;
try
{
dbcontext.database.migrate();//如果当前数据库不存在按照当前 model 创建，如果存在则将数据库调整到和当前 model 匹配
await initializeasync(dbcontext).configureawait(false);
//if (dbcontext.database.ensurecreated())//如果当前数据库不存在按照当前 model创建，如果存在则不管了。
// await initializeasync(dbcontext).configureawait(false);
}
catch (exception ex)
{
if (retryforavailability < 3)
{
retryforavailability++;
var log = loggerfactory.createlogger<opendbsend>();
log.logerror(ex.message);
await seedasync(dbcontext, loggerfactory, retryforavailability).configureawait(false);
}
}
}
/// <summary>
/// 初始化数据
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public static async task initializeasync(opendbcontext context)
{
if (!context.set<user>().any())
{
await context.set<user>().addasync(new user("azrng", "123456", "azrng")).configureawait(false);
await context.set<user>().addasync(new user("张三", "123456", "azrng")).configureawait(false);
}
await context.savechangesasync().configureawait(false);
}
}
设置项目启动时候调用
public static async task main(string[] args)
{
var host = createhostbuilder(args).build();
using (var scope = host.services.createscope())
{
var services = scope.serviceprovider;
var loggerfactory = services.getrequiredservice<iloggerfactory>();
var _logger = loggerfactory.createlogger<program>();
try
{
var opencontext = services.getrequiredservice<opendbcontext>();
await opendbsend.seedasync(opencontext, loggerfactory).configureawait(false);
}
catch (exception ex)
{
_logger.logerror(ex, $"项目启动出错 {ex.message}");
}
}
await host.runasync().configureawait(false);
}
生成数据库
启动项目，自动生成数据库
表结构如下
如果后期数据库字段或者结构有变动，可以再次生成迁移文件然后生成数据库
查询数据
/// <summary>
/// 用户接口
/// </summary>
public interface iuserservice
{
string getname();
/// <summary>
/// 查询用户信息
/// </summary>
/// <param name="account"></param>
/// <returns></returns>
task<user> getdetailsasync(string account);
}
/// <summary>
/// 用户实现
/// </summary>
public class userservice : iuserservice
{
private readonly opendbcontext _dbcontext;
public userservice(opendbcontext dbcontext)
{
_dbcontext = dbcontext;
}
public string getname()
{
return "azrng";
}
///<inheritdoc cref="iuserservice.getdetailsasync(string)"/>
public async task<user> getdetailsasync(string account)
{
return await _dbcontext.set<user>().firstordefaultasync(t => t.account == account).configureawait(false);
}
}
一般更推荐建立指定的返回model类，然后只查询需要的内容，不直接返回实体类
控制器方法
/// <summary>
/// 查询用户详情
/// </summary>
/// <param name="account"></param>
/// <returns></returns>
[httpget]
public async task<actionresult<user>> getdetailsasync(string account)
{
return await _userservice.getdetailsasync(account).configureawait(false);
}
查询结果
{
"id": "e8976d0a-6ee9-4e2e-b8d8-1fe6e85b727b",
"account": "azrng",
"password": "123456",
"money": 0,
"deleted": false,
"creater": "azrng",
"createtime": "2021-05-09t15:48:45.730302",
"modifyer": "azrng",
"modifytime": "2021-05-09t15:48:45.730425"
}
参考文档
实体类型：
实体属性：https://docs.microsoft.com/zh-cn/ef/core/modeling/entity-properties?tabs=data-annotations%2cwithout-nrt
到此这篇关于.net之生成数据库全流程实现的文章就介绍到这了,更多相关.net 生成数据库内容请搜索www.887551.com以前的文章或继续浏览下面的相关文章希望大家以后多多支持www.887551.com！
黄山市民网：https://www.huangshanshimin.com/
