FreeSql

打造 .NETCore 最方便的orm，dbfirst codefirst混合使用，codefirst模式下的开发阶段，建好实体不用执行任何，就能创建表和修改字段，dbfirst模式下提供api+模板，自定义生成代码，作者提供了3种模板。

• 《CodeFirst 快速开发文档》

• 《DbFirst 快速开发文档》

快速开始

var connstr = "Data Source=127.0.0.1;Port=3306;User ID=root;Password=root;" + 
    "Initial Catalog=cccddd;Charset=utf8;SslMode=none;Max pool size=10";

IFreeSql fsql = new FreeSql.FreeSqlBuilder()
    .UseConnectionString(FreeSql.DataType.MySql, connstr)
    .UseSlave("connectionString1", "connectionString2") //使用从数据库，支持多个

    .UseLogger(null) //使用日志，不指定默认输出控制台 ILogger
    .UseCache(null) //使用缓存，不指定默认使用内存 IDistributedCache

    .UseAutoSyncStructure(true) //自动同步实体结构到数据库
    .UseSyncStructureToLower(true) //转小写同步结构
    .Build();

实体

[Table(Name = "tb_topic")]
class Topic {
    [Column(IsIdentity = true)]
    public int Id { get; set; }
    public int Clicks { get; set; }
    public string Title { get; set; }
    public DateTime CreateTime { get; set; }

    public int TypeId { get; set; }
    public TopicType Type { get; set; } //导航属性
}
class TopicType {
    [Column(IsIdentity = true)]
    public int Id { get; set; }
    public string Name { get; set; }

    public int ClassId { get; set; }
    public TopicTypeClass Class { get; set; } //导航属性
}
class TopicTypeClass {
    public int Id { get; set; }
    public string Name { get; set; }
}

Part1: 查询

List<Topic> t1 = fsql.Select<Topic>().Where(a => a.Id > 0).ToList();

//返回普通字段 + 导航对象 Type 的数据
List<Topic> t2 = fsql.Select<Topic>().LeftJoin(a => a.Type.Id == a.TypeId).ToList();

//返回一个字段
List<int> t3 = fsql.Select<Topic>().Where(a => a.Id > 0).ToList(a => a.Id);

//返回匿名类型
List<匿名类型> t4 = fsql.Select<Topic>().Where(a => a.Id > 0).ToList(a => new { a.Id, a.Title });

//返回元组
List<(int, string)> t5 = fsql.Select<Topic>().Where(a => a.Id > 0).ToList<(int, string)>("id, title");

联表之一：使用导航属性

sql = fsql.Select<Topic>()
    .LeftJoin(a => a.Type.Id == a.TypeId)
    .ToSql();

sql = fsql.Select<Topic>()
    .LeftJoin(a => a.Type.Id == a.TypeId)
    .LeftJoin(a => a.Type.Class.Id == a.Type.ClassId)
    .ToSql();

联表之二：无导航属性

sql = fsql.Select<Topic>()
    .LeftJoin<TopicType>((a, b) => b.Id == a.TypeId)
    .ToSql();

sql = fsql.Select<Topic>()
    .LeftJoin<TopicType>((a, b) => b.Id == a.TypeId)
    .LeftJoin<TopicTypeClass>((a, c) => c.Id == a.Type.ClassId)
    .ToSql();

联表之三：b, c 条件怎么设？试试这种！

sql = fsql.Select<Topic>()
    .From<TopicType, TopicTypeClass>((s, b, c) => s
    .LeftJoin(a => a.TypeId == b.Id)
    .LeftJoin(a => b.ClassId == c.Id))
    .ToSql();

联表之四：原生SQL联表

sql = fsql.Select<Topic>()
    .LeftJoin("TopicType b on b.Id = a.TypeId and b.Name = ?bname", new { bname = "xxx" })
    .ToSql();

Part2: 添加

var items = new List<Topic>();
for (var a = 0; a < 10; a++)
    items.Add(new Topic { Title = $"newtitle{a}", Clicks = a * 100 });

var t1 = fsql.Insert<Topic>().AppendData(items.First()).ToSql();

//批量插入
var t2 = fsql.Insert<Topic>().AppendData(items).ToSql();

//插入指定的列
var t3 = fsql.Insert<Topic>().AppendData(items)
    .InsertColumns(a => a.Title).ToSql();

var t4 = fsql.Insert<Topic>().AppendData(items)
    .InsertColumns(a => new { a.Title, a.Clicks }).ToSql();

//忽略列
var t5 = fsql.Insert<Topic>().AppendData(items)
    .IgnoreColumns(a => a.CreateTime).ToSql();

var t6 = fsql.Insert<Topic>().AppendData(items)
    .IgnoreColumns(a => new { a.Title, a.CreateTime }).ToSql();

执行命令

方法	返回值	描述
ExecuteAffrows	long	执行SQL语句，返回影响的行数
ExecuteIdentity	long	执行SQL语句，返回自增值
ExecuteInserted	List<Topic>	执行SQL语句，返回插入后的记录

Part3: 修改

var t1 = fsql.Update<Topic>(1).Set(a => a.CreateTime, DateTime.Now).ToSql();
//UPDATE `tb_topic` SET `CreateTime` = '2018-12-08 00:04:59' WHERE (`Id` = 1)

//更新指定列，累加
var t2 = fsql.Update<Topic>(1).Set(a => a.Clicks + 1).ToSql();
//UPDATE `tb_topic` SET `Clicks` = ifnull(`Clicks`,0) + 1 WHERE (`Id` = 1)

//保存实体
var item = new Topic { Id = 1, Title = "newtitle" };
var t3 = fsql.Update<Topic>().SetSource(item).ToSql();
//UPDATE `tb_topic` SET `Clicks` = ?p_0, `Title` = ?p_1, `CreateTime` = ?p_2 WHERE (`Id` = 1)

//忽略列
var t4 = fsql.Update<Topic>().SetSource(item)
    .IgnoreColumns(a => a.Clicks).ToSql();
//UPDATE `tb_topic` SET `Title` = ?p_0, `CreateTime` = ?p_1 WHERE (`Id` = 1)

var t5 = fsql.Update<Topic>().SetSource(item)
    .IgnoreColumns(a => new { a.Clicks, a.CreateTime }).ToSql();
//UPDATE `tb_topic` SET `Title` = ?p_0 WHERE (`Id` = 1)

//批量保存
```csharp
var items = new List<Topic>();
for (var a = 0; a < 10; a++)
    items.Add(new Topic { Id = a + 1, Title = $"newtitle{a}", Clicks = a * 100 });

var t6 = fsql.Update<Topic>().SetSource(items).ToSql();
//UPDATE `tb_topic` SET `Clicks` = CASE `Id` WHEN 1 THEN ?p_0 WHEN 2 THEN ?p_1 
//WHEN 3 THEN ?p_2 WHEN 4 THEN ?p_3 WHEN 5 THEN ?p_4 WHEN 6 THEN ?p_5 WHEN 7 THEN ?p_6 
//WHEN 8 THEN ?p_7 WHEN 9 THEN ?p_8 WHEN 10 THEN ?p_9 END, `Title` = CASE `Id` 
//WHEN 1 THEN ?p_10 WHEN 2 THEN ?p_11 WHEN 3 THEN ?p_12 WHEN 4 THEN ?p_13 WHEN 5 THEN ?p_14 
//WHEN 6 THEN ?p_15 WHEN 7 THEN ?p_16 WHEN 8 THEN ?p_17 WHEN 9 THEN ?p_18 WHEN 10 THEN ?p_19 END, 
//`CreateTime` = CASE `Id` WHEN 1 THEN ?p_20 WHEN 2 THEN ?p_21 WHEN 3 THEN ?p_22 WHEN 4 THEN ?p_23 
//WHEN 5 THEN ?p_24 WHEN 6 THEN ?p_25 WHEN 7 THEN ?p_26 WHEN 8 THEN ?p_27 WHEN 9 THEN ?p_28 
//WHEN 10 THEN ?p_29 END WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))

//批量保存的时候，也可以忽略一些列
var t7 = fsql.Update<Topic>().SetSource(items)
    .IgnoreColumns(a => new { a.Clicks, a.CreateTime }).ToSql();
//UPDATE `tb_topic` SET `Title` = CASE `Id` WHEN 1 THEN ?p_0 WHEN 2 THEN ?p_1 WHEN 3 THEN ?p_2 
//WHEN 4 THEN ?p_3 WHEN 5 THEN ?p_4 WHEN 6 THEN ?p_5 WHEN 7 THEN ?p_6 WHEN 8 THEN ?p_7 WHEN 9 
//THEN ?p_8 WHEN 10 THEN ?p_9 END WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))

//批量更新指定列
var t8 = fsql.Update<Topic>().SetSource(items).Set(a => a.CreateTime, DateTime.Now).ToSql();
//UPDATE `tb_topic` SET `CreateTime` = ?p_0 WHERE (`Id` IN (1,2,3,4,5,6,7,8,9,10))

更新条件

fsql.Update<Topic>(object dywhere)

dywhere 支持

• 主键值
• new[] { 主键值1, 主键值2 }
• Topic对象
• new[] { Topic对象1, Topic对象2 }
• new { id = 1 }

var t9 = fsql.Update<Topic>().Set(a => a.Title, "新标题").Where(a => a.Id == 1).ToSql();
//UPDATE `tb_topic` SET `Title` = '新标题' WHERE (Id = 1)

自定义SQL

var t10 = fsql.Update<Topic>().SetRaw("Title = {0}", "新标题").Where("Id = {0}", 1).ToSql();
//UPDATE `tb_topic` SET Title = '新标题' WHERE (Id = 1)
//sql语法条件，参数使用 {0}，与 string.Format 保持一致，无须加单引号，错误的用法：'{0}'

执行命令

方法	返回值	参数	描述
ExecuteAffrows	long		执行SQL语句，返回影响的行数
ExecuteUpdated	List<T1>		执行SQL语句，返回更新后的记录

Part4: 删除

详情查看：《Delete 删除数据》

Part5: 表达式函数

详情查看：《Expression 表达式函数》

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