FreeSql （十二）更新数据时指定列
static IFreeSql fsql = new FreeSql.FreeSqlBuilder()
.UseConnectionString(FreeSql.DataType.MySql, connectionString)
.UseAutoSyncStructure(true) //自动同步实体结构到数据库
.Build(); //请务必定义成 Singleton 单例模式
class Topic {
[Column(IsIdentity = true, IsPrimary = true)]
public int Id { get; set; }
public int Clicks { get; set; }
public string Title { get; set; }
public DateTime CreateTime { get; set; }
}
更新指定列
fsql.Update<Topic>(1)
.Set(a => a.CreateTime, DateTime.Now)
.ExecuteAffrows();
//UPDATE `Topic` SET `CreateTime` = '2018-12-08 00:04:59'
//WHERE (`Id` = 1)
支持 Set() 多次，相当于拼接
更新指定列，累加
fsql.Update<Topic>(1)
.Set(a => a.Clicks + 1)
.Set(a => a.Time == DateTime.Now)
.ExecuteAffrows();
//UPDATE `Topic` SET `Clicks` = ifnull(`Clicks`,0) + 1, `Time` = now()
//WHERE (`Id` = 1)
更新指定列，一次指定
fsql.Update<Topic>(1)
.Set(a => new Topic
{
Clicks = a.Clicks + 1,
Time = DateTime.Now
})
.ExecuteAffrows();
//UPDATE `Topic` SET `Clicks` = ifnull(`Clicks`,0) + 1, `Time` = now()
//WHERE (`Id` = 1)
根据 Dto 更新
fsql.Update<T>()
.SetDto(new { title = "xxx", clicks = 2 })
.Where(a => a.Id == 1)
.ExecuteAffrows();
//UPDATE `Topic` SET `Title` = @p_0, `Clicks` = @p_1
//WHERE (Id = 1)
fsql.Update<T>()
.SetDto(new Dictionary<string, object> { ["title"] = "xxx", ["clicks"] = 2 })
.Where(a => a.Id == 1)
.ExecuteAffrows();
//效果同上
自定义SQL
fsql.Update<Topic>()
.SetRaw("Title = @title", new { title = "新标题" })
.Where("Id = @id", 1)
.ExecuteAffrows();
//UPDATE `Topic` SET Title = @title WHERE (Id = @id)
API
| 方法 | 返回值 | 参数 | 描述 |
|---|---|---|---|
| SetSource | <this> | T1 | IEnumerable |
更新数据，设置更新的实体 |
| Set | <this> | Lambda, value | 设置列的新值，Set(a => a.Name, "newvalue") |
| Set | <this> | Lambda | 设置列的的新值为基础上增加，Set(a => a.Clicks + 1)，相当于 clicks=clicks+1 |
| SetDto | <this> | object | 根据 dto 更新的方法 |
| SetRaw | <this> | string, parms | 设置值，自定义SQL语法，SetRaw("title = @title", new { title = "newtitle" }) |
| Where | <this> | Lambda | 表达式条件，仅支持实体基础成员（不包含导航对象） |
| Where | <this> | string, parms | 原生sql语法条件，Where("id = @id", new { id = 1 }) |
| Where | <this> | T1 | IEnumerable |
传入实体或集合，将其主键作为条件 |
| WhereExists | <this> | ISelect | 子查询是否存在 |
| CommandTimeout | <this> | int | 命令超时设置(秒) |
| WithTransaction | <this> | DbTransaction | 设置事务对象 |
| WithConnection | <this> | DbConnection | 设置连接对象 |
| ToSql | string | 返回即将执行的SQL语句 | |
| 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 |
系列文章导航
-
（十二）更新数据时指定列
