摘要：
时间短，水平有限。如果有什么问题，请改正。
EF版本：6.0.0
EF对大量数据或多表连接一次操作耗时较大，或要求响应时间尽可能小，因此采用EF框架执行SQL语句的方案
1DbContext.Database
这个类包含了大量的操作方法，见截图：
查询方法举例：
using (CustomDbContext db = newCustomDbContext()) { string sql = "SELECT * FROM collections LEFT JOIN collectionusers ON collections.`Id`=collectionusers.`Collection_Id`"; var task = db.Database.SqlQuery<Collection>(sql).ToListAsync(); task.Wait(); var r =task.Result; }
删除方法举例：
using (CustomDbContext db = newCustomDbContext()) { string sql = "delete from collectionusers where Id=@id"; var num = db.Database.ExecuteSqlCommand(sql, new MySqlParameter("@id", 322)); }
注意操作Mysql数据库，一定要是有MySqlParameter而不能使用SqlParameter，使用SqlParameter会抛出异常：Only MySqlParameter objects may be stored
更新方法举例：
using (CustomDbContext db = newCustomDbContext()) { string sql = "update collectionusers set InsertTime=@time where Id=@id"; var num = db.Database.ExecuteSqlCommand(sql, new MySqlParameter("@time", DateTime.Now),new MySqlParameter("@id", 323)); }
插入方法举例：
using (CustomDbContext db = newCustomDbContext()) { db.Database.ExecuteSqlCommand("SET SQL_SAFE_UPDATES=0");//不启用更新安全模式 db.Database.ExecuteSqlCommand("SET FOREIGN_KEY_CHECKS=0");//取消外键约束 string sql = "INSERT INTO collectionusers (`InsertTime`, `Collection_Id`, `User_Id`)VALUES(@insertTime,@cid, @uid)"; var num = db.Database.ExecuteSqlCommand(sql, new MySqlParameter("@insertTime", DateTime.Now), new MySqlParameter("@cid", 11), new MySqlParameter("@uid",22)); }
事务操作举例：
CustomDbContext db = null; DbContextTransaction tran = null; try{ db = newCustomDbContext(); tran =db.Database.BeginTransaction(); db.Database.ExecuteSqlCommand("SET SQL_SAFE_UPDATES=0");//不启用更新安全模式 db.Database.ExecuteSqlCommand("SET FOREIGN_KEY_CHECKS=0");//取消外键约束 string sql = "INSERT INTO collectionusers (`InsertTime`, `Collection_Id`, `User_Id`)VALUES(@insertTime,@cid, @uid)"; var num = db.Database.ExecuteSqlCommand(sql, new MySqlParameter("@insertTime", DateTime.Now), new MySqlParameter("@cid", 11), new MySqlParameter("@uid", 22)); tran.Commit(); } catch{ tran.Rollback(); } finally{ if (db != null) db.Dispose(); if (tran != null) tran.Dispose(); }
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转载与引用请注明出处。
时间仓促，水平有限，如有不当之处，欢迎指正。