Basic use of Dapper.extension

Objective

The previous essay wrote the simple use of dapper, This time to write about the use of dapper.extension, it is a simple package extension of dapper, can be instantiated by the object assignment after the operation of adding and removing, and paging, but can not do multi-table query operation, this needs to expand it yourself. The operation of the transaction is the same as the dapper.

1. Get a single entity　　

　　This is a straightforward pass-through ID to get the returned object, as follows:

 public   Student Extget () {  using  (IDbConnection conn = new  Span style= "COLOR: #000000" > SqlConnection (SqlConnection)) { return  Conn. Get<student> (1 ); //  here can only pass ID query, and Student fields must match the table field, one less one will be an error. So getting a single object feels like a dapper native statement. Good  
   
    // 
    return Conn. Get<student> ("Select Id,score,courseid,studentid from Student where id = 1");  
    // 
     }}  
   

2. Get multiple Entities List

The specific code and comments are as follows:

         PublicList<student>extlist () {using(IDbConnection conn =NewSqlConnection (SqlConnection)) {IList<ISort> sortlist =NewList<isort>(); Sortlist. ADD (NewSort {propertyname ="ID", ascending =false});//Sorting CriteriaIList<IPredicate> prelist =NewList<ipredicate>(); Prelist.add (Predicates.field<Student> (o = o.id, Operator.eq,2));//search criteria, there are many types of operator such as EQ equals, like usage for SQL and LT, Le, etc.betweenvalues betweenvalues=NewBetweenvalues ();//search criteria, between search for data between two valuesBetweenvalues.value1 =1; Betweenvalues.value2=6; Prelist.add (Predicates.between<Student> (o =o.id, betweenvalues)); varSubpre = predicates.field<student> (o = o.id, Operator.eq,3);//search criteria to determine if a condition exists, followed by a Boolean argument if True indicates not present, false is presentPrelist.add (predicates.exists<student> (Subpre,true)); Prelist.add (Predicates.property<Student,Student> (o = o.id, operator.eq, t = t.id));//determine the relationship of two fields, such as whether equal, greater than, less than, and field is similar, and can not be used for two table field judgmentIpredicategroup Predgroup= Predicates.group (groupoperator.or, Prelist.toarray ());//confirm how multiple search conditions are connected and or                varList = conn. Getlist<student> (Predgroup, sortlist). Tolist<student>(); returnlist; //the SQL statements generated by the above code are as follows//exec sp_executesql N ' SELECT [Student]. [id], [Student]. [Name], [Student]. [Sex], [Student]. [Tel] From [Student]//WHERE ([student].[ ID] = @id_0)//OR//([student].[ ID] between @id_1 and @id_2)//OR//(Not EXISTS (SELECT 1 from [Student] WHERE ([student].[ ID] = @id_3 )))//OR//([student].[ ID] = [Student]. [id]))//ORDER by [Student]. [id] DESC ', N ' @id_0 int, @id_1 int, @id_2 int, @id_3 int ', @id_0 =2, @id_1 =1, @id_2 =6, @id_3 =3            }        }

3. Paging

Pagination specific and GetList method is the same, just a number of page numbers and data per page parameters, the specific code is as follows:

         PublicList<student>extpagelist () {using(IDbConnection conn =NewSqlConnection (SqlConnection)) {IList<ISort> sortlist =NewList<isort>(); Sortlist. ADD (NewSort {propertyname ="ID", ascending =false});//Sorting CriteriaIList<IPredicate> prelist =NewList<ipredicate>(); Prelist.add (Predicates.field<Student> (o = o.id, Operator.eq,2)); Ipredicategroup Predgroup=Predicates.group (groupoperator.or, Prelist.toarray ()); returnConn. Getpage<student> (Predgroup,sortlist,1,Ten).            ToList (); }        }

4. Add

        /// <summary>        ///added, can only be added individually///by passing in the assembled class object, you can insert the data///If no data is null or is the default value for a database field/// </summary>         Public voidExtadd () {using(IDbConnection conn =NewSqlConnection (SqlConnection)) {Student Student=NewStudent (); Student.name="Test Students"; Student.sex=1; //student.tel= "13222222222";                intID = conn. Insert<student> (Student);//returns the self-increment primary key ID            }        }

5. Update

        /// <summary>        ///updates, only single updates///If a field is not assigned, it causes the database field to be updated to null.///so it's important to keep the data intact./// </summary>         Public voidextupdate () {using(IDbConnection conn =NewSqlConnection (SqlConnection)) {Student Student=NewStudent (); Student.id=1013; Student.name="Test Students"; Student.sex=1; //student.tel= "13222222222";                if(Conn. Update<student>(student)) {                    //Success                }                Else                 {                    //failed                }            }        }

6. Delete

        /// <summary>        ///Delete, only single delete///this way, you can specify the criteria for deletion by passing in an ID entity or predicates object .///predicates words and list that part of the operation is the same, you can refer to the extlist kind of detailed use/// </summary>         Public voidExtdel () {using(IDbConnection conn =NewSqlConnection (SqlConnection)) {Student Student=NewStudent (); Student.id=1020; varPre = predicates.field<student> (o = o.id, Operator.eq,1017); if(Conn. Delete<student> (Student))//or Conn. Delete<student> (PRE)                {                    //Success                }                Else                 {                    //failed                }            }        }

Basic use of Dapper.extension