使用LINQ从linq对象编写SQL查询列表

Question

我有一个linq对象，我想用linq编写查询。

请帮帮我。

输入：

var tags = (from row in tempChildData.AsEnumerable() 
           join tagOrder in tupleInfoDataset.Tables["TagHierarchy"].AsEnumerable() on row.Field<Int64>("TAGID") equals tagOrder.Field<Int64>("TAGID") 
           join tagName in tupleInfoDataset.Tables["SequenceChoiceList"].AsEnumerable() on tagOrder.Field<Int64>("PARENTTAGID") equals tagName.Field<Int64>("TAGID") 
           join facet in tupleInfoDataset.Tables["FacetType"].AsEnumerable() on tagName.Field<string>("Tag_Name") equals facet.Field<string>("Facetname") 
           join tagIdInfo in schDataTogetTagid.AsEnumerable() on row.Field<string>("refTagName").Contains(":") ? row.Field<string>("refTagName").Split(':').Last():row.Field<string>("refTagName") equals tagIdInfo.Field<string>("TAGNAME") 
           where (childList.Contains(row.Field<Int64>("TAGID")) && facet.Field<string>("FacetType").ToLower().Equals("ctype")) 
           select new 
           { 
            Tagid = row.Field<Int64>("TAGID"), 
            TagIdToInsert=tagIdInfo.Field<Int64>("TAGID"), 
            MaxOccur = row.Field<string>("Maxoccurs"), 
            MinOccur =Convert.ToInt32(Convert.ToString(row.Field<string>("Minoccur"))), 
            ParentTagId=tagOrder.Field<Int64>("PARENTTAGID"), 
            Order=tagOrder.Field<Int64>("TAG_ORDER"), 
            ParentTagname = tagName.Field<string>("Tag_Name"), 
            FacetId=facet.Field<Int64>("FacetID") 
           }).ToList(); 


        var parentTagID = (from tagIdInfo in tupleInfoDataset.Tables["Tuple"].AsEnumerable() 
             where tagIdInfo.Field<Int64>("TAGID").Equals(key.Key) 
             select tagIdInfo.Field<Int64>("ConceptID")).ToList(); 
        long parentID =Convert.ToInt64(parentTagID[0]); 

现在我想查询出上面的代码为：

INSERT INTO TUPLE_MAP (TagId,ParentTagId,ParentTagname,MinOccur,MaxOccur,Order) 
VALUES (TagIdToInsert,ParentTagId,ParentTagname,MinOccur,MaxOccur,Order) 

请帮助我，我不知道如何使用LINQ

Answer 1

也许是这样的：

using(var db=new DataContext("YourConnectionStringHERE")) 
{ 
    db.TUPLE_MAP.InsertAllOnSubmit(tags.Select (t => 
    new TUPLE_MAP() 
    { 
     TagId=t.TagIdToInsert, 
     ParentTagId=t.ParentTagId, 
     ParentTagname=t.ParentTagname, 
     MinOccur=t.MinOccur, 
     MaxOccur=t.MaxOccur, 
     Order=t.Order 
    })); 
    db.SubmitChanges(); 
} 

或者，如果你想使用parentID则是这样的：

using(var db=new DataContext("YourConnectionStringHERE")) 
{ 
    db.TUPLE_MAP.InsertAllOnSubmit(tags.Select (t => 
    new TUPLE_MAP() 
    { 
     TagId=t.TagIdToInsert, 
     ParentTagId=parentID, 
     ParentTagname=t.ParentTagname, 
     MinOccur=t.MinOccur, 
     MaxOccur=t.MaxOccur, 
     Order=t.Order 
    })); 
    db.SubmitChanges(); 
} 

其中db是您的LINQ数据上下文

有用引用：

• How to: Insert Rows Into the Database (LINQ to SQL)

编辑

因此，如果您使用的是紧凑型数据库3.5那么很多这样的事情：

using (var conn =new SqlCeConnection("Data Source = test.sdf; Password ='pass'")) 
{ 
     foreach (var tag in tags) 
     { 
      using(var cmd = conn.CreateCommand()) 
      { 

       cmd.CommandText = @"INSERT INTO TUPLE_MAP (TagId,ParentTagId,ParentTagname,MinOccur,MaxOccur,Order) 
            VALUES (@TagIdToInsert,@ParentTagId,@ParentTagname,@MinOccur,@MaxOccur,@Order)"; 

       cmd.Parameters.AddWithValue("@TagIdToInsert", tag.TagIdToInsert); 
       cmd.Parameters.AddWithValue("@ParentTagId", tag.ParentTagId); 
       cmd.Parameters.AddWithValue("@ParentTagname", tag.ParentTagname); 
       cmd.Parameters.AddWithValue("@MinOccur", tag.MinOccur); 
       cmd.Parameters.AddWithValue("@MaxOccur", tag.MaxOccur); 
       cmd.Parameters.AddWithValue("@Order", tag.Order); 

       cmd.ExecuteNonQuery(); 

      } 
     } 
    } 

有用的参考资料：

• Why can't I insert a record into my SQL Compact 3.5 database?
• SqlCeCommand.Parameters Property
• SqlCeCommand Class
• SqlParameterCollection.AddWithValue Method

Answer 2

写SQL查询

使用linq Pad或sql分析器查看生成的SQL。 您也可以为此使用visual studio。在调试模式下，将光标放在变量“标签”上，您将能够看到SQL。

Answer 3

我假设你正在使用Linq to SQL，如果你这样做，你会在你的xxxDataContext中有一个名为Tuple_map的实体。然后，你就只需要创建的该实体是这样的对象....

using (XXXDataContext context = new XXXDataContext()) 
{ 
    Tuple_map obj = new Tuple_map(); 
    //Populate obj properties like obj.tabid = from objects you got it from above query 
    context.Tuple_map.InsertOnSubmit(obj); 
    context.SubmitChanges(); 
}