TableAdapter.Insert不会插入到数据库表中 [英] TableAdapter.Insert does not insert into the database table
问题描述
几天来，我一直在努力应对dataadapter查询的行为。
我很欣赏克服这一点的提示。
我在Visual Foxpro编程方面积累了相当多的经验。
我喜欢tableadapters的概念，因为我觉得这些代码可以保持代码更具可读性所需的所有行
$用于管理连接的b $ b保留在后台。
我在数据库'Zugriffe'中有这个表，这是项目的一部分：
CREATE TABLE [dbo]。[tabelle1]（
[Id] INT IDENTITY（1 ，1）NOT NULL，
[Inhalt] NCHAR（10）NULL，
PRIMARY KEY CLUSTERED（[Id] ASC）
）;
该表目前包含以下值：
ID Inhalt
2 Test0
3 Test1
4 test2
5 Test4
6 Test5
创建tableadapter'tampelle1TableAdapter'。
在tableadapter中添加插入命令'InsertTesting'：
INSERT INTO tabelle1
;                       （Inhalt）
VALUES       （@Inhalt）; 
SELECT SCOPE_IDENTITY（）
$
将ExecuteMode设置为'Scalar'。
这个运行时执行的代码：
------------------------------------- -------------
//在插入命令之前为表tabelle1中的值创建数据集
ZugriffeDataSet MyDataset = new ZugriffeDataSet（ ）; $
//在插入命令后为表tabelle1中的值创建数据集
ZugriffeDataSet MyDatasetafterit = new ZugriffeDataSet（）;
/ /启动tabelle1TableAdapter的新实例
ZugriffeDataSetTableAdapters.tabelle1TableAdapter MyTableAdapter =
new ZugriffeDataSetTableAdapters.tabelle1TableAdapter（）;
$
//用数据集填充数据集插入命令之前的tabelle1
int nzahlFill = MyTableAdapter.Fill（MyDataset.tabelle1）;
$
//使用tabelle1TableAdapter的标准插入命令上传数据
string MyInhalt =" Erster";
int nzahl = MyTableAdapter.Insert（MyInhalt）;
$
//使用自编码插入命令上传数据
int new_ID = Convert.ToInt32（MyTableAdapter.InsertTesting（" Test6"） ;））; $
//插入符号后填充tabelle1内容的第二个数据集为
int nzahlFill2 = MyTableAdapter.Fill（MyDatasetafterit.tabelle1）;
------------------------------------------------- -----------
发生这种情况：
- nzahl设置为1 =>添加1行
- new_ID设置为8 =>在运行代码之前的最高ID为6.添加了两行：最新ID：8¥
- MyDatasetafterit包含7行，包括刚刚添加的行。
全部按预期进行。
我结束调试并查看tabelle1。令我惊讶的是，我只看到五行。
再次运行代码将得到完全相同的结果，特别是new_ID将再次为8.
为什么我看不到tabelle1中添加的行，如果我能看到MyDatasetafterit中添加的两行？
$
我是否缺少另一个命令来不断将内容上传到tabelle1？
再次感谢。
互联网上有丢失的例子
https://docs.microsoft.com/en-us / dotnet / framework / data / adonet / retrieve--identity-or-autonumber-values
https://www.aspsnippets.com/Articles/Add-Insert-Identity-column-to -DataTable-在-C-和-VBNet.aspx
For days I am struggling with the behavior of dataadapter queries.
A hint to get over this would really be appreciated.
I collected quite some experience in programming Visual Foxpro.
I like the concept of tableadapters, because I think these keep the code more readable as all the lines needed
for the management of the connections is kept in the background.
I do have this table in the database 'Zugriffe', which is part of the project:
CREATE TABLE [dbo].[tabelle1] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[Inhalt] NCHAR (10) NULL,
PRIMARY KEY CLUSTERED ([Id] ASC)
);
The table is currently comprising these values:
ID Inhalt
2 Test0
3 Test1
4 test2
5 Test4
6 Test5
Created the tableadapter 'tabelle1TableAdapter'.
Added the insert command 'InsertTesting' in the tableadapter:
INSERT INTO tabelle1
(Inhalt)
VALUES (@Inhalt);
SELECT SCOPE_IDENTITY()
Set the ExecuteMode to 'Scalar'.
Have this code executed in runtime:
--------------------------------------------------
//Create a dataset for the values in table tabelle1 before the insert commands
ZugriffeDataSet MyDataset = new ZugriffeDataSet();
//Create a dataset for the values in table tabelle1 after the insert commands
ZugriffeDataSet MyDatasetafterit = new ZugriffeDataSet();
//Initiate new instance of tabelle1TableAdapter
ZugriffeDataSetTableAdapters.tabelle1TableAdapter MyTableAdapter =
new ZugriffeDataSetTableAdapters.tabelle1TableAdapter();
//Fill dataset with values out of tabelle1 before insert commands
int nzahlFill = MyTableAdapter.Fill(MyDataset.tabelle1);
//Use standard insert command of tabelle1TableAdapter to upload data
string MyInhalt = "Erster";
int nzahl = MyTableAdapter.Insert(MyInhalt);
//Use self coded insert command to upload data
int new_ID = Convert.ToInt32(MyTableAdapter.InsertTesting("Test6"));
//Fill second dataset with content of tabelle1 after inserting
int nzahlFill2 = MyTableAdapter.Fill(MyDatasetafterit.tabelle1);
------------------------------------------------------------
This is happening:
- nzahl is set to 1 => 1 row is added
- new_ID is set to 8 => highest ID before running the code was 6. Two lines added: Latest ID now: 8
- MyDatasetafterit contains 7 lines including the ones just added
All as expected.
I end the debugging and look into tabelle1. Much to my surprise, I just see five lines.
Running the code again will have the exact same result, in particular, new_ID will be again 8.
Why can't I see the added lines in tabelle1, if I can see the two added lines in MyDatasetafterit?
Am I missing another command to constantly upload the content into tabelle1?
Thanks again.
There are lost of examples on the internet
https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/retrieving-identity-or-autonumber-values
https://www.aspsnippets.com/Articles/Add-Insert-Identity-column-to-DataTable-in-C-and-VBNet.aspx
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