dataset

问题 I have a basic data structure for storing recipes. It consists of three tables as below: Table 1 - Recipes (recipe_id, recipe_name) Table 2 - Ingredients (ingredient_id, ingredient_name) Table 3 - Recipe_Ingredients (recipe_id, ingredient_id) I have come across a problem when adding a new recipe and would like to know the best practice for inserting. Currently, on submitting the form I insert into the Recipes table, the recipe_id is auto generated. I then insert into the Ingredients table,

问题 I have a DataSet with two tables connected by a reference (Loop_id) Table1 Column1 Column2 Loop_id 1 ItemCode_AAA 6 2 ItemCode_BBB 8 Table2 Column1 Loop_id 2014-Sep-09 6 2014-Nov-09 8 How do I retrieve all the columns, except loop_id from both tables to single table. The resulting table should appear like T1_Column1 T1_Column2 T2_Column1 1 ItemCode_AAA 2014-Sep-09 2 ItemCode_BBB 2014-Nov-09 I am using Net Framework 4.5 回答1: Use Linq to DataSets: To enumerate the table, call AsEnumerable .

问题 I am attempting to convert a DataSet to XML and then read it back in a culture-invariant manner. At first this seemed easy, since DataSets use the invariant culture by default. For my first test, I switched to the French locale and verified that the DataSet's WriteXml method used invariant culture settings for doubles. So far, so good. For the second test, I used the Customize Format dialog under Region and Languages to change the decimal symbol to '#' and and negative sign symbol to '~'. To

问题 hoping someone can lend a hand... I am trying to convert JSON to a DataSet, using the below example, but am having problems. I've validated that the JSON is correct, used a method as suggested by Kent. Thanks for your time and help! The following is my JSON: {"jsonData":[{"item1":"one"},{"item2":"two"}]} Here's my webservice C# code: [WebMethod] public string setWorkOrdersUpdated(object jsonData) { try { XmlDocument xd = new XmlDocument(); xd = (XmlDocument)JsonConvert.DeserializeXmlNode

问题 I am retrieving a very large number of records with multiple result sets from SQL Server into my .NET 3.5 project. I can't just pull them all into a DataSet and work on them, since it would take up too much memory. I don't need to pull all the records as once but just one record in the parent table and then the related child records. I could accomplish this with using a DataReader but my concern here is the process of iterating through all the records will take many hours. That means the

问题 hi i have a very simple webform i have a button and a gridview on this form and a dataset that contains linked tables bill, docket, docket_bill etc. On Button click i use the following code protected void button_click(object sender, EventArgs e) { billTableAdapter Billta = new billTableAdapter(); gridview1.datasource = Billta.getTop20Bills(); gridview1.databind()' } Now when i click on the button, i get the following error "Failed to enable constraints. One or more rows contain values

问题 I build up my datagrid with bindnig source: SqlDataAdapter adapter = new SqlDataAdapter(Datenbank.cmd); dataSet1.Tables.Clear(); adapter.Fill(dataSet1, "Table"); bs = new BindingSource(); bs.DataSource = dataSet1.Tables["Table"]; dataGridView1.DataSource = bs; Now I sort grid bs.Sort = "customer DESC"; Now I want to remove row 0 dataSet1.Tables[0].Rows.RemoveAt(0); However, the row which was at position 0 before sorting will be deleted, not the row which now is on position 0 //EDIT : is there

问题 This question is continuation of my previous one. Without going into too much details, I'm filling dataset with 2 related 1-to-many tables. So, my question now is - why this code works good public DataAgencyR_DataSet SelectOne(int id) { DataAgencyR_DataSet result = new DataAgencyR_DataSet(); using (DbCommand command = Connection.CreateCommand()) { try { command.CommandText = SqlStrings.SelectDataAgencyR_SelectOne(); var param = ParametersBuilder.CreateByKey(command, "ID_DeclAgenc", id, "ID

问题 I have a big dataset contains numeric data and in some of its rows there are variable spaces delimiting columns, like: 4 5 6 7 8 9 2 3 4 When I use this line: dataset=numpy.loadtxt("dataset.txt", delimiter=" ") I get this error: ValueError: Wrong number of columns at line 2 How can I change the code to ignore multiple spaces as well? 回答1: The default for delimiter is 'any whitespace'. If you leave loadtxt out, it copes with multiple spaces. >>> from io import StringIO >>> dataset = StringIO('

问题 I setup DataGridView and other UI components to allow user to edit data from SQLite DB. But these changes (even they are properly shows in application) doesn't saves to DB. I have tried this code aBindingSource.EndEdit(); dbDataSetA.GetChanges(); aTableAdapter.Update(dbDataSetA.Accounts); but there are concurrency exception: System.Data.DBConcurrencyException was unhandled Message=Concurrency violation: the UpdateCommand affected 0 of the expected 1 records. So how should I commit