ado.net

问题 I have created textbox and label dynamically, which can automatically increased if I increase the rows of the database. But now I want to insert or update values into textbox to store data in the database. Here is my code... string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString; using (SqlConnection con = new SqlConnection(cs)) { //string cmText = "select ProductId,ProductName,UnitPrice from tblProduct"; string cmText = "Select Count(ProductId) from tblProduct";

问题 The application uses ADO.NET to invoke sprocs for nearly every database operation. Some of these sprocs also contain a fair amount of domain logic. The data access logic for each domain entity resides in the domain class itself. ie, there is no decoupling between domain logic and data access logic. I'm looking to accomplish the following: decouple the domain logic from the data access logic make the domain model persistence ignorant implement the transition to NHibernate gradually across

问题 I have 2 project in my .net solution.each one has entity data model.how I can make an association between two entities one in the first project data model while the other in the second project data model in the same solution? what if each data model mapped to different database? 回答1: As far as I know you can't achieve this within a reasonable solution. 回答2: It is impossible to have a database relation between two fields in separate databases, however, you can do this of course with server

问题 When creating an SqlParameter (.NET3.5) or OdbcParameter , I often use the SqlParameter(string parameterName, Object value) constructor overload to set the value in one statement. However, when I tried passing a literal 0 as the value parameter, I was initially caught by the C# compiler choosing the (string, OdbcType) overload instead of (string, Object) . MSDN actually warns about this gotcha in the remarks section, but the explanation confuses me. Why does the C# compiler decide that a

问题 EDIT: I came across an old question that has my problem. Entity Framework conflict with same table name from different databases one of the solutions is using Code first for an existing database and change the namespace. I did use the code first and the generated classes were missing the LOB class. please guys, any ideas what to do? I'm trying to add multiple databases to my project. when I tried to add the second database using the ADO.net model .the generated context class of the first

问题 EDIT: I came across an old question that has my problem. Entity Framework conflict with same table name from different databases one of the solutions is using Code first for an existing database and change the namespace. I did use the code first and the generated classes were missing the LOB class. please guys, any ideas what to do? I'm trying to add multiple databases to my project. when I tried to add the second database using the ADO.net model .the generated context class of the first

问题 EDIT: I came across an old question that has my problem. Entity Framework conflict with same table name from different databases one of the solutions is using Code first for an existing database and change the namespace. I did use the code first and the generated classes were missing the LOB class. please guys, any ideas what to do? I'm trying to add multiple databases to my project. when I tried to add the second database using the ADO.net model .the generated context class of the first

问题 My code reads via one connection and writes via another. I dont want to accidentally write with the read connection. How can i make the connection readonly? I am using SQLite ATM and will convert sections of code to tsql when the prototype is over. 回答1: You can add Read Only=True to the read-only connection. Data Source=filename;Read Only=True; 来源： https://stackoverflow.com/questions/2004010/readonly-connections-with-ado-net-sqlite-and-tsql

问题 Suppose that I have an ASP.NET page. In the page load event handler, I open a database connection and do some processing. But after the processing is done, I don't close the connection explicitly by calling the CLOSE method of the connection object. Now when the page processing at the server side is finished, the GC will dispose all the variables in my page, and also, the connection object too. But when it is disposed, does the connection that was opened previously is automatically closed? I

问题 I'm building an interface layer for a Matlab component which is used to analyse data maintained by a separate .NET application which I am also building. I'm trying to serialise a .NET datatable as a numeric array to be passed to the MATLAB component (as part of a more generalised serialisation routine). So far, I've been reasonably successful with passing tables of numeric data but I've hit a snag when trying to add a column of datatype DateTime . What I've been doing up to now is stuffing