DataSource Controls :: Reading Data From An SQL Query C#?
Feb 26, 2010
I don't know how to read data into variables from a SELECT query. I can add, update, and delete queries with no issues. I have browsed a few books, but everyone uses a different approach. Suppose I want to to run a query and 1 record is returned. How do I get the values into my variables.
Suppose my table name is "Job Orders", and the row returned has these 3 fields:
I have a form with several controls. I'm trying to read from database and navigating through single record per page. I'm displaying a single record but not navigating through. My customerID field is the primarykey. But there are gaps btw records (1,2,5,6,10...etc). Some of them were deleted.
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Dim myReader As SqlDataReader Dim myConnection = New SqlConnection("server=myPCSQLEXPRESS; database=CustomersDB; uid=myPC est; Password=; Trusted_Connection=yes") myConnection.Open() Dim myCommand = New SqlCommand("SELECT * FROM Customers", myConnection) Dim intFirstRecord As Integer = CInt(myCommand.ExecuteScalar()) myReader = myCommand.ExecuteReader() If myReader.Read Then lblCustomerID.Text = myReader("customerID") lblCustomerName.Text = myReader("CustomerName") End If myReader.Close() myConnection.Close() currentRecord = lblCustomerID.Text End Sub
Sub Next_OnClick(ByVal sender As Object, ByVal e As System.EventArgs) Dim myCommand As SqlCommand Dim myConnection As SqlConnection Dim myReader As SqlDataReader myConnection = New SqlConnection("server=myPCSQLEXPRESS; database=CustomersDB; uid=myPC est; Password=; Trusted_Connection=yes") myConnection.Open() myCommand = New SqlCommand("SELECT TOP 1 customerID, CustomerName FROM Customers WHERE customerID > @customerID", myConnection) myCommand.Parameters.Add("@customerID", SqlDbType.Int, 5).Value = currentRecord myReader = myCommand.ExecuteReader()
If myReader.Read Then lblCustomerID.Text = myReader("customerID") lblCustomerName.Text = myReader("CustomerName") End If myReader.Close() myConnection.Close() End Sub
I'm being able to read first record. If I click Next button, my page goes to next record for only once. If i click several times, nothing happens. Does not go to next available records.
1. I have a GridView on my page and it uses sqldatasource with parameterized query. What I want to do is, on page load (where nothing has been selected so no parameter supplied), I want it to query everything (something like SELECT * FROM [this_table]) but since my SelectCommand is something like
SELECT * FROM [this_table] WHERE [this_column] = @someParameters AND [that_column] = @someParameters.
Can I play around with default value to achieve something like that but how ? Now, when the page loads, it doesn't show anything (No Gridview).
2. On my page, I made something like (username, gender, address, and more) and one single search button. That means, no single control enable auto postback. What I am trying to accomplish is building dynamic query
(if username specifed -> SELECT * FROM [this_table] WHERE [username] LIKE @username).
If both username and gender are specified (SELECT * FROM [this_table] WHERE [username] LIKE @username AND [gender] = @gender) and you know the rest. How can I do this using GridView and SqlDataSource ? To my knowledge, I can only specify one SELECT statement in a sqldatasource.
By right clicking on my database i created a query in server explorer. But where are this query stored can't find them back. I should aspect that their is a folder query's like there is a folder tables but this isn't the case.
I need to create a query which does a join between two tables which are in different databases. I can easily connect to each database, and write queries in each, however, I can't seem to find a way of generating a query which does a join between two tables from different databases.
I have a C#/Asp.net web application which caches SQL DB schema information. Is there a way that I can determine what child relationships a given table has? I have looked into using the DataTable.ChildRelations property, but it is never populated with items unless i manually create a relationship using the .add property. I also have access to DataColumn information for each column in the database.
Dim MediaQuery = From m In dB.DOWNLOADS _Where m.ID = id _Select
which returns a record from the database. One of the fields in the record is a FK to another table. I need to read this value to be able to set a dropdown based on the ID but I can't work out how to access it. For a standard record I can just do the following txtTitle.Text = MediaQuery.FirstOrDefault().TITLE
However with the foreign key it doesn't work like that. I've tried drpGroup.SelectedIndex = MediaQuery.FirstOrDefault().DOWNLOAD_GROUPS.ID where DOWNLOAD_GROUPS is the FK field but it returns Object reference not set to an instance of an object. If you're simply wanting to read some values from a single db record in the entitiy framework and one is a foreign key how should I go about getting the value?
string strConString = ConfigurationSettings.AppSettings[ "conString" ]; myConnection = new OdbcConnection(strConString); myConnection.Open(); // open connection string strSelect= "select * from tbl_howells_product_data where title like" + "'" + strsearch + "%" +"'" + "order by product_id asc"; OdbcCommand myCommand = new OdbcCommand(strSelect, myConnection); dtrReader=myCommand.ExecuteReader();
The problem is I need to check to see if any data has been returned from the SQL query, if there are no rows/ data returned by the query then I need to display a message to say that there aren't. I know that there isn't a 'number of rows method' for the dtrReader, so does anybody know how I could do this?
I'm trying to store multiple selected checkboxes from a single checkboxlist, but i don't know where to start. Imagine i have three tables: tbl_events, tbl_organisors and tbl_settings and i want to store the organisors of an event. Each event can have multiple organisors, so each organisor should be added as a single row into tbl_settings. I know how to bind tbl_organisors to a checkboxlist, but how do i store the results (meaning: add the rows to tbl_settings) ?
tbl_events: Event_ID (PK) and Event_Name tbl_organisors: User_ID and user_name. tbl_settings: Settings_ID (PK), Event_ID and User_ID
Checkboxlist:
[Code]....
SQLDatasource:
[Code]....
Initially all checkboxes will be unchecked, but users must be able to select multiple organisors from the checkboxlist and then store them into the DB by submitting a form. So the query will look something like: INSERT INTO tbl_settings (user_id, event_id) VALUES (@user_id, @event_id). And this is where my head cracks
1) How do i loop through all selected checkboxes and store each value (user_id) in a new row in tbl_settings? 2) After saving, the users reloads the page and the organisors he just selected must be selected by default in the checkboxlist. How?
The short story is, I'm developing an SSIS package to select from a remote Oracle database (read: no Windows Authentication) and store into an SQL Server db. I can execute the package just fine in development and after importing, but when I run it as a scheduled job, I get an ora-01017 error (bad un/pw). The details are, I built this package and tested in in BIDS but came across the problem that BIDS really doesn't save the password I'd set for the Oracle connection. After poking around a bit, I found this
[URL] which showed how to create an XML configuration which the package could then read. Fiddled around with that, got it working in BIDS. Connected to Integration Services on the server on which I want to run the package, imported it, right-clicked and did the "Run Package" option as a test, it works great. However, when I connect to the same server's Database Engine to create and schedule a job, I cannot connect to Oracle. For some reason, it seems as if the package is not reading the configuration when run in schedule.
I've tried removing the job and re-working it, thinking maybe it didn't pick up the new version when I re-imported the package. A new job had the same problem. Next, I tried re-naming the .dtsConfig and doing the "Run Package" option as a test. Failed with the same error. A bit surprised, I thought I'd get some kind of file error and we wouldn't get as far as trying to talk to Oracle. Anyway, thinking maybe it's permissions on the configuration, fixed the .dtsConfig name and gave full access to Everyone. That ought to let the Agent see it. Scheduled up the job, still can't talk to Oracle. So it seems as if the scheduled version is ignoring the configuration. Anyone have any idea what I'm missing, that scheduling an SSIS package makes it act differently than running it manually? BTW, the instance under which we're running the package is VS 2005. BIDS 2005 to build the package.
iam Working on Asp.net Web apliation using c#.net, in system folder (Ex: E://Santhu) i have few Flat files and Excels Files .So My Application should read those files automatically and should store the data into my database..
I'm Using a DataReader to Read about 100,000 records, my code look like :
[Code]....
I have a per row computation in reading the rows on GetMyType2Info() method, and this method also another method that I return only one record by ExecuteReader(). the problem is that when the MyTypeList (List<T>) has about 21,000 Items of MyType (<T>) System.OutOfMemoryException is thrown. wanted to know how to resolve this and wanted to know more about the maximum size of List<T> capacity. in addition the execution of the main Query with 100,000 records take about 4 seconds in SQLServer a record has only types of nvarchar , float,datetime and int
I have a record created date stored as" 2010-05-16 15:44:18.700" in sql server database. When I read this date it gets converted to "5/16/2010 3:44:18 PM" . How should I read it so that I don't loose the ending '700' value so that it gets written exactly to another database.Code for reading the record:
String myConn = ConfigurationManager.ConnectionStrings["DBConnectionString"].ToString(); SqlConnection con = new SqlConnection(myConn); SqlCommand cmd = new SqlCommand();[code].....
I have couple of DDL's which let user choose couple of different values from it. Once the user has made his selection he clicks on the "Submit" buttion which redirects the user to the other page, which then displays table from backend SQL DB. The pages are named Page1.aspx and Page2.aspx resp. I am using Querystring to carry forward the values of the DDL's to Page2.aspx.
How can i modify the query in such a way that even if one of the DDL's is left blank the Query would ignore that and shall produce the table considering value of DDL2 in the where clause. In case both the DDL's are empty then the query will not have a where clause and shall showcase the complete table as such. I've written a query for this but it's not working the way it shoul.Here is my code for the SQLDataSource: [Code]....
I'm trying to implement a recipe search page that allows users to specify search criteria by selecting checkboxes that match desired recipe attributes. All the data is stored in a database uing tables with 1 - many relationships. Each recipe can have multiple attributes from any of 5 attribute tables. I want to find all the recipes that match the user-selected criteria and display them in a grid. For example, the user may want a breakfast (attribute 1) recipe that is made with fruit and milk (attributes 2 and 3), is low-fat and high fiber (attributes 4 and 5), and takes less than 15 minutes to prepare (attribute 6). The query for this example might look something like:
FROM recipes, recipeMeals, recipeDishes, recipeFoodGrps, recipeNutrients, recipeFixTimes
WHERE recipes.id = recipeMeals.recipeId and recipes.id = recipeDishes.recipeId and recipes.id = recipeFoodGrps.recipeId and recipes.id = recipeNutrients.recipeId and recipes.id = recipeFixTimes.recipeId and recipeMeals.mealId in (1) and recipeDishes.dishId in (5) and recipeFoodGrps.fdGrpId in (1, 6) and recipeNutrients.nutrAttsId in (2, 3) and recipeFixTimes.fixTimeId in (1)
I' can generate the SQL but can't figure out how to bind it to a grid control. No could I see how to get any of the data controls to build the query for me. Is there a way to say "execute this query and display the results in a GridView"?
