This might sound strange but exactly this is what I want to do:
I have a TestMehod Currency_ReadItem_Test() which tests ReadItem() method in Currency class. This ReadItem() takes IDataReader object as an parameter and fills local data members in the class.
Now the problem is I want to test this ReadItem() in my TestMethod which has a Excel Sheet DataSource.
Any idea how can I first fill my Reader from Excel sheet so that it can be passed to this function in oder to test it?
Any help would be appreciated.
Thanks
One way is to read the spreadsheet via ADO.NET - then you just use ExecuteReader for some query you define.
Alternatively, you could use the Excel API and load the data you want into a DataTable, and then use a DataTableReader. Or if you don't like DataTable and you know for sure the schema of the data (i.e. fixed and rigid) you could also populate a List<SomeType> and use ObjectReader from "FastMember" (open source)
Related
I am trying to convert the data I already have in a Worksheet in to a DataTable using ClosedXML but I cannot find an overload method for what I need.
This is the code that I am trying:
NewWorksheet.Cell(1, 1).InsertTable();
The closest overload method is the single with an IEnumerable or DataTable but what would I put in there? There is no overload method that takes a range.
Here is the documentation page but nothing meets my need.
InsertTable inserts an existing DataTable into the spreadsheet. You want to do the reverse. That's not possible in ClosedXML.
The question:
Do you guys know if there is any way that I can put an object in the header of a DataTable column, instead of an integer or a string?
Further explanation:
I'm writing a library that, in some moment, will read data from different meteorological stations. The data I'll read will be, for example, temperature, wind speed, atmospheric pressure, etc. These values can be read in different units (km/h, mph, celsius, fahrenheit) and the information about these units will be in a separate source, not together with the data itself. I'll be reading a XML file that will contain all the information about this datafile and, what I wanted to do is create an object with different attributes and use this object as the header of each column of the DataTable. A bit complicated explanation but I think that I was clear enough.
Do you think that it is possible using native .NET types or, if I wanted to do exactly this way I'd have to create my own table class?
Thank you all!
There is a DataColumn.ExtendedProperties collection, which works like a dictionary and can hold any objects.
So every DataTable column can have an object associated with it, which have description of type, units and any other info.
I have a SP I want to execute and save the groos result aside (in a class field).
Later on I want to acquire the values of some columns for some rows from this result.
What returned types are possible? Which one is the most sutiable for my goal?
I know there are DataSet, DataReader, resultSet. what else?
What is the main difference between them ?
If you want to store the results and use them later (as you have written), you may use the heavy data sets or fill the lightweight lists with custom container types via the data reader.
Or in case you want to consume the results immediately, go on with the data reader.
Result set is the old VB6 class AFAIK or the current Java interface.
The traditional way to get data is by using the the classes in System.Data.SqlClient namespace. You can use the DataReader which is a read only forward type of cursor, fast and efficient when you just want to read a recordset. DataReader is bindable but you read it one record at the time and therefore don't have the options of going back, for instance. If the recordset is very big the reader is also good because it stores just one record at the time in memory.
You can use the DataAdapter and get a DataSet and then you have a complete control of all the data within the DataSet-class. It is heavier on the system but very powerful when you need to work with the data in you application. You can also use DataSet if the query returns more than one recordset.
So it really depends on what you need to do with the data after getting it from the database. If you just need to read it into something else, use DataReader otherwise DataSet.
I have been asked to create import functionality in my application. I am getting an excel worksheet as input. The worksheet has column headers followed by data. The users want to simply select an xls file from their system, click upload and the tool deletes the table in the database and adds this new data.
I thought the best way would be too bring the data into a datatable object and do a foeach for every row in the datatable insert row by row into the db.
My question is what can anyone give me code to open an excel file, know what line the data starts on in the file, and import the data into a datable object?
Take a look at Koogra.
You instantiate a WorkBook object from a path to an XLS file.
You access a WorkSheet object from the workbook's Sheets property.
You can enumerate over the rows in the worksheet by accessing the sheet's Rows property from index MinRow to MaxRow.
You can enumerate over the cells in a given row by accessing the row's Cells property from index MinColumn to MaxColumn.
Each cell has a Value property (object) as well as a FormattedValue method (string).
Give it a try -- I've found it to be extremely intuitive and easy to use.
You can make use of an OleDbConnection to connect to excel file and the query it using SQL queries.
If it is an Asp.Net application, then you make use of the FileUpload control and get the bytes from the file. Then you will have to manually convert it to a datatable.
Try out these links:
OleDbConnection to excel file
Byte array to datatable
What your looking for is the concept described Here
Providing you dont want to use a third party library anyway, else Dans solution will suit you
First you have to download the dll file namely
NExcel.dll
By using this dll you can make various object which are very useful for
import excel data in .net using both vb as well as c#.
Good luck.
We are communicating with a 3rd party service using via an XML file based on standards that this 3rd party developed. They give us an XML template for each "transaction" and we read it into a DataSet using System.Data.DataSet.ReadXML, set the proper values in the DataSet, and then write the XML back using System.Data.DataSet.WriteXML. This process has worked for several different files. However, I am now adding an additional file which requires that an integer data type be set on one of the fields. Here is a scaled down version:
<EngineDocList>
<DocVersion>1.0</DocVersion>
<EngineDoc>
<MyData>
<FieldA></FieldA>
<FieldB></FieldB>
<ClientID DataType="S32"></ClientID>
</MyData>
</EngineDoc>
</EngineDocList>
When I look at the DataSet created by my call to ReadXML to this file, the MyData table has columns of FieldA, FieldB, and MyData_ID. If I then set the value of MyData_ID and then make the call to WriteXML, the export XML has no value for ClientID. Once again, if I take a way the DataType, then I do have a ClientID column, I can set it properly, and the exported XML has the proper value. However, the third party requires that this data type be defined.
Any thoughts on why the ReadXML would be renaming this tag or how I could otherwise get this process to work? Alternatively, I could revamp the way we are reading and writing the XML, but would obviously rather not go down this path although these suggestions would also be welcome. Thanks.
I would not do this with a DataSet. It has a specific focus on simulating a relational model. Much XML will not follow that model. When the DataSet sees things that don't match it's idea of the world, it either ignores them or changes them. In neither case is it a good thing.
I'd use an XmlDocument for this.