How to load column data from DataReader? - c#

I'm porting application to ASP.Net 5.0 with EF7 and found several problems. One of the issues is MS have dropped DataTable. I'm trying to transfer a bit of code to not use DataTable but read from SQLDataReader and record this into entities I have. I have to read data by columns, but looks like datareader can read only once.
The old code:
Series[] arrSeries = new Series[dt.Columns.Count - 1];
IList<Categories> arrCats = new List<Categories>();
Categories arrCat = new Categories();
foreach (DataColumn dc in dt.Columns)
{
var strarr = dt.Rows.Cast<DataRow>().Select(row => row[dc.Ordinal]).ToList();
if (dc.Ordinal == 0)
{
arrCat.category = strarr.Select(o => new Category { label = o.ToString() }).ToList();
}
else
{
Series s = new Series()
{
seriesname = dc.ColumnName,
renderas = null,
showvalues = false,
data = strarr.Select(o => new SeriesValue { value = o.ToString() }).ToList()
};
arrSeries[dc.Ordinal - 1] = s;
}
}
arrCats.Add(arrCat);
MultiFusionChart fusChart = new MultiFusionChart
{
chart = dictAtts,
categories = arrCats,
dataset = arrSeries
};
return fusChart;
The new code:
Series[] arrSeries = new Series[colColl.Count - 1];
IList<Categories> arrCats = new List<Categories>();
Categories arrCat = new Categories();
arrCat.category = new List<Category>();
for (int i = 0; i < reader.FieldCount; i++)
{
Series s = new Series()
{
seriesname = reader.GetName(i),
renderas = null,
showvalues = false
};
while (reader.Read())
{
if (i == 0)
{
Category cat = new Category();
cat.label = reader.GetValue(i).ToString();
arrCat.category.Add(cat);
}
else
{
SeriesValue sv = new SeriesValue();
sv.value = reader.GetValue(i).ToString();
s.data.Add(sv);
arrSeries[i - 1] = s;
}
}
}
arrCats.Add(arrCat);
MultiFusionChart fusChart = new MultiFusionChart
{
chart = dictAtts,
categories = arrCats,
dataset = arrSeries
};
return fusChart;
Where the code works, it returns null for Series. And I believe this is because reader went to the end while recording Categories. As far as I know it is not possible to reset DataReader?
Is there a way to load column data from DataReader to List? Or maybe there is other way how I can replace DataTable in this example?

You can read value from multiple columns by specifying its index like this
int totalColumns = reader.FieldCount;
for(int i=0;i<totalColumns;i++)
{
var label = reader.GetValue(i);
}
You can select value of all columns by looping through columns.
GetValue takes int as argument which is index of column not the index of row.

The problem is in your for loop. At first when your i is 0, You have initialized a 'Series` object S. After that,
while (reader.Read())
will read your entire Reader while your i will still be zero. SO only the
if(i == 0)
condition will return true and your entire reader will be spent. Afterwards, for i >= 1,
while (reader.Read())
will always return false keeping your array, arrSeries blank. Remove the while loop and directly read value from the dataReader using the index,
reader.GetValue(i);

Related

I need helping adding two different rows(with same columns) to the same datatable

Working on a windows form application that reads in data from csv files and adds the data to a Datagridview. I ran into an issue with all of the rows being added to the datable and being displayed on the datagridview. The datagridview displays the datarows from the first two if conditions and OneRow if condition only. It will not add the rows from the twoRow if condition if the datable and datagridview rows are populated with the OneRow if condition rows. But i want the rows from both OneRow and TwoRow to be displyed. Also the rows from TwoRow do populate the datatable and datagridview when I comment(/**/) out the OneRow if condition. But I need both to populate the table. Thanks in advance!
Construct.MainDataTable.Columns.Add("Date", typeof(DateTime));
Construct.MainDataTable.Columns.Add("Time");
Construct.MainDataTable.Columns.Add("Serial");
Construct.MainDataTable.Columns.Add("Type");
Construct.MainDataTable.Columns.Add("level");
Construct.MainDataTable.Columns.Add("price");
Construct.MainDataTable.Columns.Add(" Limit");
Construct.MainDataTable.Columns.Add("last Limit");
Construct.MainDataTable.Columns.Add("Data");
..........................
...............................................
DataRow oneRow = Construct.MainDataTable.NewRow();
DataRow twoRow = Construct.MainDataTable.NewRow();
dataGridView2.AllowUserToAddRows = false;
if (line.Split(',')[2].Equals("Time"))
{
time = line.Split(',')[3];
date = line.Split(',')[1];
}
if (line.Split(',')[2].Equals("Level"))
{
level = line.Split(',')[3];
}
//OneROw(IF condition)
if ((Convert.ToDecimal(line.Split(',')[8])) < (Convert.ToDecimal (line.Split(',')[12])))
{
type = line.Split(',')[1];
serial = line.Split(',')[7];
price = line.Split(',')[3];
Limit = line.Split(',')[8];
lastLimit = line.Split(',')[10];
Data = line.Split(',')[12];
oneRow["Date"] = date;
oneRow["Time"] = time;
oneRow["Serial"] = serial;
oneRow["Type"] = type;
oneRow["level"] = level;
oneRow["price"] = price;
oneRow[" Limit"] = Limit;
oneRow["last Limit"] = lastlimit;
oneRow["Data"] = Data;
Construct.MainDataTable.Rows.Add(oneRow);
}
//TwoROw(IF condition)
if ((line.Contains('"')) && ((line.Contains("NG"))))
{
price = line.Split(',')[3];
type = line.Split(',')[1];
serial = line.Split(',')[7];
Limit = line.Split('"')[7];
var valLimit = Limit.Split(',').Select(a => Convert.ToInt32(a, 16));
var limitJoin = String.Join(",", valLimit);
lastlimit = line.Split('"')[1];
var vallastLimit = lastlimit.Split(',').Select(d => Convert.ToInt32(d, 16));
var lastJoin = String.Join(",", vallastLimit);
Data = line.Split('"')[5];
var valDatas = Data.Split(',').Select(s => Convert.ToInt32(s, 16));
var dataJoin = String.Join(",", valDatas);
twoRow["Date"] = date;
twoRow["Time"] = time;
twoRow["Serial"] = serial;
twoRow["Type"] = type;
twoRow["level"] = level;
twoRow["price"] = price;
twoRow["Limit"] = limitJoin;
twoRow["last Limit"] = lastJoin;
twoRow["Data"] = dataJoin;
Construct.MainDataTable.Rows.Add(twoRow);
}
dataGridView2.DataSource = Construct.MainDataTable;
Can't add a comment because I don't have enough karma so I ask my questions here: So, if I understood your problem you can't add data from one .csv file if it have more then one row? Why are you using 2 different if conditions for row in .csv file?
If you have empty data in row never mind you can still place them to your DataTable column, so you can use loop to add data from .csv to your DataTable. Try some thing like this:
public static DataTable CsvToDataTable(string csv)
{
DataTable dt = new DataTable();
string[] lines = csv.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.RemoveEmptyEntries);
Regex onlyDeimiterComma = new Regex(",(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))");
for (int i = 0; i < lines.Length; i++)
{
DataRow row = dt.NewRow();
string[] cells = onlyDeimiterComma.Split(lines[i]);
for (int j = 0; j < cells.Length; j++)
{
if (i == 0)
{
if (j == 0)
{
dt.Columns.Add(cells[j], typeof(DateTime));
}
else
{
dt.Columns.Add(cells[j]);
}
}
else
{
row[j] = cells[j];
}
}
dt.Rows.Add(row);
}
return dt;
}
Just call this method anywhere in your code and give it string read from your .csv file.
You can try to compile this code here and see how it works on .csv data with different data (empty columns, quoted text, quoted commas)
UPD: If you need to fill DataTable from two different .csv files you can still use code above. Just call it twice for both files and then Merge two DataTable, like this:
DataTable dt = CsvToDataTable(csvFileOne);
DataTable dtTwo = CsvToDataTable(csvFileTwo);
dt.Merge(dtTwo);

Get Names of all Columns in Excel sheet in SpreadSheetLight

I'm trying to populate a combobox with the names of the columns in a spreadsheet.
I'm using the spreadsheetlight library. I can set the cell value using the following code where A refers to column name and 1 refers to row name. (Am I right?)
But how can I get the the name of all columns in all sheets?
SLDocument sl = new SLDocument();
sl.SetCellValue("A1", true);
First, get the last column index using SLWorksheetStatistics:
SLWorksheetStatistics stats = sl.GetWorksheetStatistics();
int endColumnIndex = stats.EndColumnIndex;
Then iterate through the columns:
var headers = new List<string>();
for (int i = 1; i <= endColumnIndex; i++){
headers.Add(sl.GetCellValueAsString(1, i));
}
The following will print the values "foo" and "bar" from the column list:
var fileName = "test.xlsx";
var sl = new SLDocument(fileName);
foreach (var sheetName in sl.GetWorksheetNames())
{
SLDocument sheet = new SLDocument(fileName, sheetName);
sheet.SetCellValue("A1", "foo");
sheet.SetCellValue("B1", "bar");
SLWorksheetStatistics stats = sheet.GetWorksheetStatistics();
int endColumnIndex = stats.EndColumnIndex;
var headers = new List<string>();
for (int i = 1; i <= endColumnIndex; i++)
{
headers.Add(sheet.GetCellValueAsString(1, i));
}
foreach (var column in headers)
{
Console.WriteLine(column);
}
Console.ReadKey();
}

Google BigQuery REST API C# copy/export table with nested schema as CSV

Is there a way to export a whole table with a nested schema from Google BigQuery using the REST API as a CSV?
There is an example for doing this (https://cloud.google.com/bigquery/docs/exporting-data) with a not nested schema. This works fine on the not nested columns in my table. Here is the code of this part:
PagedEnumerable<TableDataList, BigQueryRow> result2 = client.ListRows(datasetId, result.Reference.TableId);
StringBuilder sb = new StringBuilder();
foreach (var row in result2)
{
sb.Append($"{row["visitorId"]}, {row["visitNumber"]}, {row["totals.hits"]}{Environment.NewLine}");
}
using (var stream = new MemoryStream(Encoding.UTF8.GetBytes(sb.ToString())))
{
var obj = gcsClient.UploadObject(bucketName, fileName, contentType, stream);
}
In BQ there are columns like totals.hits, totals.visits...If I try to address them I got the errormessage that there is not such a column. If I am addressing "totals" I get the objectname "System.Collections.Generic.Dictionary`2[System.String,System.Object]" in the rows in my csv.
Is there any possibility to do something like that? In the end I want my table from GA in BQ as a CSV somewhere else.
It is possible. Select every column you need like in the following shema und flatten everything was need to be flattened.
string query = $#"
#legacySQL
SELECT
visitorId,
visitNumber,
visitId,
visitStartTime,
date,
hits.hitNumber as hitNumber,
hits.product.productSKU as product.productSKU
FROM
FLATTEN(FLATTEN({tableName},hits),hits.product)";
//Creating a job for the query and activating legacy sql
BigQueryJob job = client.CreateQueryJob(query,
new CreateQueryJobOptions { UseLegacySql = true });
BigQueryResults queryResult = client.GetQueryResults(job.Reference.JobId,
new GetQueryResultsOptions());
StringBuilder sb = new StringBuilder();
//Getting the headers from the GA table and write them into the first row of the new table
int count = 0;
for (int i = 0; i <= queryResult.Schema.Fields.Count() - 1; i++)
{
string columenname = "";
var header = queryResult.Schema.Fields[0].Name;
if (i + 1 >= queryResult.Schema.Fields.Count)
columenname = queryResult.Schema.Fields[i].Name;
else
columenname = queryResult.Schema.Fields[i].Name + ",";
sb.Append(columenname);
}
//Getting the data from the GA table and write them row by row into the new table
sb.Append(Environment.NewLine);
foreach (var row in queryResult.GetRows())
{
count++;
if (count % 1000 == 0)
Console.WriteLine($"item {count} finished");
int blub = queryResult.Schema.Fields.Count;
for (Int64 j = 0; j < Convert.ToInt64(blub); j++)
{
try
{
if (row.RawRow.F[Convert.ToInt32(j)] != null)
sb.Append(row.RawRow.F[Convert.ToInt32(j)].V + ",");
}
catch (Exception)
{
}
}
sb.Append(Environment.NewLine);
}

Copying the value of one data Table to another data Table in Mvc

Actually, i have two data tables. Here is the code for reference. Actually Relationship holds the sub string values(Code not mentioned here). So i am splitting the data's to store in two table's based on the condition.
if (child.Relationship.Contains("P"))
{
var newRow = dataTable.NewRow();
newRow["EmployeeNo"] = child.EmployeeNo;
newRow["FirstName"] = child.FirstName;
newRow["MiddleName"] = child.MiddleName;
newRow["LastName"] = child.LastName;
newRow["FullName"] = child.FullName;
newRow["MemberIc"] = child.MemberIc;
dataTable.Rows.Add(newRow);
}
else
{
var newRow1 = dataTable1.NewRow();
newRow1["EmployeeNo"] = child.EmployeeNo;
newRow1["FirstName"] = child.FirstName;
newRow1["MiddleName"] = child.MiddleName;
newRow1["LastName"] = child.LastName;
newRow1["FullName"] = child.FullName;
newRow1["MemberIC"] = child.MemberIC;
dataTable1.Rows.Add(newRow1);
}
So, whenever the MemberIc in the second data table is empty. I need to copy the MemberIc from first data table(only if EmployeeNo Matches) based on the EmployeeNo.
How can i copy the value ? Any help appreciated. Thanks in advance !!!
Here you go.
var rows = datatable.Select("EmployeeNo = " + child.EmployeeNo);
var memberIC = 0;
if(rows.length > 0)
{
memberIC = rows[0].Field<int>("memberIC");
}
if (child.Relationship.Contains("P"))
{
var newRow = dataTable.NewRow();
newRow["EmployeeNo"] = child.EmployeeNo;
newRow["FirstName"] = child.FirstName;
newRow["MiddleName"] = child.MiddleName;
newRow["LastName"] = child.LastName;
newRow["FullName"] = child.FullName;
newRow["MemberIc"] = child.MemberIc;
dataTable.Rows.Add(newRow);
}
else
{
var newRow1 = dataTable1.NewRow();
newRow1["EmployeeNo"] = child.EmployeeNo;
newRow1["FirstName"] = child.FirstName;
newRow1["MiddleName"] = child.MiddleName;
newRow1["LastName"] = child.LastName;
newRow1["FullName"] = child.FullName;
newRow1["MemberIC"] = child.MemberIC == 0 ? memberIC : child.MemberIC;
dataTable1.Rows.Add(newRow1);
}
This has nothing to do with C#, ADO.NET or datatable. This is a simple logic of what to check and where to check.

Script to parse CSV values

I'm using this code to parse the values and store them in List. The first row has names which are getting stored fine. But when storing values, only the second row is bring saved. I'm not sure what edit I need to make so that it parses all other rows as well.
Please see image and code below.
List<string> names = new List<string>(); // List to store Key names
List<string> values = new List<string>(); // List to store key values
using (StreamReader stream = new StreamReader(filePath))
{
names = stream.ReadLine().Split(',').ToList(); // Seperate key names and store them in a List
values = stream.ReadLine().Split(',').ToList(); // Seperate key values and store them in a list
}
See if something like this works better:
// List to store Key names
List<string> names = new List<string>();
// List to store key values
List<List<string>> values = new List<string>();
using (StreamReader stream = new StreamReader(filePath))
{
if(!stream.EndOfStream)
{
// Seperate key names and store them in a List
names = stream.ReadLine().Split(',').ToList();
}
while(!stream.EndOfStream)
{
// Seperate key values and store them in a list
values.Add(stream.ReadLine().Split(',').ToList());
}
}
This changes your values list to be a list of a list of strings so that each row will a list of string
While this probably isn't the best way to parse a .csv, if your data is consistent and the file format is strongly consistent you can probably get away with doing it like this. As soon as you try this with odd values, quoted strings, strings with commas, etc., you'll need a different approach.
i have written the code for grid view make changes it to a list.I think it will help
protected void Button1_Click(object sender, EventArgs e)
{
if (FileUpload1.HasFile)
{
string s = FileUpload1.FileName.Trim();
if (s.EndsWith(".csv"))
{
FileUpload1.PostedFile.SaveAs(Server.MapPath("~/data/" + s));
string[] readText = File.ReadAllLines(Server.MapPath("~/data/" + s));
DataSet ds = new DataSet();
DataTable dt = new DataTable();
// Array.Sort(readText);
for (int i = 0; i < readText.Length; i++)
{
if (i == 0)
{
string str = readText[0];
string[] header = str.Split(',');
dt.TableName = "sal";
foreach (string k in header)
{
dt.Columns.Add(k);
}
}
else
{
DataRow dr = dt.NewRow();
string str1 = readText[i];
if (readText[i] == ",,,,")
{
break;
}
string[] rows = str1.Split(',');
if (dt.Columns.Count == rows.Length)
{
for (int z = 0; z < rows.Length; z++)
{
if (rows[z] == "")
{
rows[z] = null;
}
dr[z] = rows[z];
}
dt.Rows.Add(dr);
}
else
{
Label1.Text = "please select valid format";
}
}
}
//Iterate through the columns of the datatable to set the data bound field dynamically.
ds.Merge(dt);
Session["tasktable"] = dt;
foreach (DataColumn col in dt.Columns)
{
BoundField bf = new BoundField();
bf.DataField = col.ToString();
bf.HeaderText = col.ColumnName;
if (col.ToString() == "Task")
{
bf.SortExpression = col.ToString();
}
GridView1.Columns.Add(bf);
}
GridView1.DataSource = ds;
GridView1.DataBind();
}
else
{
Label1.Text = "please select a only csv format";
}
}
else
{
Label1.Text = "please select a file";
}
}

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