All
I have a dataset with 11 Columns and 5 rows which I need to form into a json string.
The DataSet is created thus:-
For liCounter = 1 To liTotalCounter
If IsDBNull(dt.Rows(liCounter).Item(0)) = False Then
Dim dr As DataRow = PlayerTable.NewRow()
dr("id") = CType(dt.Rows(liCounter).Item(0), Integer)
dr("teamid") = CType(dt.Rows(liCounter).Item(1), Integer)
dr("Team_Name") = CType(dt.Rows(liCounter).Item(2), String)
dr("pno") = CType(dt.Rows(liCounter).Item(3), String)
dr("Player_Name") = CType(dt.Rows(liCounter).Item(4), String)
dr("Goals") = CType(dt.Rows(liCounter).Item(6), Integer)
dr("Games") = CType(dt.Rows(liCounter).Item(5), Integer)
dr("Assists") = CType(dt.Rows(liCounter).Item(7), Integer)
dr("Points") = CType(dt.Rows(liCounter).Item(8), Integer)
dr("Pens") = CType(dt.Rows(liCounter).Item(9), Integer)
dr("Misc") = CType(dt.Rows(liCounter).Item(10), Integer)
PlayerTable.Rows.Add(dr)
End If
Next
ds.AcceptChanges()
JsonString = JsonConvert.SerializeObject(dt)
Now an example of the returned Json String is :-
"[{""id"":3,""teamid"":1,""name"":""Team 1"",""pno"":3,""name1"":""Player 1 "",""games"":2,""goals"":3,""assists"":4,""points"":5,""penalties"":8,""misc"":7},{""id"":4,""teamid"":1,""name"":""Bandit"",""pno"":7,""name1"":""Player 2"",""games"":0,""goals"":0,""assists"":0,""points"":0,""penalties"":0,""misc"":0},{""id"":5,""teamid"":1,""name"":""Bandit"",""pno"":8,""name1"":""Player 3"",""games"":0,""goals"":0,""assists"":0,""points"":0,""penalties"":0,""misc"":0},{""id"":6,""teamid"":1,""name"":""Bandit"",""pno"":9,""name1"":""Player 4 "",""games"":0,""goals"":0,""assists"":0,""points"":0,""penalties"":0,""misc"":0},{""id"":7,""teamid"":1,""name"":""Bandit"",""pno"":11,""name1"":""Player 5 "",""games"":0,""goals"":0,""assists"":0,""points"":0,""penalties"":0,""misc"":0}]"
When I go to check that the json string is valid using json checker, the error indicates that there is a problem with the string e.g.
Parse error on line 1:
"[{""id"":3,""teamid"":1
Expecting 'EOF', '}', ':', ',', ']', got 'STRING'
I have tried other forms of serializing a dataset or datatable, but the same error is produced, so I have to be doing something wrong somewhere...
Any Advice would be appreciated.
-Colin
Related
I'm reading a JSON file from an external partner which is not totally consistent (and they are not changing it anytime soon).
I want to check the value of the field bathroom and store that in an integer. So here's a mapping of the potential values there are and what I would like to get:
"" = 0
= 0 (here no value is present)
2 = 2
"2" = 2
But whatever I try (see below) I get the error:
Input string was not in a correct format.
Dim json as string = "[{""bathrooms"": """"}, {""bathrooms"": }, {""bathrooms"": 2},{""bathrooms"": ""1""}]"
Dim iBathrooms As Integer
Dim jsonArray As Newtonsoft.Json.Linq.JArray = JArray.Parse(json)
For Each item In jsonArray
iBathrooms= If(item.Value(Of Integer?)("bathrooms"), 0)
iBathrooms = If(CType(item("bathrooms"), Integer?), 0)
Int32.TryParse(item("bathrooms").Value(Of Integer).ToString, iBathrooms)
Next
I already checked here: Get value from JToken that may not exist (best practices)
If the problem with the JSON is consistently that it is missing the value, you could insert, say, an empty string:
Dim json As String = "[{""bathrooms"": """"}, {""bathrooms"": }, {""bathrooms"": 2},{""bathrooms"": ""1""}]"
Dim re = New Text.RegularExpressions.Regex(":\s*}")
Dim json2 = re.Replace(json, ": """"}")
Console.WriteLine(json2)
Outputs:
[{"bathrooms": ""}, {"bathrooms": ""}, {"bathrooms": 2},{"bathrooms": "1"}]
which is valid JSON.
Then you could check if the value can be parsed as an integer:
Dim json As String = "[{""bathrooms"": """"}, {""bathrooms"": """"}, {""bathrooms"": 2},{""bathrooms"": ""1""}]"
Dim re = New Text.RegularExpressions.Regex(":\s*}")
json = re.Replace(json, ": """"}")
Dim nBathrooms As Integer
Dim jsonArray As Newtonsoft.Json.Linq.JArray = JArray.Parse(json)
For Each item In jsonArray
Dim q = item("bathrooms")
If q IsNot Nothing AndAlso Integer.TryParse(q.Value(Of Object).ToString(), nBathrooms) Then
Console.WriteLine(nBathrooms)
Else
Console.WriteLine("Not specified.")
End If
Next
Right now, I'm developing web application using DevExpress BootstrapChart (v17.2.13.0) and I have binded the control with object datasource. Here is the example data used to be displayed in the graph:
Here is my objectives:
The graph will show the values of "ademand_im" and "rdemand_im" in different panes (I named them pane "A" and "B")
Each pane has "data_time" (date and time) as X-axis and the values ("ademand_im" or "rdemand_im") as Y-axis
Also, the values in each pane will be grouped by "hardware_id" so, in this case, there should be 2 line series of "83245551" and "88310991" in each pane (Note that "hardware_id" can be varied from time to time).
So the graph should look like this:
However, what I only acheive at this moment is that either the line series are shown in both panes but not grouped or not show anything in the graph.
Here is my code:
<dx:BootstrapChart ID="chart" ClientInstanceName="chart" runat="server"
DataSourceID="ods_ChartData" Height="640px" TitleText="Chart Data" CrosshairEnabled="true" Panes="A,B">
<ClientSideEvents Init="OnChartInit" />
<SettingsToolTip Shared="true" Enabled="true" OnClientCustomizeTooltip="ChartToolTip" />
<ArgumentAxis ArgumentType="System.DateTime" GridVisible="True" MinorGridVisible="True"
TickVisible="True" MinorTickVisible="True" TickInterval="1" MinorTickCount="3" TitleText="Date">
<Label DisplayMode="Rotate" RotationAngle="-0" Format-Formatter="FormatDate" />
</ArgumentAxis>
<ValueAxisCollection>
<dx:BootstrapChartValueAxis Pane="A" TitleText="ademand_im" />
<dx:BootstrapChartValueAxis Pane="B" TitleText="rdemand_im" />
</ValueAxisCollection>
<SettingsCommonSeries Type="Line" ArgumentField="data_time" Point-Size="0" />
<SettingsSeriesTemplate NameField="hardware_id" />
<SeriesCollection>
<dx:BootstrapChartLineSeries Pane="A" ValueField="ademand_im" />
<dx:BootstrapChartLineSeries Pane="B" ValueField="rdemand_im" />
</SeriesCollection>
</dx:BootstrapChart>
In this code, if I remove the "SettingsSeriesTemplate" line, the data will show in both panes but only in single line in each pane. However, if I keep this line the graph will not show anything.
After I tried to understand how this control works, the only solution I found is that I have to pivot "hardware_id" columns into "ademand_im" and "rdemand_im" values, which may be not the ideal one.
So instead of having "hardware_id", "ademand_im" and "rdemand_im" columns, the table should be transformed to have like "ademand_im_83245551", "ademand_im_88310991", "rdemand_im_83245551" and "rdemand_im_88310991" columns instead.
This is how the table after transforming looks like:
Here is the function codes that I used to transform the table (VB.NET):
<Extension()>
Public Function PivotDataTableColumnGroup(srcData As DataTable, rowGroupField As String, pivotColumnField As String, valueGroupFields As IEnumerable(Of String),
Optional ValueGroupColumnName As Func(Of String, String, String) = Nothing,
Optional otherFields As IEnumerable(Of String) = Nothing,
Optional GetOtherFieldValue As Func(Of DataTable, String, Object, Object) = Nothing
) As DataTable
Dim groupValueList As List(Of Object) = srcData.GetDistinctValuesByColumnName(rowGroupField)
Dim pivotValueList As List(Of Object) = srcData.GetDistinctValuesByColumnName(pivotColumnField)
Dim hasOtherFieldColumn As Boolean = Not (otherFields Is Nothing Or GetOtherFieldValue Is Nothing)
Dim dt As New DataTable
With dt
.Columns.Add(rowGroupField, srcData.Columns(rowGroupField).DataType)
For i As Integer = 0 To valueGroupFields.Count - 1
For j As Integer = 0 To pivotValueList.Count - 1
Dim columnName As String = GetColumnNameFromGroupFieldAndPivotValues(valueGroupFields(i), pivotValueList(j), ValueGroupColumnName)
dt.Columns.Add(columnName, srcData.Columns(valueGroupFields(i)).DataType)
Next
Next
If hasOtherFieldColumn Then
For i As Integer = 0 To otherFields.Count - 1
.Columns.Add(otherFields(i), srcData.Columns(otherFields(i)).DataType)
Next
End If
For i As Integer = 0 To groupValueList.Count - 1
Dim currentGroupValue As Object = groupValueList(i)
Dim dr As DataRow = dt.NewRow()
dr(rowGroupField) = currentGroupValue
If hasOtherFieldColumn Then
For j As Integer = 0 To otherFields.Count - 1
dr(otherFields(j)) = DBNullIfNothing(GetOtherFieldValue(srcData, otherFields(j), currentGroupValue))
Next
End If
For j As Integer = 0 To valueGroupFields.Count - 1
Dim currentField As String = valueGroupFields(j)
For k As Integer = 0 To pivotValueList.Count - 1
Dim currentPivotValue As Object = pivotValueList(k)
Dim columnName As String = GetColumnNameFromGroupFieldAndPivotValues(valueGroupFields(j), pivotValueList(k), ValueGroupColumnName)
Dim value As Object = (From row In srcData.AsEnumerable
Where row(rowGroupField) = currentGroupValue _
AndAlso row(pivotColumnField) = currentPivotValue
Select row(currentField)
).FirstOrDefault
dr(columnName) = DBNullIfNothing(value)
Next
Next
dt.Rows.Add(dr)
Next
End With
Return dt
End Function
<Extension()>
Public Function GetDistinctValuesByColumnName(dt As DataTable, columnName As String) As List(Of Object)
Dim valueList As List(Of Object) = (From row As DataRow In dt.AsEnumerable
Where Not IsDBNull(row(columnName))
Order By row(columnName)
Select row(columnName) Distinct
).ToList
Return valueList
End Function
Private Function GetColumnNameFromGroupFieldAndPivotValues(groupField As String, pivotValue As Object, Optional ValueGroupColumnName As Func(Of String, String, String) = Nothing) As String
Dim columnName As String = groupField & "_" & pivotValue.ToString()
If ValueGroupColumnName IsNot Nothing Then
columnName = ValueGroupColumnName(groupField, pivotValue)
End If
Return columnName
End Function
Public Function DBNullIfNothing(o As Object) As Object
If o Is Nothing Then Return DBNull.Value
Return o
End Function
And this is how I used the function to transform the table:
Dim chartData As DataTable = result.PivotDataTableColumnGroup("data_time", "hardware_id", {"ademand_im", "rdemand_im"}, Nothing, Nothing, Nothing)
ResultChartData = chartData 'Stored in ASPxHiddenField in JSON form
After that, instead of setting chart series properties in aspx file, I have to add chart series manually in code behind:
Private Sub chart_LoadProfile_DataBound(sender As Object, e As EventArgs) Handles chart_LoadProfile.DataBound
Using ResultChartData
Dim seriesList As List(Of String) = (From col As DataColumn In ResultChartData.Columns
Where col.ColumnName <> "data_time"
Order By col.ColumnName
Select col.ColumnName
).ToList
Dim hardWardCount As Integer = (From s In seriesList Where s.Contains("ademand_im_")).Count
Dim showInLegend As Boolean = hardWardCount > 1
With chart_LoadProfile.SeriesCollection
.Clear()
For i As Integer = 0 To seriesList.Count - 1
Dim fieldName As String = seriesList(i)
Dim hardwareId As String = seriesList(i).Split("_")(2)
Dim series As New BootstrapChartLineSeries
With series
.ArgumentField = "data_time"
.ValueField = fieldName
.Point.Size = 0
.ShowInLegend = showInLegend
If fieldName.Contains("ademand_im_") Then
.Pane = "A"
.Name = "kW - " & hardwareId
Else
.Pane = "B"
.Name = "kVar - " & hardwareId
End If
End With
.Add(series)
Next
End With
End Using
End Sub
I have a LINQ2Entity problem, I want to get the value, string, from a database, so I select FProducts.Serial_number, and to end the query, I do .ToDictionary.
The problem is, it tells me that it doesn't have sufficient parameters, to convert ToDictionary.
So I need something like select FProducts.Serial_number, Nothing). ToDictionary.
Also FProducts.Serial_number, 0).ToDictionary doesn't work.
Any recommendations?
Sub GetStatistics(ByVal ProductNumbers As List(Of String), ByRef Passed As Integer, ByRef FailedProducts As List(Of String))
Passed = 0
FailedProducts = Nothing
Dim tpDictionary As Dictionary(Of String, Integer)
For Each productNumber As String In ProductNumbers
Using context As New SelmaEntities
Dim Table = (From GoodProducts In context.TestResults
Where (GoodProducts.Art_no = productNumber)
Select GoodProducts.Art_no, GoodProducts.Failed)
tpDictionary = (From FProducts In context.TestResults
Where (FProducts.Art_no = productNumber And FProducts.Failed <> 0)
Order By FProducts.Serial_number
Select FProducts.Serial_number, ).ToDictionary
End Using
Next
End Sub
ToDictionary requires lambda expressions as parameters: one to select the dictionary key, one to select the value. So try:
tpDictionary = (From FProducts In context.TestResults
Where (FProducts.Art_no = productNumber And FProducts.Failed <> 0))
.ToDictionary(Function(p) FProducts.Serial_number, Function(p) 0)
var products = from p in FProducts select new { value=serial_number,key=productid};
Dictionary<string, int> dictionary = new Dictionary<string, int>();
foreach(var item in products){
dictionary.Add(item.value, item.key);
}
I have an 2-d arraylist with 2 fixed columns and dynamic rows. The arraylist will be assigned to the session variable at the end of the code below. My question is how can loop thorugh the arraylist from the session to get its value?
If .SQLDS.Tables(.sSQLDSTbl).Rows.Count > 0 Then
Dim NoOfAdjType(1, .SQLDS.Tables(.sSQLDSTbl).Rows.Count - 1)
For iRow As Integer = 0 To .SQLDS.Tables(.sSQLDSTbl).Rows.Count - 1
If Not .SQLDS.Tables(.sSQLDSTbl).Rows(iRow).Item("i_commAmt") Is System.DBNull.Value Then
NoOfAdjType(0, iRow) = .SQLDS.Tables(.sSQLDSTbl).Rows(iRow).Item("productType")
NoOfAdjType(1, iRow) = Format(.SQLDS.Tables(.sSQLDSTbl).Rows(iRow).Item("i_commAmt"), "#,##0.00")
End If
Next
Session("iNoOfAdjAmtType") = NoOfAdjType
End If
I have tried this but it's giving me error 'Too many arguments to 'Public Overridable Default Property Item(index As Integer) As Object'
Dim NoOfAdjType As ArrayList = CType(Session("iNoOfAdjAmtType"), ArrayList)
For i As Integer = 0 To NoOfAdjType.Count
Dim a As String = NoOfAdjType(0, i)
Dim b As String = NoOfAdjType(1, i)
Next
The type you are dealing with is Object(,). So when reading from the session you can cast it back to this type.
Here's an article on MSDN which illustrates how to read values from session:
Dim NoOfAdjType as Object(,) = CType(Session("iNoOfAdjAmtType"), Object(,))
' do something with the list
And if you wanted to perform the check safely ensuring that there is an item with the given id in the session:
If Session.Item("iNoOfAdjAmtType") IsNot Nothing Then
' We have a value in the session with the given id
Dim NoOfAdjType as Object(,) = CType(Session("iNoOfAdjAmtType"), Object(,))
End If
I am not certain what is the data-type of array, but this how you manipulate the multi-dimension arrays in VB.NET assuming data-type as object
' declaring variable of multi-dim array
Dim NoOfAdjType As Object(,)
' create array object of needed dimension (you may use redim keyword)
NoOfAdjType = new Object(1, .SQLDS.Tables(.sSQLDSTbl).Rows.Count - 1) {}
...
' push it in session
Session("iNoOfAdjAmtType") = NoOfAdjType
...
' get back from session
NoOfAdjType = DirectCast(Session("iNoOfAdjAmtType"), Object(,))
...
For i As Integer = 0 To NoOfAdjType.GetLength(0)
For j As Integer = 0 To NoOfAdjType.GetLength(1)
Dim a As Object = NoOfAdjType(i, j);
...
Next
Next
See this MSDN article for array in VB.NET: http://msdn.microsoft.com/en-us/library/wak0wfyt.aspx
Try this,
Dim a As String = NoOfAdjType(0)(0,0)
Or use
For Each arr As Object(,) In NoOfAdjType
Next
I have searched high and low to no avail, and this is last step before completing my project so please help! Thanks in advance!
The user will select an entry in a gridview, which then redirects them to a form that is populated with the data from the selected row (thus making the gridview editable in a more user friendly way). Null values are accepted by the DB and I would like to show null date values as blank (or " ") in the corresponding text boxes. Instead I get the error:
Conversion from type 'DBNull' to type 'Date' is not valid.
Here is my code:
'preceded by connection code
Dim sqlcmd As String = "SELECT * from Master WHERE RecNum = #recnum"
'Dim sqlCmd As New OleDb.OleDbCommand("SELECT * from Master WHERE RecNum = #recnum", connection)
Dim FileCommand3 As New OleDb.OleDbCommand(sqlcmd, connection)
FileCommand3.Parameters.AddWithValue("#recnum", user)
Dim Reader3 As OleDb.OleDbDataReader = FileCommand3.ExecuteReader()
If Reader3.Read Then
stock = myCStr(Reader3("StockNum"))
make = myCStr(Reader3("Make"))
color = myCStr(Reader3("Color"))
stockin = myCStr(Reader3("Stockin"))
ucistart = myCStr(Reader3("UCIStartDate"))
repairs = Reader3("Repairs")
tires = Reader3("tiresneeded")
onlot = Reader3("onlot")
sold = Reader3("sold")
year = myCStr(Reader3("year"))
model = myCStr(Reader3("model"))
location = Reader3("location")
srvcRO = myCStr(Reader3("svcROnum"))
ucicompldate = myCStr(Reader3("uciestcompletedate"))
collRO = myCStr(Reader3("collisionROnum"))
other = myCStr(Reader3("other"))
offprop = Reader3("offProperty")
detail = (Reader3("detail")
End If
connection.Close()
SoldCheckBX.Checked = sold
DetailTXTbox.Text = detail
'etc, etc
End Sub
I used the function mycstr to fix the dbnull to string error but it does not seem as simple to adapt to "date" data type
Function myCStr(ByVal test As Object) As String
If isdbnull(test) Then
Return ("")
Else
Return CStr(test)
End If
End Function
try this when you read the values from the reader with all your dates, this will first test to see if the date is dbnull, if it is then it will assign a nothing value and you should get your desired empty cell, otherwise it will show the date:
ucistart = IIf(reader3("UCIStartDate") Is DBNull.Value, Nothing, reader3("UCIStartDate"))
Have you tried using the Convert.IsDBNull function?
Here is the official documentation.