Develop Reference

Pull full dynamodb table with document model

string tableName = _awsSettings.TableSettings.Table + _awsSettings.TableSettings.Suffix;
Table table = Table.LoadTable(_amazonDynamoDb, tableName);
DocumentBatchGet batch = table.CreateBatchGet();
await batch.ExecuteAsync();
List<Document> results = batch.Results;
return results.As<Lab>();
The above code returns 0 results. I am hoping to return the entire table.
How can I, using the document model (Table.LoadTable), pull the entire table?

The Table.LoadTable() method returns a Table object, which is basically a wrapper for the DynamoDB client. This object does not contain any of the data that is in the actual table in AWS.
To read all of the items in a table, you need to use the Table.Scan() method. Here is some sample code that uses scan to dump the contents of a table to the standard output.
private static void DumpTable(Table table)
{
ScanFilter scanFilter = new ScanFilter();
Search search = productCatalogTable.Scan(scanFilter);
List<Document> documentList = new List<Document>();
do
{
documentList = search.GetNextSet();
foreach (var document in documentList)
PrintDocument(document);
} while (!search.IsDone);
}
private static void PrintDocument(Document document)
{
// count++;
Console.WriteLine();
foreach (var attribute in document.GetAttributeNames())
{
string stringValue = null;
var value = document[attribute];
if (value is Primitive)
stringValue = value.AsPrimitive().Value.ToString();
else if (value is PrimitiveList)
stringValue = string.Join(",", (from primitive
in value.AsPrimitiveList().Entries
select primitive.Value).ToArray());
Console.WriteLine("{0} - {1}", attribute, stringValue);
}
}

This C# code is to pull records from a dynamodb table having different guid's using BatchGet or CreateBatchGet
string tablename = "AnyTableName"; //table whose data you want to fetch
var BatchRead = ABCContext.Context.CreateBatchGet<ABCTable>(
new DynamoDBOperationConfig
{
OverrideTableName = tablename;
});
foreach(string Id in IdList) // in case you are taking string from input
{
Guid objGuid = Guid.Parse(Id); //parsing string to guid
BatchRead.AddKey(objGuid);
}
await BatchRead.ExecuteAsync();
var result = BatchRead.Results;
// ABCTable is the table modal which is used to create in dynamodb & data you want to fetch

C# Reading CSV to DataTable and Invoke Rows/Columns

i am currently working on a small Project and i got stuck with a Problem i currently can not manage to solve...
I have multiple ".CSV" Files i want to read, they all have the same Data just with different Values.
Header1;Value1;Info1
Header2;Value2;Info2
Header3;Value3;Info3
While reading the first File i Need to Create the Headers. The Problem is they are not splited in Columns but in rows (as you can see above Header1-Header3).
Then it Needs to read the Value 1 - Value 3 (they are listed in the 2nd Column) and on top of that i Need to create another Header -> Header4 with the data of "Info2" which is always placed in Column 3 and Row 2 (the other values of Column 3 i can ignore).
So the Outcome after the first File should look like this:
Header1;Header2;Header3;Header4;
Value1;Value2;Value3;Info2;
And after multiple files it sohuld be like this:
Header1;Header2;Header3;Header4;
Value1;Value2;Value3;Value4;
Value1b;Value2b;Value3b;Value4b;
Value1c;Value2c;Value3c;Value4c;
I tried it with OleDB but i get the Error "missing ISAM" which i cant mange to fix. The Code i Used is the following:
public DataTable ReadCsv(string fileName)
{
DataTable dt = new DataTable("Data");
/* using (OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\"" +
Path.GetDirectoryName(fileName) + "\";Extendet Properties ='text;HDR=yes;FMT=Delimited(,)';"))
*/
using (OleDbConnection cn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" +
Path.GetDirectoryName(fileName) + ";Extendet Properties ='text;HDR=yes;FMT=Delimited(,)';"))
{
using(OleDbCommand cmd = new OleDbCommand(string.Format("select *from [{0}]", new FileInfo(fileName).Name,cn)))
{
cn.Open();
using(OleDbDataAdapter adapter = new OleDbDataAdapter(cmd))
{
adapter.Fill(dt);
}
}
}
return dt;
}
Another attempt i did was using StreamReader. But the Headers are in the wrong place and i dont know how to Change this + do this for every file. the Code i tried is the following:
public static DataTable ReadCsvFilee(string path)
{
DataTable oDataTable = new DataTable();
var fileNames = Directory.GetFiles(path);
foreach (var fileName in fileNames)
{
//initialising a StreamReader type variable and will pass the file location
StreamReader oStreamReader = new StreamReader(fileName);
// CONTROLS WHETHER WE SKIP A ROW OR NOT
int RowCount = 0;
// CONTROLS WHETHER WE CREATE COLUMNS OR NOT
bool hasColumns = false;
string[] ColumnNames = null;
string[] oStreamDataValues = null;
//using while loop read the stream data till end
while (!oStreamReader.EndOfStream)
{
String oStreamRowData = oStreamReader.ReadLine().Trim();
if (oStreamRowData.Length > 0)
{
oStreamDataValues = oStreamRowData.Split(';');
//Bcoz the first row contains column names, we will poluate
//the column name by
//reading the first row and RowCount-0 will be true only once
// CHANGE TO CHECK FOR COLUMNS CREATED
if (!hasColumns)
{
ColumnNames = oStreamRowData.Split(';');
//using foreach looping through all the column names
foreach (string csvcolumn in ColumnNames)
{
DataColumn oDataColumn = new DataColumn(csvcolumn.ToUpper(), typeof(string));
//setting the default value of empty.string to newly created column
oDataColumn.DefaultValue = string.Empty;
//adding the newly created column to the table
oDataTable.Columns.Add(oDataColumn);
}
// SET COLUMNS CREATED
hasColumns = true;
// SET RowCount TO 0 SO WE KNOW TO SKIP COLUMNS LINE
RowCount = 0;
}
else
{
// IF RowCount IS 0 THEN SKIP COLUMN LINE
if (RowCount++ == 0) continue;
//creates a new DataRow with the same schema as of the oDataTable
DataRow oDataRow = oDataTable.NewRow();
//using foreach looping through all the column names
for (int i = 0; i < ColumnNames.Length; i++)
{
oDataRow[ColumnNames[i]] = oStreamDataValues[i] == null ? string.Empty : oStreamDataValues[i].ToString();
}
//adding the newly created row with data to the oDataTable
oDataTable.Rows.Add(oDataRow);
}
}
}
//close the oStreamReader object
oStreamReader.Close();
//release all the resources used by the oStreamReader object
oStreamReader.Dispose();
}
return oDataTable;
}
I am thankful for everyone who is willing to help. And Thanks for reading this far!
Sincerely yours

If I understood you right, there is a strict parsing there like this:
string OpenAndParse(string filename, bool firstFile=false)
{
var lines = File.ReadAllLines(filename);
var parsed = lines.Select(l => l.Split(';')).ToArray();
var header = $"{parsed[0][0]};{parsed[1][0]};{parsed[2][0]};{parsed[1][0]}\n";
var data = $"{parsed[0][1]};{parsed[1][1]};{parsed[2][1]};{parsed[1][2]}\n";
return firstFile
? $"{header}{data}"
: $"{data}";
}
Where it would return - if first file:
Header1;Header2;Header3;Header2
Value1;Value2;Value3;Value4
if not first file:
Value1;Value2;Value3;Value4
If I am correct, rest is about running this against a list file of files and joining the results in an output file.
EDIT: Against a directory:
void ProcessFiles(string folderName, string outputFileName)
{
bool firstFile = true;
foreach (var f in Directory.GetFiles(folderName))
{
File.AppendAllText(outputFileName, OpenAndParse(f, firstFile));
firstFile = false;
}
}
Note: I missed you want a DataTable and not an output file. Then you could simply create a list and put the results into that list making the list the datasource for your datatable (then why would you use semicolons in there? Probably all you need is to simply attach the array values to a list).

(Adding as another answer just to make it uncluttered)
void ProcessMyFiles(string folderName)
{
List<MyData> d = new List<MyData>();
var files = Directory.GetFiles(folderName);
foreach (var file in files)
{
OpenAndParse(file, d);
}
string[] headers = GetHeaders(files[0]);
DataGridView dgv = new DataGridView {Dock=DockStyle.Fill};
dgv.DataSource = d;
dgv.ColumnAdded += (sender, e) => {e.Column.HeaderText = headers[e.Column.Index];};
Form f = new Form();
f.Controls.Add(dgv);
f.Show();
}
string[] GetHeaders(string filename)
{
var lines = File.ReadAllLines(filename);
var parsed = lines.Select(l => l.Split(';')).ToArray();
return new string[] { parsed[0][0], parsed[1][0], parsed[2][0], parsed[1][0] };
}
void OpenAndParse(string filename, List<MyData> d)
{
var lines = File.ReadAllLines(filename);
var parsed = lines.Select(l => l.Split(';')).ToArray();
var data = new MyData
{
Col1 = parsed[0][1],
Col2 = parsed[1][1],
Col3 = parsed[2][1],
Col4 = parsed[1][2]
};
d.Add(data);
}
public class MyData
{
public string Col1 { get; set; }
public string Col2 { get; set; }
public string Col3 { get; set; }
public string Col4 { get; set; }
}

I don't know if this is the best way to do this. But what i would have done in your case, is to rewrite the CSV's the conventionnal way while reading all the files, then create a stream containing the new CSV created.
It would look like something like this :
var csv = new StringBuilder();
csv.AppendLine("Header1;Header2;Header3;Header4");
foreach (var item in file)
{
var newLine = string.Format("{0},{1},{2},{3}", item.value1, item.value2, item.value3, item.value4);
csv.AppendLine(newLine);
}
//Create Stream
MemoryStream stream = new MemoryStream();
StreamReader reader = new StreamReader(stream);
//Fill your data table here with your values
Hope this will help.

How to create dynamic buttons based on an arraylist

I'm having some trouble creating a foreach loop that creates buttons dynamically based on a List that is inside the NamesDA class.
I'm getting errors such as: Cannot convert type 'Program1.Names' to 'int'. I've tried what I know to fix the conversion error, but I don't know the correct way to do it.
Edit 1: allNames is an array list inside NamesDA that reads a csv file.
It returns a list of strings and int's, which then they are to be used to create the buttons and represent them.
Edit 2: The foreach loop problem is solved now, but I'm unable to get the values of column[0] for button text and column[1] for button tag.
The NamesDA class:
private const string path = "names.csv";
public static List<Names> GetNames()
{
StreamReader textIn = new StreamReader(new FileStream(path, FileMode.OpenOrCreate, FileAccess.Read));
List<Names> allNames = new List<Names>();
while (textIn.Peek() != -1)
{
string row = textIn.ReadLine();
string[] columns = row.Split(',');
allNames.Add(new Names(columns[0].ToString(), Convert.ToInt16(columns[1])));
}
textIn.Close();
return allNames;
}
The form:
int startTop = 20;
int startLeft = 17;
allNames = NamesDA.GetNames(); //calling the method in the NamesDA class
foreach (int x in allNames) {
names[x] = new Button();
tempButton.Text = ""; //based on the list column[0]
tempButton.Tag = ""; //based on the list column[1]
names[x].Location = new System.Drawing.Point(startTop + (x * 95), startLeft);
listView.Controls.Add(names[x]);
}

From the Updates it is clear that allNames is a List<Names>, where Names is a class contains two properties/fields one is of type int(let it be _id) and the another one is of type string(let it be _name). So you have to re create the loop as like the following:
Updates : You can Set the button location as well, if you need that you have to define two integer properties in the class(let it be int positionX=10 and int PositionY=30) Now take a look at the updated code:
int nextLeft=30;
foreach (Names name in allNames)
{
Button tempButton = new Button();
tempButton.Name = name._id;
tempButton.Text = name._name;
tempButton.Location = new System.Drawing.Point(name.positionX + nextLeft,name.positionY);
listView.Controls.Add(tempButton);
nextLeft+=30;
}

Each row iterate through n columns

I have the code below. To explain there will always be values for the 'tl' variable.
At the moment its hard coded to always assume 4 columns in the row, but I want to make it work based on the count of the columns and make it build the levels based on how many columns there are, but there also needs to be a value in the column.
So at the moment if there is a value in column 2, it will build the 'ltwo' variable, and then if there is a value in column 3 it does the 'lthree'.
I want to make it build as many levels as it needs to so im not repeating code and having the same code over and over.
public static List<AdditionalPropertyType> SQLAddPropsStructured(DataTable dataTable, List<AdditionalPropertyType> currentadditionalproperties)
{
foreach (DataRow row in dataTable.Rows)
{
var tl = new AdditionalPropertyType
{
Name = row[0].ToString(),
Value = row[1].ToString()
};
if (!String.IsNullOrEmpty(row[2].ToString()))
{
var ltwo = new AdditionalPropertyType
{
Name = row[2].ToString()
};
var ltwolist = new List<AdditionalPropertyType>();
ltwolist.Add(tl);
ltwo.AdditionalProperties = ltwolist;
if (!String.IsNullOrEmpty(row[3].ToString()))
{
var lthree = new AdditionalPropertyType
{
Name = row[3].ToString()
};
var lthreelist = new List<AdditionalPropertyType>();
lthreelist.Add(ltwo);
lthree.AdditionalProperties = lthreelist;
currentadditionalproperties.Insert(0, lthree);
}
else
currentadditionalproperties.Insert(0, ltwo);
}
else
currentadditionalproperties.Insert(0, tl);
}
return currentadditionalproperties;
}

You can get the columns using the Columns property of the DataTable:
foreach (DataRow row in dataTable.Rows)
{
foreach(DataColumn column in dataTable.Columns)
{
Trace.WriteLine(column.ColumnName + " = " + row[column]);
}
}
You probably want to do something like this: (written on the websites, some minor typos can be present)
You need to iterate the additional columns and check if there is a value present. When there is a value, create a backup reference and renew your property.
public static List<AdditionalPropertyType> SQLAddPropsStructured(DataTable dataTable, List<AdditionalPropertyType> currentadditionalproperties)
{
// check if there are atleast 2 columns defined
if(dataTable.Columns.Count < 2)
throw new Exception("At least two columns are required");
// The result
var currentadditionalproperties = new List<AdditionalPropertyType>();
// iterate the rows
foreach (DataRow row in dataTable.Rows)
{
// create the base property
var tl = new AdditionalPropertyType
{
Name = row[0].ToString(),
Value = row[1].ToString()
};
// check the rest of the columns for additional names
foreach(int index=2;index<dataTable.Columns.Count;index++)
{
var columnValue = row[index].ToString();
// if the column is empty, discontinue the iteration
if(String.IsNullOrEmpty(columnValue))
break;
// create a backup reference.
var previous = tl;
// create a new AdditionalPropertyType
var tl = new AdditionalPropertyType { Name = columnValue };
// Create the list
tl.AdditionalProperties = new List<AdditionalPropertyType>();
// add the previous (backup reference)
tl.AdditionalProperties.Add(previous);
}
// insert the 'chain' of additional properties on the list at possition 0
currentadditionalproperties.Insert(0, tl);
}
// return the list
return currentadditionalproperties;
}

The first step is to reverse your condition and make use of the keyword continue
public static List<AdditionalPropertyType> SQLAddPropsStructured(DataTable dataTable, List<AdditionalPropertyType> currentadditionalproperties)
{
foreach (DataRow row in dataTable.Rows)
{
var tl = new AdditionalPropertyType
{
Name = row[0].ToString(),
Value = row[1].ToString()
};
if (String.IsNullOrEmpty(row[2].ToString())){
currentadditionalproperties.Insert(0, tl);
continue;
}
var ltwo = new AdditionalPropertyType
{
Name = row[2].ToString()
};
var ltwolist = new List<AdditionalPropertyType>();
ltwolist.Add(tl);
ltwo.AdditionalProperties = ltwolist;
if (String.IsNullOrEmpty(row[3].ToString())) {
currentadditionalproperties.Insert(0, ltwo);
continue;
}
var lthree = new AdditionalPropertyType
{
Name = row[3].ToString()
};
var lthreelist = new List<AdditionalPropertyType>();
lthreelist.Add(ltwo);
lthree.AdditionalProperties = lthreelist;
currentadditionalproperties.Insert(0, lthree);
}
return currentadditionalproperties;
}
Now, the code is clearer. The next step is to collect the repeating cases. Note the second case onward is repeating. Thus, do further simplification:
public static List<AdditionalPropertyType> SQLAddPropsStructured(DataTable dataTable, List<AdditionalPropertyType> currentadditionalproperties)
{
foreach (DataRow row in dataTable.Rows)
{
var tlprev = new AdditionalPropertyType
{
Name = row[0].ToString(),
Value = row[1].ToString()
};
bool isTlUpdated = true;
for (int i = 2; i <= 3; ++i) { //change this according to your need
if (String.IsNullOrEmpty(row[i].ToString()) && isTlUpdated){
currentadditionalproperties.Insert(0, tlprev);
isTlUpdated = false;
break; //note that this will now change to break to break from the current for-loop
}
var lnext = new AdditionalPropertyType
{
Name = row[i].ToString()
};
var lnextlist = new List<AdditionalPropertyType>();
lnextlist.Add(tlprev);
lnext.AdditionalProperties = lnextlist;
tlprev = lnext; //need to record this for the next loop or end of the case
isTlUpdated = true;
}
if (isTlUpdated) //correction by Jeroen
currentadditionalproperties.Insert(0, tlprev);
}
return currentadditionalproperties;
}
The key is to simplify the code step-by-step

You haven't posted all your code, so I had to guess in a couple of places (such as what the "currentAdditionalProperties" does).
I think that the below code illustrates what you want to do by making the logic extendable depending on how many columns the data table has.
The trick is to just store the "last thing" in a variable, so it can be used for the "current thing". At the end, whatever was the "last thing" is what you want to store in your "currentAdditionalProperties" object. I have commented so you can see the logic.
private List<AdditionalPropertyType> SQLAddPropsStructured(DataTable dataTable)
{
AdditionalPropertyType lastNewType; // to remember the previous new instance
// for all rows...
foreach (DataRow row in dataTable.Rows)
{
// the first type takes name and value from the first two fields
AdditionalPropertyType newType = new AdditionalPropertyType();
newType.Name = row[0].ToString();
newType.Value = row[1].ToString();
// remember this type: it is used as the AdditionalProperties for the NEXT type
lastNewType = newType;
// additional types start from field 2
int field = 2;
// iterate until we find a NULL field.
// If you want to check for the end of the fields rather than a NULL value, then instead use:
// while(field < dataTable.Columns.Count)
while(!String.IsNullOrEmpty(row[field].ToString()))
{
// create new type
var newSubType = new AdditionalPropertyType();
// get name
Name = row[field].ToString();
// new type takes the PREVIOUS type as its additional parameters
List<AdditionalPropertyType> propertyData = new List<AdditionalPropertyType>();
propertyData.Add(lastNewType);
newSubType.AdditionalProperties = propertyData;
// remember THIS type for the NEXT type
lastNewType = newSubType;
// process next field (if valid)
field++;
}
// put the last set of properties found into the current properties
currentAdditionalProperties.Insert(0, lastNewType);
return currentAdditionalProperties;
}
}

Remove a certain value from string which keeps on changing

I'm trying to make a utility to generate an insert script of SQL tables along with relational table.
I got all the values in C#.
Now I want to remove the one column name and its value from the script.most probably the identity column.
For example: the string I have (which keeps on changing with table name and varies)
INSERT INTO Core.Customers ([customerId], [customername], [customeradress],[ordernumber])
VALUES (123, N'Rahul', N'244 LIZ MORN', 2334)
NOW I know I have to remove CustomerId (sometimes need to be replaces with #somevariable).
Please give me an efficient way how to retrieve customerId value and deleting column name and value.
I was looking for a method to find column value by column Name.
What I am doing is below - I know it's inefficient and can cause problem but for now it is working smoothly.
public string GetColumnValueToForDesiredColumnName(string row, TableInfo tableinfo, string NameofColumnTOfindvalueFor)
{
Dictionary<string, string> ValueTypedictionary = new Dictionary<string, string>();
string value = null;
// this code is quite messy - I need some suggestion on this one
string[] plusseperatedinsert = row.Replace("INSERT " + "[" + tableinfo.Schema + "].[" + tableinfo.TableName + "]", string.Empty).Trim().Replace("VALUES", "+").Split('+');
string[] columnvalues = plusseperatedinsert[0].Replace("(", string.Empty).Replace(")", string.Empty).Replace("(", string.Empty).Replace("[", string.Empty).Replace("]", string.Empty).Trim().Split(',');
string[] valuesfield = plusseperatedinsert[1].Replace("(", string.Empty).Replace(")", string.Empty).Replace("(", string.Empty).Replace("[", string.Empty).Replace("]", string.Empty).Trim().Split(',');
for (int index = 0; index < columnvalues.Length; index++)
{
ValueTypedictionary.Add(columnvalues[index], valuesfield[index]);
}
ValueTypedictionary.TryGetValue(NameofColumnTOfindvalueFor, out value);
return value;
}
This returns 123 as value.
And then I am using
string.Replace("[customerId],", string.empty).Replace(123, string.empty);

Create a special clas InsertQuery which stores pairs of column names with column values and then if you always need to remove or change an Id of a table you will know that it is on the first index of a list/array/whatever you use to store these pairs.
Define a method for removing this column and you are good to go.
So here is the code. You will probably change it somehow, it is just a proof of concept.
public class InsertQuery
{
private class Column
{
public string Name { get; set; }
public string Value { get; set; }
}
private readonly List<Column> columns = new List<Column>();
private readonly string tableName;
public InsertQuery(string tableName)
{
this.tableName = tableName;
}
public void AddColumn(string name, string value)
{
columns.Add(new Column { Name = name, Value = value });
}
public string RemoveColumnByName(string columnName)
{
var column = columns.First(c => c.Name == columnName);
var value = column.Value;
columns.Remove(column);
return value;
}
public string RemoveIdColumn()
{
var column = columns.First();
var value = column.Value;
columns.RemoveAt(0);
return value;
}
public override string ToString()
{
var sb = new StringBuilder();
sb.Append("INSERT INTO ");
sb.Append(tableName);
sb.Append(" (");
// append first all column names and then their values
return sb.ToString();
}
}
Trust me. Building such a tool using just string operations is not quite a good idea. In time you will want to add more functionality and you will be stuck with code that can be hardly extended. Encapsulation is a way to go.