The System.Author Windows property is a multiple value string. Windows Search returns this value as an array of strings in a DataColumn. (The column's data-type is string[] or String().) When I call the WriteXML method on the resulting data-table, I get the following InvalidOperationException exception.
Is there a way to specify the data-table's xml-serializer to use for specific columns or specific data-types?
Basically, how can I make WriteXML work with this data-table?
System.InvalidOperationException:
Type System.String[] does not
implement IXmlSerializable interface
therefore can not proceed with
serialization.
You could easily copy your DataTable changing the offending Authors column to a String and joing the string[] data with a proper delimiter like "|" or "; ".
DataTable xmlFriendlyTable = oldTable.Clone();
xmlFriendlyTable.Columns["Author"].DataType = typeof(String);
xmlFriendlyTable.Columns["Author"].ColumnMapping = MappingType.Element;
foreach(var row in oldTable.Rows) {
object[] rowData = row.ItemArray;
object[] cpyRowData = new object[rowData.Length];
for(int i = 0; i<rowData.Length; i++) {
if(rowData[i] != null && rowData[i].GetType() == typeof(String[])) {
cpyRowData[i] = String.Join("; ", (rowData[i] as String[]));
} else {
cpyRowData[i] = rowData[i];
}
xmlFriendlyTable.Rows.Add(cpyRowData);
}
}
xmlFriendlyTable.WriteXml( ... );
NOTE Wrote the above in the web browser, so there may be syntax errors.
Related
In my code has an issue but I can't see what issue in this. Column names are same word by word and it is working, If I use 1 column in csv file but when I try out more then 2-3 column fields it is giving the error below. I have checked read lots of article so I can't fix the error. What can be happen with is this lines. DB already was created with similar fields.
private void DBaktar()
{
string SQLServerConnectionString = "Server =.\\SQLEXPRESS; Database = Qiti; User Id = sa; Password = 7731231xx!!;";
string CSVpath = #"D:\FTP\"; // CSV file Path
string CSVFileConnectionString = String.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source={0};;Extended Properties=\"text;HDR=Yes;FMT=Delimited\";", CSVpath);
var AllFiles = new DirectoryInfo(CSVpath).GetFiles("*.CSV");
string File_Name = string.Empty;
foreach (var file in AllFiles)
{
try
{
DataTable dt = new DataTable();
using (OleDbConnection con = new OleDbConnection(CSVFileConnectionString))
{
con.Open();
var csvQuery = string.Format("select * from [{0}]", file.Name);
using (OleDbDataAdapter da = new OleDbDataAdapter(csvQuery, con))
{
da.Fill(dt);
}
}
using (SqlBulkCopy bulkCopy = new SqlBulkCopy(SQLServerConnectionString))
{
bulkCopy.ColumnMappings.Add("LKod", "LKod");
bulkCopy.ColumnMappings.Add("info", "info");
bulkCopy.ColumnMappings.Add("Codex", "Codex");
bulkCopy.ColumnMappings.Add("LthNo", "LthNo");
bulkCopy.ColumnMappings.Add("Datein", "Datein");
bulkCopy.DestinationTableName = "U_Tik";
bulkCopy.BatchSize = 0;
bulkCopy.EnableStreaming = true;
bulkCopy.WriteToServer(dt);
bulkCopy.Close();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
Error exception;
The given ColumnName 'LKod' does not match up with any column in data
source.
ex.StackTrace;
at
System.Data.SqlClient.SqlBulkCopy.WriteRowSourceToServerCommon(Int32
columnCount) at
System.Data.SqlClient.SqlBulkCopy.WriteRowSourceToServerAsync(Int32
columnCount, CancellationToken ctoken) at
System.Data.SqlClient.SqlBulkCopy.WriteToServer(DataTable table,
DataRowState rowState) at
System.Data.SqlClient.SqlBulkCopy.WriteToServer(DataTable table)
Some information can be found here: https://sqlbulkcopy-tutorial.net/columnmapping-does-not-match
Cause
You didn't provide any ColumnMappings, and there is more column in the source than in the destination.
You provided an invalid column name for the source.
You provided an invalid column name for the destination.
Solution
ENSURE to provide a ColumnMappings
ENSURE all values for source column name are valid and case sensitive.
ENSURE all values for destination column name are valid and case sensitive.
MAKE the source case insensitive
I have found a solution and working 100% true.. The link below, I hope become a path who need that.
https://johnnycode.com/2013/08/19/using-c-sharp-sqlbulkcopy-to-import-csv-data-sql-server/
Need to sort/order a list of data based on an undetermined number of columns (1 or more).
What i'm trying to do is loop through the desired columns and add an OrderBy or ThenBy based on their number to the query'd list, but i'm unsuccessful...
Done this, but it doesn't compile:
var query = GetAllItems(); //returns a IQueriable list of items
//for each selected column
for (int i = 0; i < param.Columns.Length; i++)
{
if (i == 0)
{
query = query.OrderBy(x => x.GetType().GetProperty(param.Columns[i].Name));
}
else
{
//ERROR: IQueriable does not contain a definition for "ThenBy" and no extension method "ThenBy"...
query = query.ThenBy(x => x.GetType().GetProperty(param.Columns[i].Data));
}
}
How can i resolve this issue? Or any alternative to accomplish this requirement?
SOLUTION: #Dave-Kidder's solution is well thought and resolves the compile errors i had. Just one problem, OrderBy only executes (actually sorts the results) after a ToList() cast. This is an issue because i can't convert a ToList back to an IOrderedQueryable.
So, after some research i came across a solution that resolve all my issues.
Microsoft assembly for the .Net 4.0 Dynamic language functionality: https://github.com/kahanu/System.Linq.Dynamic
using System.Linq.Dynamic; //need to install this package
Updated Code:
var query = GetAllItems(); //returns a IQueriable list of items
List<string> orderByColumnList = new List<string>(); //list of columns to sort
for (int i = 0; i < param.Columns.Length; i++)
{
string column = param.Columns[i].Name;
string direction = param.Columns[i].Dir;
//ex.: "columnA ASC"
string orderByColumn = column + " " + direction;
//add column to list
orderByColumnList.Add(orderBy);
}
//convert list to comma delimited string
string orderBy = String.Join(",", orderByColumnList.ToArray());
//sort by all columns, yay! :-D
query.OrderBy(orderBy).ToList();
The problem is that ThenBy is not defined on IQueryable, but on the IOrderedQueryable interface (which is what IQueryable.OrderBy returns). So you need to define a new variable for the IOrderedQueryable in order to do subsequent ThenBy calls. I changed the original code a bit to use System.Data.DataTable (to get a similar structure to your "param" object). The code also assumes that there is at least one column in the DataTable.
// using System.Data.DataTable to provide similar object structure as OP
DataTable param = new DataTable();
IQueryable<DataTable> query = new List<DataTable>().AsQueryable();
// OrderBy returns IOrderedQueryable<TSource>, which is the interface that defines
// "ThenBy" so we need to assign it to a different variable if we wish to make subsequent
// calls to ThenBy
var orderedQuery = query.OrderBy(x => x.GetType().GetProperty(param.Columns[0].ColumnName));
//for each other selected column
for (int i = 1; i < param.Columns.Count; i++)
{
orderedQuery = orderedQuery.ThenBy(x => x.GetType().GetProperty(param.Columns[i].ColumnName));
}
you should write ThenBy after OrderBy like this:
query = query
.OrderBy(t=> // your condition)
.ThenBy(t=> // next condition);
I have some word templates(maybe thousands). Each template has merge fields which will be filled from database. I don`t like writing separate code for every template and then build the application and deploy it whenever a template is changed or a field on the template is added!
Instead, I'm trying to define all merge fields in a separate xml file and for each field I want to write the "query" which will be called when needed. EX:
mergefield1 will call query "Case.Parties.FirstOrDefault.NameEn"
mergefield2 will call query "Case.CaseNumber"
mergefield3 will call query "Case.Documents.FirstOrDefault.DocumentContent.DocumentType"
Etc,
So, for a particular template I scan its merge fields, and for each merge field I take it`s "query definition" and make that request to database using EntityFramework and LINQ. Ex. it works for these queries: "TimeSlots.FirstOrDefault.StartDateTime" or
"Case.CaseNumber"
This will be an engine which will generate word documents and fill it with merge fields from xml. In addition, it will work for any new template or new merge field.
Now, I have worked a version using reflection.
public string GetColumnValueByObjectByName(Expression<Func<TEntity, bool>> filter = null, string objectName = "", string dllName = "", string objectID = "", string propertyName = "")
{
string objectDllName = objectName + ", " + dllName;
Type type = Type.GetType(objectDllName);
Guid oID = new Guid(objectID);
dynamic Entity = context.Set(type).Find(oID); // get Object by Type and ObjectID
string value = ""; //the value which will be filled with data from database
IEnumerable<string> linqMethods = typeof(System.Linq.Enumerable).GetMethods(BindingFlags.Static | BindingFlags.Public).Select(s => s.Name).ToList(); //get all linq methods and save them as list of strings
if (propertyName.Contains('.'))
{
string[] properies = propertyName.Split('.');
dynamic object1 = Entity;
IEnumerable<dynamic> Child = new List<dynamic>();
for (int i = 0; i < properies.Length; i++)
{
if (i < properies.Length - 1 && linqMethods.Contains(properies[i + 1]))
{
Child = type.GetProperty(properies[i]).GetValue(object1, null);
}
else if (linqMethods.Contains(properies[i]))
{
object1 = Child.Cast<object>().FirstOrDefault(); //for now works only with FirstOrDefault - Later it will be changed to work with ToList or other linq methods
type = object1.GetType();
}
else
{
if (linqMethods.Contains(properies[i]))
{
object1 = type.GetProperty(properies[i + 1]).GetValue(object1, null);
}
else
{
object1 = type.GetProperty(properies[i]).GetValue(object1, null);
}
type = object1.GetType();
}
}
value = object1.ToString(); //.StartDateTime.ToString();
}
return value;
}
I`m not sure if this is the best approach. Does anyone have a better suggestion, or maybe someone has already done something like this?
To shorten it: The idea is to make generic linq queries to database from a string like: "Case.Parties.FirstOrDefault.NameEn".
Your approach is very good. I have no doubt that it already works.
Another approach is using Expression Tree like #Egorikas have suggested.
Disclaimer: I'm the owner of the project Eval-Expression.NET
In short, this library allows you to evaluate almost any C# code at runtime (What you exactly want to do).
I would suggest you use my library instead. To keep the code:
More readable
Easier to support
Add some flexibility
Example
public string GetColumnValueByObjectByName(Expression<Func<TEntity, bool>> filter = null, string objectName = "", string dllName = "", string objectID = "", string propertyName = "")
{
string objectDllName = objectName + ", " + dllName;
Type type = Type.GetType(objectDllName);
Guid oID = new Guid(objectID);
object Entity = context.Set(type).Find(oID); // get Object by Type and ObjectID
var value = Eval.Execute("x." + propertyName, new { x = entity });
return value.ToString();
}
The library also allow you to use dynamic string with IQueryable
Wiki: LINQ-Dynamic
I'm using entity framework 4.
I have a stored procedure that just updates one value in my table, namely the application state ID. So I created a stored procedure that looks like this:
ALTER PROCEDURE [dbo].[UpdateApplicationState]
(
#ApplicationID INT,
#ApplicationStateID INT
)
AS
BEGIN
UPDATE
[Application]
SET
ApplicationStateID = #ApplicationStateID
WHERE
ApplicationID = #ApplicationID;
END
I created a function import called UpdateApplicationState. I had initially set its return type to null, but then it wasn't created in the context. So I changed its return type to int. Now it was created in the context. Is it wise to return something from my stored procedure?
Here is my method in my ApplicationRepository class:
public void UpdateApplicationState(int applicationID, int applicationStateID)
{
var result = context.UpdateApplicationState(applicationID, applicationStateID);
}
Here is my calling code to this method in my view:
applicationRepository.UpdateApplicationState(id, newApplicationStateID);
When I run it then I get the following error:
The data reader returned by the store
data provider does not have enough
columns for the query requested.
Any idea/advise on what I can do to get this to work?
Thanks
To get POCO to work with function imports that return null, you can customize the .Context.tt file like this.
Find the "Function Imports" named region (the section that starts with region.Begin("Function Imports"); and ends with region.End();) in the .Context.tt file and replace that whole section with the following:
region.Begin("Function Imports");
foreach (EdmFunction edmFunction in container.FunctionImports)
{
var parameters = FunctionImportParameter.Create(edmFunction.Parameters, code, ef);
string paramList = String.Join(", ", parameters.Select(p => p.FunctionParameterType + " " + p.FunctionParameterName).ToArray());
var isReturnTypeVoid = edmFunction.ReturnParameter == null;
string returnTypeElement = String.Empty;
if (!isReturnTypeVoid)
returnTypeElement = code.Escape(ef.GetElementType(edmFunction.ReturnParameter.TypeUsage));
#>
<# if (isReturnTypeVoid) { #>
<#=Accessibility.ForMethod(edmFunction)#> void <#=code.Escape(edmFunction)#>(<#=paramList#>)
<# } else { #>
<#=Accessibility.ForMethod(edmFunction)#> ObjectResult<<#=returnTypeElement#>> <#=code.Escape(edmFunction)#>(<#=paramList#>)
<# } #>
{
<#
foreach (var parameter in parameters)
{
if (!parameter.NeedsLocalVariable)
{
continue;
}
#>
ObjectParameter <#=parameter.LocalVariableName#>;
if (<#=parameter.IsNullableOfT ? parameter.FunctionParameterName + ".HasValue" : parameter.FunctionParameterName + " != null"#>)
{
<#=parameter.LocalVariableName#> = new ObjectParameter("<#=parameter.EsqlParameterName#>", <#=parameter.FunctionParameterName#>);
}
else
{
<#=parameter.LocalVariableName#> = new ObjectParameter("<#=parameter.EsqlParameterName#>", typeof(<#=parameter.RawClrTypeName#>));
}
<#
}
#>
<# if (isReturnTypeVoid) { #>
base.ExecuteFunction("<#=edmFunction.Name#>"<#=code.StringBefore(", ", String.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray()))#>);
<# } else { #>
return base.ExecuteFunction<<#=returnTypeElement#>>("<#=edmFunction.Name#>"<#=code.StringBefore(", ", String.Join(", ", parameters.Select(p => p.ExecuteParameterName).ToArray()))#>);
<# } #>
}
<#
}
region.End();
What I'm doing here is instead of ignoring all function imports that return null, I'm creating a method that returns null. I hope this is helpful.
It is because you do not actually returning anything from your stored procedure. Add a line like below to your SP (SELECT ##ROWCOUNT), and it will be executing properly.
BEGIN
...
SELECT ##ROWCOUNT
END
While this solution will address your issue and actually returns the number of effected rows by your SP, I am not clear on why this is an issue for you:
I had initially set its return type to null, but then it wasn't created in the context.
When doing a Function Import, you can select "None" as return type and it will generate a new method on your ObjectContext with a return type of int. This method basically executes a stored procedure that is defined in the data source; discards any results returned from the function; and returns the number of rows affected by the execution.
EDIT: Why a Function without return value is ignored in a POCO Scenario:
Drilling into ObjectContext T4 template file coming with ADO.NET C# POCO Entity Generator reveals why you cannot see your Function in your ObjectContext class: Simply it's ignored! They escape to the next iteration in the foreach loop that generates the functions.
The workaround for this is to change the T4 template to actually generate a method for Functions without return type or just returning something based on the first solution.
region.Begin("Function Imports");
foreach (EdmFunction edmFunction in container.FunctionImports)
{
var parameters = FunctionImportParameter.Create(edmFunction.Parameters, code, ef);
string paramList = String.Join(", ", parameters.Select(p => p.FunctionParameterType + " " + p.FunctionParameterName).ToArray());
// Here is why a Function without return value is ignored:
if (edmFunction.ReturnParameter == null)
{
continue;
}
string returnTypeElement = code.Escape(ef.GetElementType(edmFunction.ReturnParameter.TypeUsage));
...
I'm attempting to parse SQL using the TSql100Parser provided by microsoft. Right now I'm having a little trouble using it the way it seems to be intended to be used. Also, the lack of documentation doesn't help. (example: http://msdn.microsoft.com/en-us/library/microsoft.data.schema.scriptdom.sql.tsql100parser.aspx )
When I run a simple SELECT statement through the parser it returns a collection of TSqlStatements which contains a SELECT statement.
Trouble is, the TSqlSelect statement doesn't contain attributes such as a WHERE clause, even though the clause is implemented as a class. http://msdn.microsoft.com/en-us/library/microsoft.data.schema.scriptdom.sql.whereclause.aspx
The parser does recognise the WHERE clause as such, looking at the token stream.
So, my question is, am I using the parser correctly? Right now the token stream seems to be the most useful feature of the parser...
My Test project:
public static void Main(string[] args)
{
var parser = new TSql100Parser(false);
IList<ParseError> Errors;
IScriptFragment result = parser.Parse(
new StringReader("Select col from T1 where 1 = 1 group by 1;" +
"select col2 from T2;" +
"select col1 from tbl1 where id in (select id from tbl);"),
out Errors);
var Script = result as TSqlScript;
foreach (var ts in Script.Batches)
{
Console.WriteLine("new batch");
foreach (var st in ts.Statements)
{
IterateStatement(st);
}
}
}
static void IterateStatement(TSqlStatement statement)
{
Console.WriteLine("New Statement");
if (statement is SelectStatement)
{
PrintStatement(sstmnt);
}
}
Yes, you are using the parser correctly.
As Damien_The_Unbeliever points out, within the SelectStatement there is a QueryExpression property which will be a QuerySpecification object for your third select statement (with the WHERE clause).
This represents the 'real' SELECT bit of the query (whereas the outer SelectStatement object you are looking at has just got the 'WITH' clause (for CTEs), 'FOR' clause (for XML), 'ORDER BY' and other bits)
The QuerySpecification object is the object with the FromClauses, WhereClause, GroupByClause etc.
So you can get to your WHERE Clause by using:
((QuerySpecification)((SelectStatement)statement).QueryExpression).WhereClause
which has a SearchCondition property etc. etc.
Quick glance around would indicate that it contains a QueryExpression, which could be a QuerySpecification, which does have the Where clause attached to it.
if someone lands here and wants to know how to get the whole elements of a select statement the following code explain that:
QuerySpecification spec = (QuerySpecification)(((SelectStatement)st).QueryExpression);
StringBuilder sb = new StringBuilder();
sb.AppendLine("Select Elements");
foreach (var elm in spec.SelectElements)
sb.Append(((Identifier)((Column)((SelectColumn)elm).Expression).Identifiers[0]).Value);
sb.AppendLine();
sb.AppendLine("From Elements");
foreach (var elm in spec.FromClauses)
sb.Append(((SchemaObjectTableSource)elm).SchemaObject.BaseIdentifier.Value);
sb.AppendLine();
sb.AppendLine("Where Elements");
BinaryExpression binaryexp = (BinaryExpression)spec.WhereClause.SearchCondition;
sb.Append("operator is " + binaryexp.BinaryExpressionType);
if (binaryexp.FirstExpression is Column)
sb.Append(" First exp is " + ((Identifier)((Column)binaryexp.FirstExpression).Identifiers[0]).Value);
if (binaryexp.SecondExpression is Literal)
sb.Append(" Second exp is " + ((Literal)binaryexp.SecondExpression).Value);
I had to split a SELECT statement into pieces. My goal was to COUNT how many record a query will return. My first solution was to build a sub query such as
SELECT COUNT(*) FROM (select id, name from T where cat='A' order by id) as QUERY
The problem was that in this case the order clause raises the error "The ORDER BY clause is not valid in views, inline functions, derived tables, sub-queries, and common table expressions, unless TOP or FOR XML is also specified"
So I built a parser that split a SELECT statment into fragments using the TSql100Parser class.
using Microsoft.Data.Schema.ScriptDom.Sql;
using Microsoft.Data.Schema.ScriptDom;
using System.IO;
...
public class SelectParser
{
public string Parse(string sqlSelect, out string fields, out string from, out string groupby, out string where, out string having, out string orderby)
{
TSql100Parser parser = new TSql100Parser(false);
TextReader rd = new StringReader(sqlSelect);
IList<ParseError> errors;
var fragments = parser.Parse(rd, out errors);
fields = string.Empty;
from = string.Empty;
groupby = string.Empty;
where = string.Empty;
orderby = string.Empty;
having = string.Empty;
if (errors.Count > 0)
{
var retMessage = string.Empty;
foreach (var error in errors)
{
retMessage += error.Identifier + " - " + error.Message + " - position: " + error.Offset + "; ";
}
return retMessage;
}
try
{
// Extract the query assuming it is a SelectStatement
var query = ((fragments as TSqlScript).Batches[0].Statements[0] as SelectStatement).QueryExpression;
// Constructs the From clause with the optional joins
from = (query as QuerySpecification).FromClauses[0].GetString();
// Extract the where clause
where = (query as QuerySpecification).WhereClause.GetString();
// Get the field list
var fieldList = new List<string>();
foreach (var f in (query as QuerySpecification).SelectElements)
fieldList.Add((f as SelectColumn).GetString());
fields = string.Join(", ", fieldList.ToArray());
// Get The group by clause
groupby = (query as QuerySpecification).GroupByClause.GetString();
// Get the having clause of the query
having = (query as QuerySpecification).HavingClause.GetString();
// Get the order by clause
orderby = ((fragments as TSqlScript).Batches[0].Statements[0] as SelectStatement).OrderByClause.GetString();
}
catch (Exception ex)
{
return ex.ToString();
}
return string.Empty;
}
}
public static class Extension
{
/// <summary>
/// Get a string representing the SQL source fragment
/// </summary>
/// <param name="statement">The SQL Statement to get the string from, can be any derived class</param>
/// <returns>The SQL that represents the object</returns>
public static string GetString(this TSqlFragment statement)
{
string s = string.Empty;
if (statement == null) return string.Empty;
for (int i = statement.FirstTokenIndex; i <= statement.LastTokenIndex; i++)
{
s += statement.ScriptTokenStream[i].Text;
}
return s;
}
}
And to use this class simply:
string fields, from, groupby, where, having, orderby;
SelectParser selectParser = new SelectParser();
var retMessage = selectParser.Parse("SELECT * FROM T where cat='A' Order by Id desc",
out fields, out from, out groupby, out where, out having, out orderby);