Contents of the c:\Import Text.txt fileCalcFieldsErrors: IDtCalcFieldErrors;
The CalcFieldsErrors property returns a collection of errors appeared on calculated fields calculation.
Errors can be obtained only after calling one of the following methods: IDtProvider.Fetch, IDtProvider.FetchRows.
Executing the example requires the c:\Import Text.txt file with data in the file system.
Add links to the Dal, Dt, Metabase system assemblies.
Contents of the c:\Import Text.txt file
Sub UserProc;
Var
DTProvider: IDtTextProvider;
Errors: IDtCalcFieldErrors;
Error: IDtCalcFieldError;
fields: IdtFieldDefinitions;
field: IdtFieldDefinition;
i: Integer;
v: Array;
data: Variant;
Text: String;
Begin
// Create a data provider
DTProvider := New DtTextProvider.Create;
// Set basic parameters of data provider
DTProvider.FormatType := DtTextFormatType.Delimited;
DTProvider.RangeHasHeader := True;
DTProvider.AutoFillFieldsMode := DtAutoFillFieldsMode.DataRow;
DTProvider.TypeGuessRows := 10;
DTProvider.Metabase := MetabaseClass.Active;
DTProvider.DelimitedColumnDelimiter := ";";
DTProvider.Encoding := "WIN";
DTProvider.DelimitedTextQualifier := """";
// Specify the file, from which data will be taken
DtProvider.File := "c:\Import Text.txt";
// Get data provider fields from file
DTProvider.FieldsFromFile;
fields := DTProvider.Fields;
// Specify data type for field with the 1 index from data provider
fields.Item(1).DataType := DbDataType.Integer;
// Add a new calculated field to data provider
field := fields.Add;
field.Name := "CalcField";
field.DataType := DbDataType.Integer;
// Set expression for calculation of field value
field.Expression.AsString := fields.Item(1).Name + "+6";
// Set parameters for handling errors occurred during calculation of calculated fields
Errors := DtProvider.CalcFieldsErrors;
Errors.MaxErrors := -1;
Errors.MaxItems := -1;
// Open data provider
DTProvider.Open;
// Display field names in the console window
Text := "";
For i := 0 To fields.Count - 1 Do
field := fields.Item(i);
Text := Text + (field.Name + "; ");
End For;
Debug.WriteLine(Text);
// Display field values in the console window
While Not DTProvider.Eof Do
DTProvider.Fetch(v);
Text := "";
For i := 0 To v.Length - 1 Do
data := v[i];
Text := Text + (data + " ");
End For;
Debug.WriteLine(Text);
End While;
// Close data provider
DTProvider.Close;
// Display errors in the console window
For Each Error In Errors Do
Debug.WriteLine("In the row No." + Error.Row.ToString + " in the field " + Error.Field + " an error occurred");
Debug.WriteLine("Error text: " + Error.Message);
End For;
End Sub UserProc;
As a result of executing the example data will be loaded from the c:\Import Textt.txt file. The calculated field with the following expression will be created: value of the field with the 1 index from the data source will be increased by six. The results will be displayed to the console. If on formula calculation there are any errors, it will be displayed to the console.
See also: