c# combobox fill from database

| 2017/10/05 03:18
To get only the unique /distinct/ data table records from any database connected to DataSet in C# project and to put them inside combobox.Fill the table adapter with the records from database.
Create a view containing the database table
DataView view = new DataView(this.myDB_DataSet.myDBTable);

Copy only the distinct records to new data table.

Get latest date record - SQL query

| 2017/10/05 03:02
To return the latest record (one record only) from data base table where one of the fields is in Date/Time format:
SELECT TOP 1 * FROM table_name ORDER BY date_time_column_name DESC

c# combobox set selected item by item's text

| 2017/10/05 02:52
C# Combobox defined with name my_combobox
private System.Windows.Forms.ComboBox my_combobox;

Define string variable with the text of the combobox item that has to be selected. For example, if the combobox items have text values "item_a" "item_b" "item_c" ... and the item which text is "item_b" has to be selected

C# - Get database connection string from Web.config file

| 2017/10/05 02:45

To get the database connection string from IIS Web.config file using C# code, include System.Configuration directive and then create a string variable to assign the connection string like this:
using System.Configuration;
string connStr = ConfigurationManager.
If “ConfigurationManager” is not recognized you will need to add reference to: "System.Configuration".See: C# - How to add reference to project


C# Textbox - enter only positive numbers on KeyPress event in Windows form application

| 2017/10/05 02:27

To prevent users from entering incorrect data in Windows form application, set restriction to allow only specific characters to be entered in the text box.This example uses KeyPress event to monitor the users input and to apply the restriction required.To avoid code duplication in Windows multiform applications for example, a separate class file is created “CommonFunctions.cs”.
The function to allow only numbers in textbox control is named InputNumbers.
For each Windows form, create a single KeyPress event and call the InputNumbers function inside it.