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【C#】 Datatable
C# - Datatable
C# - Datatable
Master the basics of C# DataTables with our comprehensive guide. Learn how to create, populate, and manipulate DataTables in C# for efficient data storage and retrieval. Our step-by-step instructions and examples make it easy to get started with C# DataTables, even if you’re a beginner. Explore the power of DataTables in C# and take your coding skills to the next level.
Table of - contents
No. | Title |
|---|---|
1 | Datatable |
2 | Add Row to Existing DataTable |
3 | Remove Row from Existing DataTable |
4 | Update Row from Existing DataTable |
5 | Clear all Row from Existing DataTable |
1 - Datatable.
C# DataTable is a data structure provided by the .NET Framework that allows you to store and manipulate data in a tabular form. A DataTable object represents a single table in memory, with rows and columns to hold the data.
With a DataTable, you can perform a variety of operations such as filtering, sorting, grouping, and aggregating data. You can also use a DataTable to create relationships between tables, perform joins, and execute queries against the data.
To work with a DataTable in C#, you first create a new instance of the DataTable class, and then define its columns and data. You can add and delete rows, update and retrieve data, and perform various operations on the data as needed.
Example.
// Create a new DataTable
DataTable dt = new DataTable();
// Define the columns
dt.Columns.Add("ID", typeof(int));
dt.Columns.Add("Name", typeof(string));
dt.Columns.Add("Age", typeof(int));
// Add some data
dt.Rows.Add(1, "John", 25);
dt.Rows.Add(2, "Jane", 30);
dt.Rows.Add(3, "Bob", 45);
// Retrieve some data
foreach (DataRow row in dt.Rows)
{
Console.WriteLine("ID: {0}, Name: {1}, Age: {2}", row["ID"], row["Name"], row["Age"]);
}
This creates a new DataTable with three columns (ID, Name, and Age) and adds some data to it. The code then retrieves the data and outputs it to the console.
C# DataTables are a powerful tool for storing, manipulating, and analyzing data, and are widely used in many applications and industries.
2 - Add Row to Existing DataTable.
To add an additional row to an existing DataTable in C#, you can use the NewRow() method of the DataTable object to create a new DataRow object, populate it with data, and add it to the DataTable’s Rows collection.
Example.
// Add a new row
DataRow newRow = dt.NewRow();
newRow["ID"] = 4;
newRow["Name"] = "Sarah";
newRow["Age"] = 28;
dt.Rows.Add(newRow);
In this example, a new DataRow object is created using the NewRow() method, and the values for the ID, Name, and Age columns are set using the indexer notation. The new row is then added to the DataTable’s Rows collection using the Rows.Add() method.
3 - Remove Row from Existing DataTable.
To remove a row from an existing DataTable in C#, you can use the Rows.Remove() method of the DataTable object, passing in the DataRow object that you want to remove.
Example.
// Remove a row
DataRow rowToRemove = dt.Rows.Find(2); // find the row with ID = 2
dt.Rows.Remove(rowToRemove);
In this example, the Rows.Find() method is used to locate the row with an ID of 2, and the resulting DataRow object is assigned to the rowToRemove variable. The Rows.Remove() method is then used to remove the row from the DataTable’s Rows collection.
Note that you can also remove rows using other criteria, such as by index, by primary key value, or by using LINQ to filter the Rows collection.
4 - Update Row from Existing DataTable.
To update an existing row in a DataTable in C#, you can modify the values of the DataRow object and use the Rows[RowIndex].EndEdit() method to apply the changes to the DataTable.
Example.
// Update a row
DataRow rowToUpdate = dt.Rows.Find(2); // find the row with ID = 2
rowToUpdate["Name"] = "Janet"; // change the value of the Name column
rowToUpdate["Age"] = 32; // change the value of the Age column
rowToUpdate.EndEdit(); // apply the changes to the DataTable
In this example, the Rows.Find() method is used to locate the row with an ID of 2, and the resulting DataRow object is assigned to the rowToUpdate variable. The rowToUpdate object is then modified to change the values of the Name and Age columns, and the EndEdit() method is called to apply the changes to the DataTable.
5 - Clear all Row from Existing DataTable.
To clear all the rows from an existing DataTable in C#, you can use the Rows.Clear() method of the DataTable object.
// Clear all rows
dt.Rows.Clear();
In this example, the Rows.Clear() method is called to remove all rows from the DataTable.
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