如何在C#中创建DataTable以及如何添加行？

Question

如何在C#中创建DataTable？

我喜欢这样:

 DataTable dt = new DataTable();
 dt.clear();
 dt.Columns.Add("Name");
 dt.Columns.Add("Marks");

如何查看DataTable的结构？

现在我想添加ravi for Name和500 for Marks.我怎样才能做到这一点？

Answer 1

这是代码:

DataTable dt = new DataTable(); 
dt.Clear();
dt.Columns.Add("Name");
dt.Columns.Add("Marks");
DataRow _ravi = dt.NewRow();
_ravi["Name"] = "ravi";
_ravi["Marks"] = "500";
dt.Rows.Add(_ravi);

要查看结构,或者我将其重新表示为模式,可以通过执行以下操作将其导出到XML文件.

要仅导出架构/结构,请执行以下操作:

dt.WriteXMLSchema("dtSchemaOrStructure.xml");

此外,您还可以导出数据:

dt.WriteXML("dtDataxml");

Answer 2

您也可以传入一个对象数组,如下所示:

DataTable dt = new DataTable();
dt.Clear();
dt.Columns.Add("Name");
dt.Columns.Add("Marks");
object[] o = { "Ravi", 500 };
dt.Rows.Add(o);

甚至:

dt.Rows.Add(new object[] { "Ravi", 500 });

Answer 3

// Create a DataTable and add two Columns to it
DataTable dt=new DataTable();
dt.Columns.Add("Name",typeof(string));
dt.Columns.Add("Age",typeof(int));

// Create a DataRow, add Name and Age data, and add to the DataTable
DataRow dr=dt.NewRow();
dr["Name"]="Mohammad"; // or dr[0]="Mohammad";
dr["Age"]=24; // or dr[1]=24;
dt.Rows.Add(dr);

// Create another DataRow, add Name and Age data, and add to the DataTable
dr=dt.NewRow();
dr["Name"]="Shahnawaz"; // or dr[0]="Shahnawaz";
dr["Age"]=24; // or dr[1]=24;
dt.Rows.Add(dr);

// DataBind to your UI control, if necessary (a GridView, in this example)
GridView1.DataSource=dt;
GridView1.DataBind();

Answer 4

要添加一行:

DataRow row = dt.NewRow();
row["Name"] = "Ravi";
row["Marks"] = 500;
dt.Rows.Add(row);

要查看结构:

Table.Columns

Answer 5

创建DataTable:

DataTable MyTable = new DataTable(); // 1
DataTable MyTableByName = new DataTable("MyTableName"); // 2

向表中添加列:

 MyTable.Columns.Add("Id", typeof(int));
 MyTable.Columns.Add("Name", typeof(string));

向DataTable方法1添加行:

DataRow row = MyTable.NewRow();
row["Id"] = 1;
row["Name"] = "John";
MyTable.Rows.Add(row);

向DataTable方法2添加行:

MyTable.Rows.Add(2, "Ivan");

向DataTable方法3添加行(通过相同结构从另一个表添加行):

MyTable.ImportRow(MyTableByName.Rows[0]);

向DataTable方法4添加行(从另一个表添加行):

MyTable.Rows.Add(MyTable2.Rows[0]["Id"], MyTable2.Rows[0]["Name"]);

向DataTable方法5添加行(在索引处插入行):

MyTable.Rows.InsertAt(row, 8);

Answer 6

您可以使用DataRow.Add(params object [] values)而不是四行来编写一个衬管.

dt.Rows.Add("Ravi", "500");

在创建新DataTable对象时,似乎没有必要Clear DataTable在下一个语句中.您还可以使用DataTable.Columns.AddRangeon语句添加列.完整的代码将是.

DataTable dt = new DataTable();
dt.Columns.AddRange(new DataColumn[] { new DataColumn("Name"), new DataColumn("Marks") });     
dt.Rows.Add("Ravi", "500");

Answer 7

您可以在一行中添加Row

    DataTable table = new DataTable();
    table.Columns.Add("Dosage", typeof(int));
    table.Columns.Add("Drug", typeof(string));
    table.Columns.Add("Patient", typeof(string));
    table.Columns.Add("Date", typeof(DateTime));

    // Here we add five DataRows.
    table.Rows.Add(25, "Indocin", "David", DateTime.Now);
    table.Rows.Add(50, "Enebrel", "Sam", DateTime.Now);
    table.Rows.Add(10, "Hydralazine", "Christoff", DateTime.Now);
    table.Rows.Add(21, "Combivent", "Janet", DateTime.Now);
    table.Rows.Add(100, "Dilantin", "Melanie", DateTime.Now);

Answer 8

DataTable dt=new DataTable();
Datacolumn Name = new DataColumn("Name");
Name.DataType= typeoff(string);
Name.AllowDBNull=false; //set as null or not the default is true i.e null
Name.MaxLength=20; //sets the length the default is -1 which is max(no limit)
dt.Columns.Add(Name);
Datacolumn Age = new DataColumn("Age", typeoff(int));`

dt.Columns.Add(Age);

DataRow dr=dt.NewRow();

dr["Name"]="Mohammad Adem"; // or dr[0]="Mohammad Adem";
dr["Age"]=33; // or dr[1]=33;
dt.add.rows(dr);
dr=dt.NewRow();

dr["Name"]="Zahara"; // or dr[0]="Zahara";
dr["Age"]=22; // or dr[1]=22;
dt.rows.add(dr);
Gv.DataSource=dt;
Gv.DataBind();

Answer 9

为此,您必须将数据行添加到数据表中.

// Creates a new DataRow with the same schema as the table.
DataRow dr = dt.NewRow();

// Fill the values
dr["Name"] = "Name";
dr["Marks"] = "Marks";

// Add the row to the rows collection
dt.Rows.Add ( dr );

Answer 10

DataTable dt=new DataTable();
DataColumn Name = new DataColumn("Name",typeof(string)); 

dt.Columns.Add(Name);
DataColumn Age = new DataColumn("Age", typeof(int));`

dt.Columns.Add(Age);

DataRow dr=dt.NewRow();

dr["Name"]="Kavitha Reddy"; 
dr["Age"]=24; 
dt.add.Rows(dr);
dr=dt.NewRow();

dr["Name"]="Kiran Reddy";
dr["Age"]=23; 
dt.Rows.add(dr);
Gv.DataSource=dt;
Gv.DataBind();

Answer 11

最简单的方法是创建一个DtaTable

DataTable table = new DataTable
{
    Columns = {
        "Name", // typeof(string) is implied
        {"Marks", typeof(int)}
    },
    TableName = "MarksTable" //optional
};
table.Rows.Add("ravi", 500);