OleDbDataReader.GetValues(Object[]) 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
使用当前行的列值来填充对象数组。
public:
override int GetValues(cli::array <System::Object ^> ^ values);
public:
virtual int GetValues(cli::array <System::Object ^> ^ values);
public override int GetValues (object[] values);
public int GetValues (object[] values);
override this.GetValues : obj[] -> int
abstract member GetValues : obj[] -> int
override this.GetValues : obj[] -> int
Public Overrides Function GetValues (values As Object()) As Integer
Public Function GetValues (values As Object()) As Integer
参数
返回
数组中 Object 的实例的数目。
实现
示例
using System;
using System.Data;
using System.Data.OleDb;
class Class1 {
public static void Main() {
using (OleDbConnection connection =
new OleDbConnection("Provider=SQLOLEDB;Data Source=(local);Integrated Security=SSPI;Initial Catalog=Northwind")) {
object[] meta = new object[10];
bool read;
OleDbCommand command = new OleDbCommand("select * from Region", connection);
connection.Open();
OleDbDataReader reader = command.ExecuteReader();
if (reader.Read() == true) {
do {
int NumberOfColums = reader.GetValues(meta);
for (int i = 0; i < NumberOfColums; i++)
Console.Write("{0} ", meta[i].ToString());
Console.WriteLine();
read = reader.Read();
} while (read == true);
}
reader.Close();
}
}
}
Imports System.Data
Imports System.Data.OleDb
Module Module1
Public Sub Main()
Using connection As New OleDbConnection("Provider=SQLOLEDB;Data Source=(local);Integrated Security=SSPI;Initial Catalog=Northwind")
Dim command As New OleDbCommand("select * from Region", connection)
connection.Open()
Dim reader As OleDbDataReader = command.ExecuteReader()
Dim NumberOfColums As Integer
Dim meta As Object() = New Object(10) {}
Dim read As Boolean
If reader.Read() = True Then
Do
NumberOfColums = reader.GetValues(meta)
For i As Integer = 0 To NumberOfColums - 1
Console.Write("{0} ", meta(i).ToString())
Next
Console.WriteLine()
read = reader.Read()
Loop While read = True
End If
reader.Close()
End Using
End Sub
End Module
注解
对于大多数应用程序, GetValues 方法提供了检索所有列的有效方法,而不是单独检索每个列。
可以传递包含 Object 少于结果行中包含的列数的数组。 仅将数组保存 Object 的数据量复制到数组。 还可以传递其 Object 长度大于结果行中包含的列数的数组。
对于 null 数据库列,此方法返回 DBNull。