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[英]How to retrieve data from oracle database in c# windows application without data adapter
[英]Retrieve single user data from oracle database into visual studio C# application
我正在Visual Studio中使用表單來創建應用程序,然后從Oracle數據庫檢索數據。 我的所有部分都在工作,除了獲取單個用戶的數據。 這是該部分的form.cs部分
private void getCustomerStringToolStripMenuItem_Click(object sender, EventArgs
e)
{
Getcuststring g = new Getcuststring();
g.Show();
}
這是我的名為getcuststring.cs的局部類
namespace Assignment
{
public partial class Getcuststring : Form
{
public Getcuststring()
{
InitializeComponent();
}
private void Getcuststring_Load(object sender, EventArgs e)
{
}
private void label1_Click(object sender, EventArgs e)
{
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
private void button1_Click(object sender, EventArgs e)
{
Getting();
}
public void Getting()
{
OracleConnection conn = new OracleConnection();
conn.ConnectionString = "Data Source=(DESCRIPTION =" + "(ADDRESS = (PROTOCOL = TCP)" +
"(HOST = *******)(PORT = 1521))" + "(CONNECT_DATA =" + "(SID = dms)));"
+ "User Id= *****;Password= ******;";
conn.Open();
OracleCommand cmd = new OracleCommand();
cmd.Connection = conn;
cmd.CommandText = "GET_CUST_STRING_FROM_DB";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add("pcustid", OracleDbType.Long).Value = textBox1.Text;
cmd.Parameters.Add("return_value", OracleDbType.Varchar2).Direction = ParameterDirection.ReturnValue;
try
{
cmd.ExecuteNonQuery();
// string result = string.Empty;
var result = cmd.Parameters["result_value"].Value.ToString();
MessageBox.Show(result);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
finally
{
conn.Close();
}
}
}
我的所有其他功能都正常工作,但是在Visual Studio中執行此功能時,每次都會發出異常,表示未找到任何數據,而Oracle數據庫中存在該客戶ID,但它不顯示結果而是引發異常。 那么你能告訴我我哪里錯了,為什么他要給我提供一個例外,說沒有發現數據,而實際上卻存在數據。
這是功能
CREATE OR REPLACE FUNCTION GET_CUST_STRING_FROM_DB(pcustid NUMBER) RETURN
VARCHAR2 AS
vcustid NUMBER;
vcustname VARCHAR2(255);
vcustsales NUMBER;
vcuststatus VARCHAR2(255);
BEGIN
SELECT CUSTID,CUSTNAME,SALES_YTD,STATUS INTO
vcustid,vcustname,vcustsales,vcuststatus
FROM CUSTOMER
WHERE CUSTID = pcustid;
RETURN 'CustID: ' || vcustid || ' Name: ' || vcustname || ' Status: ' ||
vcuststatus || ' SalesYTD: ' || vcustsales;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RAISE_APPLICATION_ERROR(-20021,'Customer ID not found');
WHEN OTHERS THEN
RAISE_APPLICATION_ERROR(-20000,SQLERRM);
END;
我認為這是簡單的錯字,線條
var result = cmd.Parameters["result_value"].Value.ToString();
應該:
var result = cmd.Parameters["return_value"].Value.ToString();
我構建了類似的案例,並在運行它時得到了System.IndexOutOfRangeException
。 糾正錯字問題。 對我有用的整個代碼:
OracleConnection CONNECTION
= new OracleConnection("Data Source=XX;User Id=XX;Password=XX;");
CONNECTION.Open();
OracleCommand cmd = new OracleCommand() { Connection = CONNECTION };
cmd.CommandText = "GET_CUST_STRING_FROM_DB";
cmd.CommandType = System.Data.CommandType.StoredProcedure;
cmd.Parameters.Add("pcustid", OracleType.Double).Value = textBox1.Text;
cmd.Parameters.Add("return_value", OracleType.VarChar, 500).Direction
= System.Data.ParameterDirection.ReturnValue;
cmd.ExecuteNonQuery();
var result = cmd.Parameters["return_value"].Value.ToString();
Console.WriteLine(result);
CONNECTION.Close();
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