如何将值存储到查询中的字符串变量中 [英] how to store value in to the string variable from query

问题描述

oleDbConnection cn;

字符串名称;

字符串sirname;

字符串查询=select s_name，来自record_table的s_sirname;

oleDbCommand cmd = new OleDbCommand（query，cn）;



//我想在name和sirname中保存这些选定的值。

oleDbConnection cn;
string name;
string sirname;
string query="select s_name,s_sirname from record_table";
oleDbCommand cmd = new OleDbCommand(query, cn);

//I want to save these selected value in name and sirname.

推荐答案

您必须执行命令，而不是使用读取器，您应该读取结果并存储在变量中。

You have to execute your command, than by using a reader you should read the results and stored in your variables.

IDataReader reader = null;
//
try
{
    reader = cmd.ExecuteReader();
    //
    if (reader.Read())
    {
      name = (string)reader["s_name"];
      sirname = (string)reader["s_sirname"];

    }
}
catch (SqlException exception)
{
    // TO DO!
}
finally
{
    if (reader != null)
        reader.Close();

}

你可以像下面这样使用数据集

字符串名称;

string sirname;

string query =select s_name，from record_table中的s_sirname;

oleDbCommand cmd = new OleDbCommand（query，cn）;

DataSet ds = new DataSet（）;



使用（OleDbConnection connection = new OleDbConnection（connectionString））

使用（OleDbCommand命令=新的OleDbCommand（查询，连接））

使用（OleDbDataAdapter adapter = new OleDbDataAdapter（command））

{

adapter.Fill（ds）;

}

name = ds.tables [0] .rows [0] [s_name]。tostring （）;

sirname = ds.tables [0] .rows [0] [s_sirname]。tostring（）;

you can use dataset like below way
string name;
string sirname;
string query="select s_name,s_sirname from record_table";
oleDbCommand cmd = new OleDbCommand(query, cn);
DataSet ds = new DataSet();

using (OleDbConnection connection = new OleDbConnection(connectionString))
using (OleDbCommand command = new OleDbCommand(query, connection))
using (OleDbDataAdapter adapter = new OleDbDataAdapter(command))
{
adapter.Fill(ds);
}
name=ds.tables[0].rows[0]["s_name"].tostring();
sirname=ds.tables[0].rows[0]["s_sirname"].tostring();

你可以使用datareader或数据集来解决您的问题。下面的一些事情

you can either use datareader or dataset to sovle your issue. some thing like below

string query="select s_name,s_sirname from record_table";
oleDbCommand cmd = new OleDbCommand(query, cn);
oleDbAdepter Da = new oleDbAdepter(cmd);
dataset ds = new dataset();
cn.open();
da.fill(ds);
cn.close();

if(ds!=null && ds.tables[0].rows.count>0)
{
name = ds.tables[0].rows[0]["name"].tostring();
sirname =ds.tables[0].rows[0]["sirname "].tostring(); 
} 

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