无法增加数据库的值 [英] Not able to increment the values of the database
本文介绍了无法增加数据库的值的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我想在每次点击按钮时增加数据库值。
我尝试过的事情：
使用System;
使用System.Collections.Generic;使用System.ComponentModel
;
使用System.Data;使用System.Drawing
;
使用System.Linq;
使用System.Text;
使用System.Threading.Tasks;
使用System.Windows.Forms;
使用System.Data.SqlClient;
命名空间online_test
{
公共部分类Form1：表格
{
int incre = 0;
public Form1（）
{
InitializeComponent（）;
radioButton1.TabStop = false;
radioButton2.TabStop = false;
radioButton3.TabStop = false;
radioButton4.TabStop = false;
// qn1（）;
}
private void Form1_Load（object sender，EventArgs e）
{
// string source_1 = @DataSource =（LocalDB）\ MSSQLLocalDB; + @AttachDbFilename = C：\Users\NASH\Documents\Visual Studio 2015 \Projects\C＃\ online test \ online test \Database1.mdf; +综合安全=真; +database =< test.mdf';;
string source_1 = @Data Source =（LocalDB）\ MSSQLLocalDB; + @AttachDbFilename = C：\Users\NASH\Documents\Visual Studio 2015 \Projects\ ## onon test \ online test \ test.mdf; +Integrated Security = True;
SqlConnection Con_1 =新的SqlConnection（source_1）;
{
Con_1.Open（）;
MessageBox.Show（连接到db）;
String sqlSelectQuery = @SELECT * FROM [Table];
SqlCommand cmd = new SqlCommand（sqlSelectQuery，Con_1）;
SqlDataReader dr = cmd.ExecuteReader（）;
if（dr.Read（））
{
// incre +;
{
label2.Text =（dr [Question]。ToString（））;
textBox1.Text =（dr [sl]。ToString（））;
radioButton1.Text =（dr [Option A]。ToString（））;
radioButton2.Text =（dr [Option B]。ToString（））;
radioButton3.Text =（dr [Option C]。ToString（））;
radioButton4.Text =（dr [Option D]。ToString（））;
}
incre = Convert.ToInt32（textBox1.Text）;
//递增++;
// @SELECT * FROM [Table] WHERE sl =，增量;
}
Con_1.Close（）;
}
}
// button1_click是下一个按钮
private void button1_Click（object sender，EventArgs e）
{
incre ++;
String sqlSelectQuery = @SELECT * FROM [Table] WHERE sl = incre;
if（dr.Read（））
{
// incre +;
{
label2.Text =（dr [Question]。ToString（））;
textBox1.Text =（dr [sl]。ToString（））;
radioButton1.Text =（dr [Option A]。ToString（））;
radioButton2.Text =（dr [Option B]。ToString（））;
radioButton3.Text =（dr [Option C]。ToString（））;
radioButton4.Text =（dr [Option D]。ToString（））;
}
}
// button3_click是上一个按钮
private void button3_Click（object sender，EventArgs e）
{
}
private void button2_Click（object sender，EventArgs e）
{
}
private void textBox1_TextChanged（对象发件人，EventArgs e）
{
}
}
}
解决方案
尝试：
更新 MyTable SET MyColumn = MyColumn + 1 WHERE ...
要更改数据库值，您需要执行更新声明，不选择！
i want to increment the database value with every click of the button.
What I have tried:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace online_test
{
public partial class Form1 : Form
{
int incre = 0;
public Form1()
{
InitializeComponent();
radioButton1.TabStop = false;
radioButton2.TabStop = false;
radioButton3.TabStop = false;
radioButton4.TabStop = false;
//qn1();
}
private void Form1_Load(object sender, EventArgs e)
{
//string source_1 = @"DataSource=(LocalDB)\MSSQLLocalDB;" + @"AttachDbFilename=C: \Users\NASH\Documents\Visual Studio 2015\Projects\C#\online test\online test\Database1.mdf;" + "Integrated Security=True;" + "database=<test.mdf';";
string source_1 = @"Data Source = (LocalDB)\MSSQLLocalDB;" + @"AttachDbFilename=C:\Users\NASH\Documents\Visual Studio 2015\Projects\C#\online test\online test\test.mdf;" + "Integrated Security = True";
SqlConnection Con_1 = new SqlConnection(source_1);
{
Con_1.Open();
MessageBox.Show("connected to db");
String sqlSelectQuery = @"SELECT * FROM[Table]";
SqlCommand cmd = new SqlCommand(sqlSelectQuery, Con_1);
SqlDataReader dr = cmd.ExecuteReader();
if (dr.Read())
{
//incre++;
{
label2.Text = (dr["Question"].ToString());
textBox1.Text = (dr["sl"].ToString());
radioButton1.Text = (dr["Option A"].ToString());
radioButton2.Text = (dr["Option B"].ToString());
radioButton3.Text = (dr["Option C"].ToString());
radioButton4.Text = (dr["Option D"].ToString());
}
incre = Convert.ToInt32(textBox1.Text);
// incre++;
// @"SELECT * FROM[Table]WHERE sl=",incre;
}
Con_1.Close();
}
}
//button1_click is next button
private void button1_Click(object sender, EventArgs e)
{
incre++;
String sqlSelectQuery = @"SELECT * FROM[Table] WHERE sl=incre";
if (dr.Read())
{
//incre++;
{
label2.Text = (dr["Question"].ToString());
textBox1.Text = (dr["sl"].ToString());
radioButton1.Text = (dr["Option A"].ToString());
radioButton2.Text = (dr["Option B"].ToString());
radioButton3.Text = (dr["Option C"].ToString());
radioButton4.Text = (dr["Option D"].ToString());
}
}
// button3_click is previous button
private void button3_Click(object sender, EventArgs e)
{
}
private void button2_Click(object sender, EventArgs e)
{
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
}
}
} 解决方案
Try:
UPDATE MyTable SET MyColumn = MyColumn + 1 WHERE ...
To change the database value(s) you need to perform the UPDATE statement, not SELECT!
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