做网站卖水果哪里进货,做网站前端和平面配合,做多语言网站多少钱,外贸联系网站微软官网资料链接#xff08;可下载文档#xff09;
教程参考链接#xff1a;SQLite 教程 - SQLite中文手册
项目中对应的system.dat文件可以用SQLiteStudio打开查看
参考文档#xff1a;https://d7ehk.jb51.net/202008/books/SQLite_jb51.rar 总结介绍
1、下载SQLiteS…微软官网资料链接可下载文档
教程参考链接SQLite 教程 - SQLite中文手册
项目中对应的system.dat文件可以用SQLiteStudio打开查看
参考文档https://d7ehk.jb51.net/202008/books/SQLite_jb51.rar 总结介绍
1、下载SQLiteStudio对数据库文件进行管理、查看
2、代码中通过NuGet添加System.Data.SQLite
3、代码类SQLiteConnection连接本地数据库文件》SQLiteCommand配置命令并执行》连接关闭
一、SQLite数据下载安装使用管理查看数据
1下载
下载绿色免安装版本
链接百度网盘 请输入提取码
提取码hgoc
1、参考网站SQLite Home Page下载地址System.Data.SQLite: Downloads Page
2安装 免安装双击SQLiteStudio可以打开使用如果放在项目中建议复制到C:\Program Files (x86) 防止被误删除掉
3添加数据库 数据库》添加数据库》输入数据名称》确定
4创建数据表 Tables》新建表 自动生成的创建表的sql语句 1 2 3 4 5 6 7 8 CREATE TABLE SysAdmin ( LoginID INTEGER PRIMARY KEY AUTOINCREMENT DEFAULT (10000), LoginName VARCHAR (20) NOT NULL, LoginPwd VARCHAR (50) NOT NULL, Role INTEGER DEFAULT (0) NOT NULL ); 5添加字段 6数据库的位置 数据表都创建好了之后鼠标放在数据库名上就显示数据库所在的目录 二、C#使用SQLite数据需要添加的引用上面的wiki路径下载里有
1VS使用NuGet添加使用搜索System.Data.SQLite添加即可
三、代码中数据库命令操作
包含功能增删数据库文件增删改数据表增删改查数据内容
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SQLite;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using static System.Windows.Forms.VisualStyles.VisualStyleElement;namespace MyFrom
{public partial class Form1 : Form{public Form1(){InitializeComponent();}// 添加数据表private void button1_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);//cn.Open();cn.Close();label1.Text 添加数据库完成;}// 删除数据表private void button2_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;if (System.IO.File.Exists(path)){System.IO.File.Delete(path);}label1.Text 删除数据库完成;}// 添加数据表private void button3_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;// cmd.CommandText CREATE TABLE t1(time stringid varchar(4),score int);cmd.CommandText CREATE TABLE IF NOT EXISTS t1(time string,id varchar(4),score int);cmd.ExecuteNonQuery();}cn.Close();label1.Text 添加数据表完成;}// 删除数据表private void button4_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;cmd.CommandText DROP TABLE IF EXISTS t1;cmd.ExecuteNonQuery();}cn.Close();label1.Text 删除数据表完成;}// 更改数据表名private void button5_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;cmd.CommandText ALTER TABLE t3 RENAME TO t1;cmd.ExecuteNonQuery();}cn.Close();label1.Text 更改表名完成;}// 添加数据表列元素private void button6_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;cmd.CommandText ALTER TABLE t1 ADD COLUMN age int;cmd.ExecuteNonQuery();}cn.Close();label1.Text 添加列完成;}// 添加数据private void button7_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;//time string,id varchar(4),score intcmd.CommandText INSERT INTO t1(time,id,score) VALUES(time,id,score);cmd.Parameters.Add(id, DbType.String).Value 666;//cmd.Parameters.Add(age, DbType.Int32).Value n;cmd.Parameters.Add(score, DbType.Int32).Value 22;cmd.Parameters.Add(time, DbType.String).Value DateTime.Now.ToString();cmd.ExecuteNonQuery();}cn.Close();label1.Text 添加数据完成;}// 更改数据private void button8_Click(object sender, EventArgs e){string s 888;int n 1077777;int myscore 1;string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;//time string,id varchar(4),score intcmd.CommandText UPDATE t1 SET idid,ageage WHERE id666;cmd.Parameters.Add(id, DbType.String).Value s;cmd.Parameters.Add(age, DbType.Int32).Value n;cmd.ExecuteNonQuery();}cn.Close();label1.Text 更改数据完成;}// 删除数据private void button9_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;//time string,id varchar(4),score intcmd.CommandText DELETE FROM t1 WHERE id888;cmd.ExecuteNonQuery();}cn.Close();label1.Text 删除数据完成;}// 查询数据private void button10_Click(object sender, EventArgs e){string path Application.StartupPath \\test.db;SQLiteConnection cn new SQLiteConnection(data source path);if (cn.State ! System.Data.ConnectionState.Open){cn.Open();SQLiteCommand cmd new SQLiteCommand();cmd.Connection cn;//time string,id varchar(4),score intcmd.CommandText SELECT * FROM t1 WHERE rowid2; // 读取第二行行数从1开始SQLiteDataReader sr cmd.ExecuteReader();Console.WriteLine(查询到的数据如下);while (sr.Read()){int count sr.VisibleFieldCount;for (int i 0; i count; i){Console.WriteLine(sr[i].ToString() );}string s sr.GetString(0);Console.WriteLine(s);}sr.Close();}cn.Close();label1.Text 查询数据完成;}}
}
