一 准備工作
sqlite3.exe 下載地址：http://www.sqlite.org/download.html 下載"sqlite-shell-win32-x86-
3070800.zip" 就OK了Precompiled Binaries For Windows
sqlite-shell-win32-x86-3070800.zip
(248.28 KiB)
system.data.sqlite.dll 下載地址: http://www.dllzj.com/Down_System.Data.SQLite.DLL.html 這個dll
用於Visual Studio 項目中引用
二，試用sqlite3.exe
解壓sqlite-shell-win32-x86-3070800.zip 到F:\jonse\DownLoads\sqlLite 目錄下
開始-->運行-->cmd
>F:
>cd F:\jonse\DownLoads\sqlLite
>sqlite3 myDB.db (如果myDB.db不存在，則創建之；若存在，則打開它)
>create table test(id int,name varchar(20),remark varchar(200)); (創建test表，三列：
id,name,remark)
>insert into test select 1,'name1','remark1' union select 2,'name2','remark2'; (暫時插入2行數據)
>.mode column (顯示列模式)
>.headers on (顯示列頭信息)
>select * from test; (查詢所有的數據)
>select ifnull(max(id),0) as MaxID from test; (查詢test表最大的ID值)
三, C# 使用sqlite
在VS2010的項目引用中添加System.Data.SQLite.dll (這個在准備工作中已經下載好的)
(1),新建一個SqlLiteHelper.cs 的類
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SQLite;
using System.Data.Common;
namespace JonseTest
{
public abstract class SqlLiteHelper
{
public static string ConnSqlLiteDbPath = string.Empty;
public static string ConnString
{
get
{
return string.Format(@"Data Source={0}", ConnSqlLiteDbPath);
}
}
// 取datatable
public static DataTable GetDataTable(out string sError,string sSQL)
{
DataTable dt = null;
sError = string.Empty;
try
{
SQLiteConnection conn = new SQLiteConnection(ConnString);
conn.Open();
SQLiteCommand cmd = new SQLiteCommand();
cmd.CommandText = sSQL;
cmd.Connection = conn;
SQLiteDataAdapter dao = new SQLiteDataAdapter(cmd);
dt = new DataTable();
dao.Fill(dt);
}
catch (Exception ex)
{
sError = ex.Message;
}
return dt;
}
// 取某個單一的元素
public static object GetSingle(out string sError, string sSQL)
{
DataTable dt = GetDataTable(out sError, sSQL);
if (dt != null && dt.Rows.Count > 0)
{
return dt.Rows[0][0];
}
return null;
}
// 取最大的ID
public static Int32 GetMaxID(out string sError, string sKeyField,string sTableName)
{
DataTable dt = GetDataTable(out sError, "select ifnull(max([" + sKeyField + "]),0) as
MaxID from [" + sTableName + "]");
if (dt != null && dt.Rows.Count > 0)
{
return Convert.ToInt32(dt.Rows[0][0].ToString());
}
return 0;
}
// 執行insert,update,delete 動作，也可以使用事務
public static bool UpdateData(out string sError, string sSQL,bool bUseTransaction=false)
{
int iResult = 0;
sError = string.Empty;
if (!bUseTransaction)
{
try
{
SQLiteConnection conn = new SQLiteConnection(ConnString);
conn.Open();
SQLiteCommand comm = new SQLiteCommand(conn);
comm.CommandText = sSQL;
iResult = comm.ExecuteNonQuery();
}
catch (Exception ex)
{
sError = ex.Message;
iResult = -1;
}
}
else // 使用事務
{
DbTransaction trans =null;
try
{
SQLiteConnection conn = new SQLiteConnection(ConnString);
conn.Open();
trans = conn.BeginTransaction();
SQLiteCommand comm = new SQLiteCommand(conn);
comm.CommandText = sSQL;
iResult = comm.ExecuteNonQuery();
trans.Commit();
}
catch (Exception ex)
{
sError = ex.Message;
iResult = -1;
trans.Rollback();
}
}
return iResult >0;
}
}
}
(2) 新建一個frmSqlLite 的form
public partial class frmSqlLite : Form
{
string sError = string.Empty;
public frmSqlLite()
{
InitializeComponent();
}
private void InitGrid()
{
SqlLiteHelper.ConnSqlLiteDbPath = @"F:\jonse\DownLoads\sqlLite\myDB.db";
sError = string.Empty;
string sSql = "select * from test";
DataTable dt = SqlLiteHelper.GetDataTable(out sError, sSql);
if (!string.IsNullOrEmpty(sError))
Common.DisplayMsg(this.Text, sError);
dataGridView1.DataSource = dt;
}
private void frmSqlLite_Load(object sender, EventArgs e)
{
InitGrid();
}
private void button1_Click(object sender, EventArgs e)
{
sError=string.Empty;
int iMaxID = SqlLiteHelper.GetMaxID(out sError, "id", "test") + 1;
string sSql = "insert into test select " + iMaxID + ",'name" + iMaxID + "','remark" +
iMaxID + "'";
sError=string.Empty;
bool bResult = SqlLiteHelper.UpdateData(out sError, sSql,true);
if (bResult)
Common.DisplayMsg(this.Text, "插入成功");
InitGrid();
}
private void button2_Click(object sender, EventArgs e)
{
sError = string.Empty;
int iMaxID = SqlLiteHelper.GetMaxID(out sError, "id", "test");
string sSql = "update test set name='name_jonse',remark='remark_jonse' where id=" +
iMaxID;
sError = string.Empty;
bool bResult = SqlLiteHelper.UpdateData(out sError, sSql, true);
if (bResult)
Common.DisplayMsg(this.Text, "修改成功");
InitGrid();
}
private void button3_Click(object sender, EventArgs e)
{
sError = string.Empty;
int iMaxID = SqlLiteHelper.GetMaxID(out sError, "id", "test");
string sSql = "delete from test where id=" + iMaxID;
sError = string.Empty;
bool bResult = SqlLiteHelper.UpdateData(out sError, sSql, true);
if (bResult)
Common.DisplayMsg(this.Text, "刪除成功");
InitGrid();
}
}
(3). 公共類
public abstract class Common
{
public static void DisplayMsg(string sCaption, string sMsg)
{
sMsg = sMsg.TrimEnd('!').TrimEnd('！') + " !";
MessageBox.Show(sMsg, sCaption);
}
public static bool IsNullOrEmptyObject(object oSource)
{
if (oSource != null)
{
return string.IsNullOrEmpty(oSource.ToString());
}
return true;
}
}
摘自 keenweiwei的專欄
