1.NuGet管理包引用3个文件
NuGet管理包搜索引用System.Data.SQLite 作者:SQLite Development Team,自动引用3个文件
2.DbHelperSQLite帮助类(注意更换namespace demo2)
using System;
using System.Collections;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SQLite;
using System.Linq;
using System.Web;
namespace demo2
{
/// <summary>
/// 数据访问基础类(基于SQLite)
/// 可以用户可以修改满足自己项目的需要。
/// </summary>
public abstract class DbHelperSQLite
{
//数据库连接字符串(web.config来配置),可以动态更改connectionString支持多数据库.
public static string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();
//数据库连接字符串(直连配置)
//public static string connectionString = @"Data Source=|DataDirectory|demo2sqlite.db;Initial Catalog=sqlite;Integrated Security=True;Max Pool Size=10";
public DbHelperSQLite()
{
}
#region 公用方法
public static int GetMaxID(string FieldName, string TableName)
{
string strsql = "select max(" + FieldName + ")+1 from " + TableName;
object obj = GetSingle(strsql);
if (obj == null)
{
return 1;
}
else
{
return int.Parse(obj.ToString());
}
}
public static bool Exists(string strSql)
{
object obj = GetSingle(strSql);
int cmdresult;
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
public static bool Exists(string strSql, params SQLiteParameter[] cmdParms)
{
object obj = GetSingle(strSql, cmdParms);
int cmdresult;
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
cmdresult = 0;
}
else
{
cmdresult = int.Parse(obj.ToString());
}
if (cmdresult == 0)
{
return false;
}
else
{
return true;
}
}
#endregion
#region 执行简单SQL语句
/// <summary>
/// 执行SQL语句,返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
{
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SQLite.SQLiteException E)
{
connection.Close();
throw new Exception(E.Message);
}
}
}
}
/// <summary>
/// 执行多条SQL语句,实现数据库事务。
/// </summary>
/// <param name="SQLStringList">多条SQL语句</param>
public static void ExecuteSqlTran(ArrayList SQLStringList)
{
using (SQLiteConnection conn = new SQLiteConnection(connectionString))
{
conn.Open();
SQLiteCommand cmd = new SQLiteCommand();
cmd.Connection = conn;
SQLiteTransaction tx = conn.BeginTransaction();
cmd.Transaction = tx;
try
{
for (int n = 0; n < SQLStringList.Count; n++)
{
string strsql = SQLStringList[n].ToString();
if (strsql.Trim().Length > 1)
{
cmd.CommandText = strsql;
cmd.ExecuteNonQuery();
}
}
tx.Commit();
}
catch (System.Data.SQLite.SQLiteException E)
{
tx.Rollback();
throw new Exception(E.Message);
}
}
}
/// <summary>
/// 执行带一个存储过程参数的的SQL语句。
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <param name="content">参数内容,比如一个字段是格式复杂的文章,有特殊符号,可以通过这个方式添加</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString, string content)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
SQLiteCommand cmd = new SQLiteCommand(SQLString, connection);
SQLiteParameter myParameter = new SQLiteParameter("@content", DbType.String);
myParameter.Value = content;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SQLite.SQLiteException E)
{
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)
/// </summary>
/// <param name="strSQL">SQL语句</param>
/// <param name="fs">图像字节,数据库的字段类型为image的情况</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSqlInsertImg(string strSQL, byte[] fs)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
SQLiteParameter myParameter = new SQLiteParameter("@fs", DbType.Binary);
myParameter.Value = fs;
cmd.Parameters.Add(myParameter);
try
{
connection.Open();
int rows = cmd.ExecuteNonQuery();
return rows;
}
catch (System.Data.SQLite.SQLiteException E)
{
throw new Exception(E.Message);
}
finally
{
cmd.Dispose();
connection.Close();
}
}
}
/// <summary>
/// 执行一条计算查询结果语句,返回查询结果(object)。
/// </summary>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果(object)</returns>
public static object GetSingle(string SQLString)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
using (SQLiteCommand cmd = new SQLiteCommand(SQLString, connection))
{
try
{
connection.Open();
object obj = cmd.ExecuteScalar();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (System.Data.SQLite.SQLiteException e)
{
connection.Close();
throw new Exception(e.Message);
}
}
}
}
/// <summary>
/// 执行查询语句,返回SQLiteDataReader
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>SQLiteDataReader</returns>
public static SQLiteDataReader ExecuteReader(string strSQL)
{
SQLiteConnection connection = new SQLiteConnection(connectionString);
SQLiteCommand cmd = new SQLiteCommand(strSQL, connection);
try
{
connection.Open();
SQLiteDataReader myReader = cmd.ExecuteReader();
return myReader;
}
catch (System.Data.SQLite.SQLiteException e)
{
throw new Exception(e.Message);
}
}
/// <summary>
/// 执行查询语句,返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
DataSet ds = new DataSet();
try
{
connection.Open();
SQLiteDataAdapter command = new SQLiteDataAdapter(SQLString, connection);
command.Fill(ds, "ds");
}
catch (System.Data.SQLite.SQLiteException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
#endregion
#region 执行带参数的SQL语句
/// <summary>
/// 执行SQL语句,返回影响的记录数
/// </summary>
/// <param name="SQLString">SQL语句</param>
/// <returns>影响的记录数</returns>
public static int ExecuteSql(string SQLString, params SQLiteParameter[] cmdParms)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
using (SQLiteCommand cmd = new SQLiteCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
int rows = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
return rows;
}
catch (System.Data.SQLite.SQLiteException E)
{
throw new Exception(E.Message);
}
}
}
}
/// <summary>
/// 执行多条SQL语句,实现数据库事务。
/// </summary>
/// <param name="SQLStringList">SQL语句的哈希表(key为sql语句,value是该语句的SQLiteParameter[])</param>
public static void ExecuteSqlTran(Hashtable SQLStringList)
{
using (SQLiteConnection conn = new SQLiteConnection(connectionString))
{
conn.Open();
using (SQLiteTransaction trans = conn.BeginTransaction())
{
SQLiteCommand cmd = new SQLiteCommand();
try
{
//循环
foreach (DictionaryEntry myDE in SQLStringList)
{
string cmdText = myDE.Key.ToString();
SQLiteParameter[] cmdParms = (SQLiteParameter[])myDE.Value;
PrepareCommand(cmd, conn, trans, cmdText, cmdParms);
int val = cmd.ExecuteNonQuery();
cmd.Parameters.Clear();
trans.Commit();
}
}
catch
{
trans.Rollback();
throw;
}
}
}
}
/// <summary>
/// 执行一条计算查询结果语句,返回查询结果(object)。
/// </summary>
/// <param name="SQLString">计算查询结果语句</param>
/// <returns>查询结果(object)</returns>
public static object GetSingle(string SQLString, params SQLiteParameter[] cmdParms)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
using (SQLiteCommand cmd = new SQLiteCommand())
{
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
object obj = cmd.ExecuteScalar();
cmd.Parameters.Clear();
if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))
{
return null;
}
else
{
return obj;
}
}
catch (System.Data.SQLite.SQLiteException e)
{
throw new Exception(e.Message);
}
}
}
}
/// <summary>
/// 执行查询语句,返回SQLiteDataReader
/// </summary>
/// <param name="strSQL">查询语句</param>
/// <returns>SQLiteDataReader</returns>
public static SQLiteDataReader ExecuteReader(string SQLString, params SQLiteParameter[] cmdParms)
{
SQLiteConnection connection = new SQLiteConnection(connectionString);
SQLiteCommand cmd = new SQLiteCommand();
try
{
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
SQLiteDataReader myReader = cmd.ExecuteReader();
cmd.Parameters.Clear();
return myReader;
}
catch (System.Data.SQLite.SQLiteException e)
{
throw new Exception(e.Message);
}
}
/// <summary>
/// 执行查询语句,返回DataSet
/// </summary>
/// <param name="SQLString">查询语句</param>
/// <returns>DataSet</returns>
public static DataSet Query(string SQLString, params SQLiteParameter[] cmdParms)
{
using (SQLiteConnection connection = new SQLiteConnection(connectionString))
{
SQLiteCommand cmd = new SQLiteCommand();
PrepareCommand(cmd, connection, null, SQLString, cmdParms);
using (SQLiteDataAdapter da = new SQLiteDataAdapter(cmd))
{
DataSet ds = new DataSet();
try
{
da.Fill(ds, "ds");
cmd.Parameters.Clear();
}
catch (System.Data.SQLite.SQLiteException ex)
{
throw new Exception(ex.Message);
}
return ds;
}
}
}
private static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, SQLiteTransaction trans, string cmdText, SQLiteParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
if (trans != null)
cmd.Transaction = trans;
cmd.CommandType = CommandType.Text;//cmdType;
if (cmdParms != null)
{
foreach (SQLiteParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}
#endregion
}
}
3.Web.config配置连接字符串(SQLite3数据类型,完全本地,无账号密码)!!!默认.db数据库数据文件存储在App_Data文件夹内!!!!!!!!!!!!!!!!
<configuration>
<configSections>
<!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
<section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</configSections>
<!--!!!!!!!!!!!!!!!!!!!-->
<!--添加sqlite连接-->
<connectionStrings>
<add name="ConnectionString" connectionString="Data Source=|DataDirectory|demo2sqlite.db;Pooling=true;FailIfMissing=false" providerName="System.Data.SQLite" />
</connectionStrings>
<!--!!!!!!!!!!!!!!!!!!!-->
<appSettings>
<add key="webpages:Version" value="3.0.0.0" />
<add key="webpages:Enabled" value="false" />
<add key="ClientValidationEnabled" value="true" />
<add key="UnobtrusiveJavaScriptEnabled" value="true" />
</appSettings>
。
。
。
。
。
。
</configuration>
4.操作SQLite数据库软件==》SQLiteStudio
5.SQLite设置主键自动增长及插入语法
SQLite中,一个自增长字段定义为INTEGER PRIMARY KEY AUTOINCREMENT,那么在插入一个新数据时,只需要将这个字段的值指定为NULL,即可由引擎自动设定其值,引擎会设定为最大的rowid+1。如果表為空,那麼將會插入1。
比如,有一張表ID為自增:
CREATE TABLE Product
(
ID INTEGER PRIMARY KEY AUTOINCREMENT,
Name NVARCHAR(100) NOT NULL
)