1、对SQLite的封装：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SQLite;
namespace DataBaseHelper
{
public class SQLiteHelper
{
SQLiteConnection connection = null;
SQLiteTransaction transaction = null;
string conn_str = "";
//----创建连接串并连接数据库----
public SQLiteHelper(string path, string password)
{
conn_str = "data source=" + path + ";password=" + password;
}
public bool Connect()
{
try
{
if (connection != null)
{
connection.Close();
connection = null;
}
connection = new SQLiteConnection(conn_str);
connection.Open();
if (connection == null)
{
return false;
}
return true;
}
catch (SQLiteException ex)
{
return false;
}
}
//----修改数据库密码----
public bool ChangePassword(string newPassword)
{
try
{
connection.ChangePassword(newPassword);
return true;
}
catch (SQLiteException ex)
{
return false;
}
}
//----关闭数据库连接----
public bool DisConnect()
{
try
{
if (connection != null)
{
connection.Close();
connection = null;
}
return true;
}
catch (SQLiteException ex)
{
return false;
}
}
/// <summary>
/// 执行一个查询语句，返回一个包含查询结果的DataTable
/// </summary>
/// <param name="sql">要执行的查询语句</param>
/// <param name="parameters">执行SQL查询语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
/// <returns></returns>
public DataTable ExecuteDataTable(string sql, SQLiteParameter[] parameters)
{
try
{
using (SQLiteCommand Command = new SQLiteCommand(sql, connection))
{
if (parameters != null)
{
Command.Parameters.AddRange(parameters);
}
SQLiteDataAdapter adapter = new SQLiteDataAdapter(Command);
DataTable dataTable = new DataTable();
adapter.Fill(dataTable);
return dataTable;
}
}
catch (SQLiteException ex)
{
return null;
}
}
/// <summary>
/// 对SQLite数据库执行增删改操作，返回受影响的行数。
/// </summary>
/// <param name="sql">要执行的增删改的SQL语句</param>
/// <param name="parameters">执行增删改语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql, SQLiteParameter[] parameters)
{
int affectRows = 0;
try
{
using (SQLiteTransaction Transaction = connection.BeginTransaction())
{
using (SQLiteCommand Command = new SQLiteCommand(sql, connection, Transaction))
{
if (parameters != null)
{
Command.Parameters.AddRange(parameters);
}
affectRows = Command.ExecuteNonQuery();
}
Transaction.Commit();
}
}
catch (SQLiteException ex)
{
affectRows = -1;
}
return affectRows;
}
//收缩数据库 VACUUM
public bool Vacuum()
{
try
{
using (SQLiteCommand Command = new SQLiteCommand("VACUUM", connection))
{
Command.ExecuteNonQuery();
}
return true;
}
catch (System.Data.SQLite.SQLiteException ex)
{
return false;
}
}
public void BeginTransaction()
{
try
{
transaction = connection.BeginTransaction();
}
catch (SQLiteException ex)
{
}
}
public void CommitTransaction()
{
try
{
transaction.Commit();
}
catch (SQLiteException ex)
{
}
}
public void RollbackTransaction()
{
try
{
transaction.Rollback();
}
catch (SQLiteException ex)
{
}
}
public void test()
{
SQLiteHelper helper = new SQLiteHelper("D:\\mysqlite.db","123456"); //连接到D盘下的mysqlite.db数据库,连接密码为123456
//bool ch = helper.ChangePassword("654321"); //将密码修改为：654321
helper.Connect();
string select_sql = "select * from student"; //查询的SQL语句
DataTable dt = helper.ExecuteDataTable(select_sql, null); //执行查询操作,结果存放在dt中
//向数据库中student表中插入了一条(name = "马兆瑞"，sex = "男"，telephone = "15550000000")的记录
string insert_sql = "insert into student(name,sex,telephone) values(?,?,?)"; //插入的SQL语句(带参数)
SQLiteParameter[] para = new SQLiteParameter[3]; //构造并绑定参数
string[] tag = { "name", "sex", "telephone" };
string[] value = { "马兆瑞","男","15550000000"};
for (int i = 0; i < 3; i++)
{
para[i] = new SQLiteParameter(tag[i], value[i]);
}
int ret = helper.ExecuteNonQuery(insert_sql, para); //执行插入操作
}
}
}
2、对Access的封装：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.OleDb;
namespace DataBaseHelper
{
public class AccessHelper
{
OleDbConnection connection = null;
OleDbTransaction transaction = null;
string conn_str = "";
//----创建连接串并连接数据库----
public AccessHelper(string path, string password)
{
conn_str = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";Jet OLEDB:Database Password= " + password;
}
public bool Connect()
{
try
{
if (connection != null)
{
connection.Close();
connection = null;
}
connection = new OleDbConnection(conn_str);
connection.Open();
if (connection == null)
{
return false;
}
return true;
}
catch (OleDbException ex)
{
return false;
}
}
////----修改数据库密码----
//public bool ChangePassword(string newPassword)
//{
// try
// {
// connection.ChangePassword(newPassword);
// return true;
// }
// catch (OleDbException ex)
// {
// return false;
// }
//}
//----关闭数据库连接----
public bool DisConnect()
{
try
{
if (connection != null)
{
connection.Close();
connection = null;
}
return true;
}
catch (OleDbException ex)
{
return false;
}
}
/// <summary>
/// 执行一个查询语句，返回一个包含查询结果的DataTable
/// </summary>
/// <param name="sql">要执行的查询语句</param>
/// <param name="parameters">执行SQL查询语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
/// <returns></returns>
public DataTable ExecuteDataTable(string sql, OleDbParameter[] parameters)
{
try
{
using (OleDbCommand Command = new OleDbCommand(sql, connection))
{
if (parameters != null)
{
Command.Parameters.AddRange(parameters);
}
OleDbDataAdapter adapter = new OleDbDataAdapter(Command);
DataTable dataTable = new DataTable();
adapter.Fill(dataTable);
return dataTable;
}
}
catch (OleDbException ex)
{
return null;
}
}
/// <summary>
/// 对Access数据库执行增删改操作，返回受影响的行数。
/// </summary>
/// <param name="sql">要执行的增删改的SQL语句</param>
/// <param name="parameters">执行增删改语句所需要的参数，参数必须以它们在SQL语句中的顺序为准</param>
/// <returns></returns>
public int ExecuteNonQuery(string sql, OleDbParameter[] parameters)
{
int affectRows = 0;
try
{
using (OleDbTransaction Transaction = connection.BeginTransaction())
{
using (OleDbCommand Command = new OleDbCommand(sql, connection, Transaction))
{
if (parameters != null)
{
Command.Parameters.AddRange(parameters);
}
affectRows = Command.ExecuteNonQuery();
}
Transaction.Commit();
}
}
catch (OleDbException ex)
{
affectRows = -1;
}
return affectRows;
}
//收缩数据库 VACUUM
public bool Vacuum()
{
try
{
using (OleDbCommand Command = new OleDbCommand("VACUUM", connection))
{
Command.ExecuteNonQuery();
}
return true;
}
catch (OleDbException ex)
{
return false;
}
}
public void BeginTransaction()
{
try
{
transaction = connection.BeginTransaction();
}
catch (OleDbException ex)
{
}
}
public void CommitTransaction()
{
try
{
transaction.Commit();
}
catch (OleDbException ex)
{
}
}
public void RollbackTransaction()
{
try
{
transaction.Rollback();
}
catch (OleDbException ex)
{
}
}
}
}
调用示例：
AccessHelper helper = new AccessHelper("D:\\myaccess.mdb","123456789"); //连接到D盘下的myaccess.mdb数据库,密码为123456789
helper.Connect();string select_sql = "select * from student"; //查询的SQL语句
DataTable dt = helper.ExecuteDataTable(select_sql, null); //执行查询操作,结果存放在dt中
//向数据库中student表中插入了一条(name = "马兆瑞"，sex = "男"，telephone = "15550000000")的记录
string insert_sql = "insert into student(name,sex,telephone) values(?,?,?)"; //插入的SQL语句(带参数)
OleDbParameter[] para = new OleDbParameter[3]; //构造并绑定参数
string[] tag = { "name", "sex", "telephone" };
string[] value = { "马兆瑞","男","15550000000"};
for (int i = 0; i < 3; i++)
{
para[i] = new OleDbParameter(tag[i], value[i]);
}
int ret = helper.ExecuteNonQuery(insert_sql, para); //执行插入操作
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