Sous le nœud du fichier de configuration client
<connectionStrings> <add name="localdb" connectionString="Data Source=config/local.db;Version=3;UseUTF16Encoding=True;" providerName="System.Data.SQLite.SQLiteFactory"/> </connectionStrings>
où [localdb] est le local Le nom de la base de données SQLite, [config/local.db] est l'emplacement de la base de données SQLite dans le répertoire d'exécution du programme actuel
Encapsulation d'accès à la base de données C# SQLite code de classe :
/// <summary>
/// 本类为SQLite数据库帮助静态类,使用时只需直接调用即可,无需实例化
/// </summary>
public static class SQLiteHelper
{
// Application.StartupPath
public static string LocalDbConnectionString = ConfigurationManager.ConnectionStrings["localdb"].ConnectionString;
#region ExecuteNonQuery
/// <summary>
/// 执行数据库操作(新增、更新或删除)
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="cmd">SqlCommand对象</param>
/// <returns>所受影响的行数</returns>
public static int ExecuteNonQuery(string connectionString, SQLiteCommand cmd)
{
int result = 0;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
using (SQLiteConnection con = new SQLiteConnection(connectionString))
{
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, true, cmd.CommandType, cmd.CommandText);
try
{
result = cmd.ExecuteNonQuery();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
}
return result;
}
/// <summary>
/// 执行数据库操作(新增、更新或删除)
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <returns>所受影响的行数</returns>
public static int ExecuteNonQuery(string connectionString, string commandText, CommandType commandType)
{
int result = 0;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
SQLiteCommand cmd = new SQLiteCommand();
using (SQLiteConnection con = new SQLiteConnection(connectionString))
{
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, true, commandType, commandText);
try
{
result = cmd.ExecuteNonQuery();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
}
return result;
}
/// <summary>
/// 执行数据库操作(新增、更新或删除)
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <param name="cmdParms">SQL参数对象</param>
/// <returns>所受影响的行数</returns>
public static int ExecuteNonQuery(string connectionString, string commandText, CommandType commandType, params SQLiteParameter[] cmdParms)
{
int result = 0;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
SQLiteCommand cmd = new SQLiteCommand();
using (SQLiteConnection con = new SQLiteConnection(connectionString))
{
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, true, commandType, commandText);
try
{
result = cmd.ExecuteNonQuery();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
}
return result;
}
#endregion
#region ExecuteScalar
/// <summary>
/// 执行数据库操作(新增、更新或删除)同时返回执行后查询所得的第1行第1列数据
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="cmd">SqlCommand对象</param>
/// <returns>查询所得的第1行第1列数据</returns>
public static object ExecuteScalar(string connectionString, SQLiteCommand cmd)
{
object result = 0;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
using (SQLiteConnection con = new SQLiteConnection(connectionString))
{
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, true, cmd.CommandType, cmd.CommandText);
try
{
result = cmd.ExecuteScalar();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
}
return result;
}
/// <summary>
/// 执行数据库操作(新增、更新或删除)同时返回执行后查询所得的第1行第1列数据
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <returns>查询所得的第1行第1列数据</returns>
public static object ExecuteScalar(string connectionString, string commandText, CommandType commandType)
{
object result = 0;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
SQLiteCommand cmd = new SQLiteCommand();
using (SQLiteConnection con = new SQLiteConnection(connectionString))
{
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, true, commandType, commandText);
try
{
result = cmd.ExecuteScalar();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
}
return result;
}
/// <summary>
/// 执行数据库操作(新增、更新或删除)同时返回执行后查询所得的第1行第1列数据
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <param name="cmdParms">SQL参数对象</param>
/// <returns>查询所得的第1行第1列数据</returns>
public static object ExecuteScalar(string connectionString, string commandText, CommandType commandType, params SQLiteParameter[] cmdParms)
{
object result = 0;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
SQLiteCommand cmd = new SQLiteCommand();
using (SQLiteConnection con = new SQLiteConnection(connectionString))
{
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, true, commandType, commandText);
try
{
result = cmd.ExecuteScalar();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
}
return result;
}
#endregion
#region ExecuteReader
/// <summary>
/// 执行数据库查询，返回SqlDataReader对象
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="cmd">SqlCommand对象</param>
/// <returns>SqlDataReader对象</returns>
public static DbDataReader ExecuteReader(string connectionString, SQLiteCommand cmd)
{
DbDataReader reader = null;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
SQLiteConnection con = new SQLiteConnection(connectionString);
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, false, cmd.CommandType, cmd.CommandText);
try
{
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception ex)
{
throw ex;
}
return reader;
}
/// <summary>
/// 执行数据库查询，返回SqlDataReader对象
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <returns>SqlDataReader对象</returns>
public static DbDataReader ExecuteReader(string connectionString, string commandText, CommandType commandType)
{
DbDataReader reader = null;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
SQLiteConnection con = new SQLiteConnection(connectionString);
SQLiteCommand cmd = new SQLiteCommand();
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, false, commandType, commandText);
try
{
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception ex)
{
throw ex;
}
return reader;
}
/// <summary>
/// 执行数据库查询，返回SqlDataReader对象
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <param name="cmdParms">SQL参数对象</param>
/// <returns>SqlDataReader对象</returns>
public static DbDataReader ExecuteReader(string connectionString, string commandText, CommandType commandType, params SQLiteParameter[] cmdParms)
{
DbDataReader reader = null;
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
SQLiteConnection con = new SQLiteConnection(connectionString);
SQLiteCommand cmd = new SQLiteCommand();
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, false, commandType, commandText, cmdParms);
try
{
reader = cmd.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception ex)
{
throw ex;
}
return reader;
}
#endregion
#region ExecuteDataSet
/// <summary>
/// 执行数据库查询，返回DataSet对象
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="cmd">SqlCommand对象</param>
/// <returns>DataSet对象</returns>
public static DataSet ExecuteDataSet(string connectionString, SQLiteCommand cmd)
{
DataSet ds = new DataSet();
SQLiteConnection con = new SQLiteConnection(connectionString);
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, false, cmd.CommandType, cmd.CommandText);
try
{
SQLiteDataAdapter sda = new SQLiteDataAdapter(cmd);
sda.Fill(ds);
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (cmd.Connection != null)
{
if (cmd.Connection.State == ConnectionState.Open)
{
cmd.Connection.Close();
}
}
}
return ds;
}
/// <summary>
/// 执行数据库查询，返回DataSet对象
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <returns>DataSet对象</returns>
public static DataSet ExecuteDataSet(string connectionString, string commandText, CommandType commandType)
{
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
DataSet ds = new DataSet();
SQLiteConnection con = new SQLiteConnection(connectionString);
SQLiteCommand cmd = new SQLiteCommand();
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, false, commandType, commandText);
try
{
SQLiteDataAdapter sda = new SQLiteDataAdapter(cmd);
sda.Fill(ds);
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (con != null)
{
if (con.State == ConnectionState.Open)
{
con.Close();
}
}
}
return ds;
}
/// <summary>
/// 执行数据库查询，返回DataSet对象
/// </summary>
/// <param name="connectionString">连接字符串</param>
/// <param name="commandText">执行语句或存储过程名</param>
/// <param name="commandType">执行类型</param>
/// <param name="cmdParms">SQL参数对象</param>
/// <returns>DataSet对象</returns>
public static DataSet ExecuteDataSet(string connectionString, string commandText, CommandType commandType, params SQLiteParameter[] cmdParms)
{
if (connectionString == null || connectionString.Length == 0)
throw new ArgumentNullException("connectionString");
if (commandText == null || commandText.Length == 0)
throw new ArgumentNullException("commandText");
DataSet ds = new DataSet();
SQLiteConnection con = new SQLiteConnection(connectionString);
SQLiteCommand cmd = new SQLiteCommand();
SQLiteTransaction trans = null;
PrepareCommand(cmd, con, ref trans, false, commandType, commandText, cmdParms);
try
{
SQLiteDataAdapter sda = new SQLiteDataAdapter(cmd);
sda.Fill(ds);
}
catch (Exception ex)
{
throw ex;
}
finally
{
if (con != null)
{
if (con.State == ConnectionState.Open)
{
con.Close();
}
}
}
return ds;
}
#endregion
#region 通用分页查询方法
/// <summary>
/// 通用分页查询方法
/// </summary>
/// <param name="connString">连接字符串</param>
/// <param name="tableName">表名</param>
/// <param name="strColumns">查询字段名</param>
/// <param name="strWhere">where条件</param>
/// <param name="strOrder">排序条件</param>
/// <param name="pageSize">每页数据数量</param>
/// <param name="currentIndex">当前页数</param>
/// <param name="recordOut">数据总量</param>
/// <returns>DataTable数据表</returns>
public static DataTable SelectPaging(string connString, string tableName, string strColumns, string strWhere, string strOrder, int pageSize, int currentIndex, out int recordOut)
{
DataTable dt = new DataTable();
recordOut = Convert.ToInt32(ExecuteScalar(connString, "select count(*) from " + tableName, CommandType.Text));
string pagingTemplate = "select {0} from {1} where {2} order by {3} limit {4} offset {5} ";
int offsetCount = (currentIndex - 1) * pageSize;
string commandText = String.Format(pagingTemplate, strColumns, tableName, strWhere, strOrder, pageSize.ToString(), offsetCount.ToString());
using (DbDataReader reader = ExecuteReader(connString, commandText, CommandType.Text))
{
if (reader != null)
{
dt.Load(reader);
}
}
return dt;
}
#endregion
#region 预处理Command对象,数据库链接,事务,需要执行的对象,参数等的初始化
/// <summary>
/// 预处理Command对象,数据库链接,事务,需要执行的对象,参数等的初始化
/// </summary>
/// <param name="cmd">Command对象</param>
/// <param name="conn">Connection对象</param>
/// <param name="trans">Transcation对象</param>
/// <param name="useTrans">是否使用事务</param>
/// <param name="cmdType">SQL字符串执行类型</param>
/// <param name="cmdText">SQL Text</param>
/// <param name="cmdParms">SQLiteParameters to use in the command</param>
private static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, ref SQLiteTransaction trans, bool useTrans, CommandType cmdType, string cmdText, params SQLiteParameter[] cmdParms)
{
if (conn.State != ConnectionState.Open)
conn.Open();
cmd.Connection = conn;
cmd.CommandText = cmdText;
if (useTrans)
{
trans = conn.BeginTransaction(IsolationLevel.ReadCommitted);
cmd.Transaction = trans;
}
cmd.CommandType = cmdType;
if (cmdParms != null)
{
foreach (SQLiteParameter parm in cmdParms)
cmd.Parameters.Add(parm);
}
}
#endregion
}Utiliser la démo :
/// <summary>
/// 获取数据库关键字信息
/// </summary>
/// <param name="category">分类</param>
/// <param name="versions">版本</param>
/// <returns></returns>
private DataSet GetSystemDataBaseKeyWords(string category, string versions)
{
StringBuilder sql = new StringBuilder();
sql.Append("SELECT Keywords , Versions , Type , Description , Category , Id , Extends ");
sql.Append(" FROM A_DataBaseKeyWords ");
sql.AppendFormat(" WHERE 1={0} ", "1");
if (!String.IsNullOrEmpty(category))
{
sql.AppendFormat(" AND Category='{0}'", category);
}
if (!String.IsNullOrEmpty(versions))
{
sql.AppendFormat(" AND Versions='{0}'", versions);
}
return SQLiteHelper.ExecuteDataSet(SQLiteHelper.LocalDbConnectionString, sql.ToString(), CommandType.Text);
}Ce qui précède est le contenu de la classe d'encapsulation d'accès à la base de données C# SQLite. Pour plus de contenu connexe, veuillez faire attention au site Web PHP chinois (www.php.cn) !
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