sqlhelper 数据库帮助操作类

数据库帮助类

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using System.Data.SQLite;
 using System.Data;

 namespace SqliteDemo
 {
     /// <summary>
     /// SQLite 操作类
     /// </summary>
     class SqLiteHelper
     {

         /// <summary>
         /// 数据库连接定义
         /// </summary>
         private SQLiteConnection dbConnection;

         /// <summary>
         /// SQL命令定义
         /// </summary>
         private SQLiteCommand dbCommand;

         /// <summary>
         /// 数据读取定义
         /// </summary>
         private SQLiteDataReader dataReader;

         /// <summary>
         /// 数据读取
         /// </summary>
         private SQLiteDataAdapter dataAdapter;

         /// <summary>
         /// 构造函数
         /// </summary>
         /// <param name="connectionString">连接SQLite库字符串</param>
         public SqLiteHelper(string connectionString)
         {
             try
             {
                 dbConnection = new SQLiteConnection(connectionString);
                 dbConnection.Open();
             }
             catch (Exception e)
             {
                 Log(e.ToString());
             }
         }
         /// <summary>
         /// 执行SQL命令
         /// </summary>
         /// <returns>The query.</returns>
         /// <param name="queryString">SQL命令字符串</param>
         public SQLiteDataReader ExecuteQuery(string queryString)
         {
             try
             {
                 dbCommand = dbConnection.CreateCommand();
                 dbCommand.CommandText = queryString;
                 dataReader = dbCommand.ExecuteReader();
             }
             catch (Exception e)
             {
                 Log(e.Message);
             }

             return dataReader;
         }

     public DataTable GetDataTable(string tableName)
         {
             string queryString = "SELECT * FROM " + tableName;
             DataTable dt = new DataTable();
             try
             {
                 dbCommand = dbConnection.CreateCommand();
                 dbCommand.CommandText = queryString;
                 SQLiteDataAdapter ad = new SQLiteDataAdapter(dbCommand);
                 ad.Fill(dt);
             }
             catch (Exception e)
             {
                 Log(e.Message);
             }
             return dt;
         }

         /// <summary>
         /// 关闭数据库连接
         /// </summary>
         public void CloseConnection()
         {
             //销毁Commend
             if (dbCommand != null)
             {
                 dbCommand.Cancel();
             }
             dbCommand = null;
             //销毁Reader
             if (dataReader != null)
             {
                 dataReader.Close();
             }
             dataReader = null;
             //销毁Connection
             if (dbConnection != null)
             {
                 dbConnection.Close();
             }
             dbConnection = null;

         }

         /// <summary>
         /// 读取整张数据表
         /// </summary>
         /// <returns>The full table.</returns>
         /// <param name="tableName">数据表名称</param>
         public SQLiteDataReader ReadFullTable(string tableName)
         {
             string queryString = "SELECT * FROM " + tableName;
             return ExecuteQuery(queryString);
         }

         /// <summary>
         /// 向指定数据表中插入数据
         /// </summary>
         /// <returns>The values.</returns>
         /// <param name="tableName">数据表名称</param>
         /// <param name="values">插入的数值</param>
         public SQLiteDataReader InsertValues(string tableName, string[] values)
         {
             //获取数据表中字段数目
             int fieldCount = ReadFullTable(tableName).FieldCount;
             //当插入的数据长度不等于字段数目时引发异常
             if (values.Length != fieldCount)
             {
                 throw new SQLiteException("values.Length!=fieldCount");
             }

             string queryString = "INSERT INTO " + tableName + " VALUES (" + "'" + values[] + "'";
             for (int i = ; i < values.Length; i++)
             {
                 queryString += ", " + "'" + values[i] + "'";
             }
             queryString += " )";
             return ExecuteQuery(queryString);
         }

         /// <summary>
         /// 更新指定数据表内的数据
         /// </summary>
         /// <returns>The values.</returns>
         /// <param name="tableName">数据表名称</param>
         /// <param name="colNames">字段名</param>
         /// <param name="colValues">字段名对应的数据</param>
         /// <param name="key">关键字</param>
         /// <param name="value">关键字对应的值</param>
         /// <param name="operation">运算符：=,<,>,...，默认“=”</param>
         public SQLiteDataReader UpdateValues(string tableName, string[] colNames, string[] colValues, string key, string value, string operation = "=")
         {
             //当字段名称和字段数值不对应时引发异常
             if (colNames.Length != colValues.Length)
             {
                 throw new SQLiteException("colNames.Length!=colValues.Length");
             }

             string queryString = "UPDATE " + tableName + " SET " + colNames[] + "=" + "'" + colValues[] + "'";
             for (int i = ; i < colValues.Length; i++)
             {
                 queryString += ", " + colNames[i] + "=" + "'" + colValues[i] + "'";
             }
             queryString += " WHERE " + key + operation + "'" + value + "'";
             return ExecuteQuery(queryString);
         }

         /// <summary>
         /// 删除指定数据表内的数据
         /// </summary>
         /// <returns>The values.</returns>
         /// <param name="tableName">数据表名称</param>
         /// <param name="colNames">字段名</param>
         /// <param name="colValues">字段名对应的数据</param>
         public SQLiteDataReader DeleteValuesOR(string tableName, string[] colNames, string[] colValues, string[] operations)
         {
             //当字段名称和字段数值不对应时引发异常
             if (colNames.Length != colValues.Length || operations.Length != colNames.Length || operations.Length != colValues.Length)
             {
                 throw new SQLiteException("colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length");
             }

             string queryString = "DELETE FROM " + tableName + " WHERE " + colNames[] + operations[] + "'" + colValues[] + "'";
             for (int i = ; i < colValues.Length; i++)
             {
                 queryString += "OR " + colNames[i] + operations[] + "'" + colValues[i] + "'";
             }
             return ExecuteQuery(queryString);
         }

         /// <summary>
         /// 删除指定数据表内的数据
         /// </summary>
         /// <returns>The values.</returns>
         /// <param name="tableName">数据表名称</param>
         /// <param name="colNames">字段名</param>
         /// <param name="colValues">字段名对应的数据</param>
         public SQLiteDataReader DeleteValuesAND(string tableName, string[] colNames, string[] colValues, string[] operations)
         {
             //当字段名称和字段数值不对应时引发异常
             if (colNames.Length != colValues.Length || operations.Length != colNames.Length || operations.Length != colValues.Length)
             {
                 throw new SQLiteException("colNames.Length!=colValues.Length || operations.Length!=colNames.Length || operations.Length!=colValues.Length");
             }

             string queryString = "DELETE FROM " + tableName + " WHERE " + colNames[] + operations[] + "'" + colValues[] + "'";
             for (int i = ; i < colValues.Length; i++)
             {
                 queryString += " AND " + colNames[i] + operations[i] + "'" + colValues[i] + "'";
             }
             return ExecuteQuery(queryString);
         }

         /// <summary>
         /// 创建数据表
         /// </summary> +
         /// <returns>The table.</returns>
         /// <param name="tableName">数据表名</param>
         /// <param name="colNames">字段名</param>
         /// <param name="colTypes">字段名类型</param>
         public SQLiteDataReader CreateTable(string tableName, string[] colNames, string[] colTypes)
         {
             string queryString = "CREATE TABLE IF NOT EXISTS " + tableName + "( " + colNames[] + " " + colTypes[];
             for (int i = ; i < colNames.Length; i++)
             {
                 queryString += ", " + colNames[i] + " " + colTypes[i];
             }
             queryString += "  ) ";
             return ExecuteQuery(queryString);
         }

         /// <summary>
         /// Reads the table.
         /// </summary>
         /// <returns>The table.</returns>
         /// <param name="tableName">Table name.</param>
         /// <param name="items">Items.</param>
         /// <param name="colNames">Col names.</param>
         /// <param name="operations">Operations.</param>
         /// <param name="colValues">Col values.</param>
         public SQLiteDataReader ReadTable(string tableName, string[] items, string[] colNames, string[] operations, string[] colValues)
         {
             string queryString = "SELECT " + items[];
             for (int i = ; i < items.Length; i++)
             {
                 queryString += ", " + items[i];
             }
             queryString += " FROM " + tableName + " WHERE " + colNames[] + " " + operations[] + " " + colValues[];
             for (int i = ; i < colNames.Length; i++)
             {
                 queryString += " AND " + colNames[i] + " " + operations[i] + " " + colValues[] + " ";
             }
             return ExecuteQuery(queryString);
         }

         /// <summary>
         /// 本类log
         /// </summary>
         /// <param name="s"></param>
         static void Log(string s)
         {
             Console.WriteLine("class SqLiteHelper:::" + s);
         }
     }
 }

控制台调用

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;

 namespace ConsoleApplication3
 {
     class Program
     {
         private static SqLiteHelper sql;
         static void Main(string[] args)
         {
             sql = new SqLiteHelper(@"data source=E:\620000S00000_20160707\Data.db");

             //读取整张表
             SQLiteDataReader reader = sql.ReadFullTable("SYS_Statistics");

             while (reader.Read())
             {
                 //读取表名
                 string tableName = reader.GetString(reader.GetOrdinal("TableName"));
                 //读取表的数据
                 int Rowcount = reader.GetInt32(reader.GetOrdinal("DataStatistics"));
                 Console.WriteLine(tableName+Rowcount);
             }

             Console.Read();
         }
     }
 }