网上有许多介绍关于SQLite数据库的，这里我就不多说了，这里主要介绍SQLite数据库在C#中的应用，它的应用主要依赖于System.Data.SQLite.dll文件，可以点击这里下载https://pan.baidu.com/s/1dYVM53qiZAFbQkW6Re69ag。下载完成后直接引用到自己的工程里即可。好了废话不多说，直接上代码。
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Data.SQLite; using System.IO; namespace InspectionQueue.CommonHelper { public class SqliteHelper { private static SqliteHelper _instance; public static SqliteHelper GetInstance() { if(null == _instance) { _instance = new SqliteHelper(); } return _instance; } /// <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; private SqliteHelper() { } public bool CreateDb(string dbPath) { try { if(!File.Exists(dbPath)) { //如果数据库文件不存在,则创建 SQLiteConnection.CreateFile(dbPath); } string conDbPath = "Data Source=" + dbPath; dbConnection = new SQLiteConnection(conDbPath); if(null == dbConnection) { return false; } dbConnection.Open(); } catch(Exception e) { throw e; } return true; } /// <summary> /// 执行SQL命令 /// </summary> /// <param name="queryString"></param> /// <returns></returns> public SQLiteDataReader ExecuteQuery(string queryString) { try { dbCommand = dbConnection.CreateCommand(); dbCommand.CommandText = queryString; dataReader = dbCommand.ExecuteReader(); } catch(Exception e) { throw e; } return dataReader; } /// <summary> /// 关闭数据库连接 /// </summary> public void CloseConncetion() { //销毁Command if(dbCommand != null) { dbCommand.Cancel(); } dbCommand = null; //销毁Reader if(dataReader != null) { dataReader.Close(); } dataReader = null; //销毁Connection if(dbConnection != null) { dbConnection.Clone(); } dbConnection = null; } /// <summary> /// 读取整张数据表 /// </summary> /// <param name="tableName"></param> /// <returns></returns> private 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> /// <param name="tableName"></param> /// <param name="valus"></param> /// <returns></returns> public SQLiteDataReader InsertValue(string tableName, string[] valus) { //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据时引异常 if(valus.Length != fieldCount) { throw new SQLiteException("values.Length != fileCount"); } string queryString = "INSERT INTO" + " " + tableName + " " + "VALUES(" + "'" + valus[0] + "'"; for (int i = 1; i < valus.Length; i++) { queryString += "," + "'" + valus[i] + "'"; } queryString += ")"; return ExecuteQuery(queryString); } /// <summary> /// 更新指定数据表内的数据 /// </summary> /// <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:=,<,></param> /// <returns></returns> public SQLiteDataReader UpdateValues(string tableName, string[] colNames, string[] colValues, string key, string value, string operation) { //operation="=";//默认 //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[0] + "=" + "'" + colValues[0] + "'"; for (int i = 1; i < colValues.Length; i++) { queryString += "," + colNames[i] + "=" + "'" + colValues[i] + "'"; } queryString += "WHERE" + " " + key + operation + "'" + value + "'"; return ExecuteQuery(queryString); } /// <summary> /// 更新指定数据表中的数据 /// </summary> /// <param name="tableName"></param> /// <param name="colNames"></param> /// <param name="colValues"></param> /// <param name="key1"></param> /// <param name="value1"></param> /// <param name="operation"></param> /// <param name="key2"></param> /// <param name="value2"></param> /// <returns></returns> public SQLiteDataReader UpdateValues(string tableName, string[] colNames, string[] colValues,string key1, string value1, string operation, string key2, string value2) { //operation="=";默认 //当字段名称和字段数值不对应时发生异常 if(colNames.Length != colValues.Length) { throw new SQLiteException("colNames.Length != colValues.Length"); } string queryString = "UPDATE" + " " + tableName + " " + "SET" + colNames[0] + "=" + "'" + colValues[0] + "'"; for(int i = 1; i < colValues.Length; i++) { queryString += "," + colNames[i] + "=" + "'" + colValues[i] + "'"; } //表中已经设置成int类型的不需要再次添加单引号,而字符串类型的数据需要进行添加单引号 queryString += "WHERE" + key1 + operation + "'" + value1 + "'" + "OR" + key2 + operation + "'" + value2 + "'"; return ExecuteQuery(queryString); } /// <summary> /// 删除指定数据表内的数据 /// </summary> /// <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="operations"></param> /// <returns></returns> public SQLiteDataReader DeleteValues(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[0] + operations[0] + "'" + colValues[0] + "'"; for(int i = 1; i < colValues.Length; i++) { queryString += "AND" + " " + colNames[i] + operations[i] + "'" + colValues[i] + "'"; } return ExecuteQuery(queryString); } /// <summary> /// 创建数据表 /// </summary> /// <param name="tableName"></param> /// <param name="colNames"></param> /// <param name="colTypes"></param> /// <returns></returns> public SQLiteDataReader CreateTable(string tableName, string[] colNames, string[] colTypes) { string queryString = "CREATE TABLE IF NOT EXISTS" +" " + tableName + "(" + colNames[0] + " " + colTypes[0]; for(int i = 1; i < colNames.Length; i++) { queryString += "," + colNames[i] + " " + colTypes[i]; } queryString += ")"; return ExecuteQuery(queryString); } /// <summary> /// 根据查询条件查询 /// </summary> /// <param name="tableName"></param> /// <param name="items"></param> /// <param name="colNames"></param> /// <param name="operations"></param> /// <param name="colValues"></param> /// <returns></returns> public List<string[]> QueryTable(string tableName, string[] items, string[] colNames, string[] operations, string[] colValues) { string queryString = "SELECT" + " " + items[0] + " "; for(int i = 1; i < items.Length; i++) { queryString += "," + items[i]; } queryString += "FROM" + " " + tableName + " " + "WHERE" + " " + colNames[0] + operations[0] + "'" + colValues[0] + "'"; for(int i = 1; i < colNames.Length; i++) { queryString += "AND" + colNames[i] + " " + operations[i] + " " + "'" + colValues[i] + "'" + " "; } SQLiteDataReader dr = ExecuteQuery(queryString); List<string[]> QueryResult = new List<string[]>(); if(dr.HasRows) { while(dr.Read()) { string[] queryData = new string[dr.FieldCount]; for (int i = 0; i < dr.FieldCount; i++) { queryData[i] = dr.GetString(i); } QueryResult.Add(queryData); } } return QueryResult; } /// <summary> /// 查询整张数据表 /// </summary> /// <param name="tableName"></param> /// <returns></returns> public List<string[]> QueryTable(string tableName) { string queryString = "SELECT" + " "+ "*FROM" + " " + tableName; List<string[]> QueryResult = new List<string[]>(); if (null == QueryResult) { return null; } SQLiteDataReader dr = ExecuteQuery(queryString); if(dr.HasRows) { while(dr.Read()) { string[] queryData = new string[dr.FieldCount]; for (int i = 0; i < dr.FieldCount; i++) { queryData[i] = dr[i].ToString(); } QueryResult.Add(queryData); } } return QueryResult; } } }