/* 2021.10.14 */ using System; using System.Collections.Generic; using System.Data; using System.Data.Common; using System.Data.SQLite; using System.Text; //using Mono.Data.Sqlite; using static Apewer.Source.OrmHelper; namespace Apewer.Source { /// <summary>用于快速连接 SQLite 数据库的辅助。</summary> public class Sqlite : IDbClient { #region 基础 private Timeout _timeout = null; private string _connstring = ""; private string _path = ""; private string _pass = ""; private object _locker = new object(); /// <summary>获取或设置日志记录。</summary> public Logger Logger { get; set; } /// <summary>超时设定。</summary> public Timeout Timeout { get => _timeout; } /// <summary>创建连接实例。</summary> /// <remarks>注意:<br />- 构造函数不会创建不存在的文件;<br />- 参数 path 为文件路径,指定为空时将使用 :memory: 作为路径连接内存。</remarks> public Sqlite(string path = null, string pass = null, Timeout timeout = null) { _timeout = timeout ?? Timeout.Default; _path = path.IsEmpty() ? Memory : path; _pass = pass; if (pass.IsEmpty()) _connstring = $"data source='{_path}'; password={_pass}; version=3; "; else _connstring = $"data source='{_path}'; password={_pass}; version=3; "; } #endregion #region 连接 private SQLiteConnection _db = null; /// <summary>数据库已经连接。</summary> public bool Online { get => _db != null && _db.State == ConnectionState.Open; } /// <summary>连接字符串。</summary> public string ConnectionString { get => _connstring; } /// <summary>获取当前的 SQLiteConnection 对象。</summary> public IDbConnection Connection { get => _db; } /// <summary>连接数据库,若未连接则尝试连接。</summary> /// <returns>是否已连接。</returns> public bool Connect() { if (_db == null) { _db = new SQLiteConnection(); _db.ConnectionString = ConnectionString; } else { if (_db.State == ConnectionState.Open) return true; } try { _db.Open(); switch (_db.State) { case ConnectionState.Open: return true; default: return false; } } catch (Exception ex) { Logger.Error(nameof(Sqlite), "Connection", ex, _db.ConnectionString); Close(); return false; } } /// <summary>关闭连接,并释放对象所占用的系统资源。</summary> public void Close() { if (_db != null) { if (_transaction != null) { if (_autocommit) Commit(); else Rollback(); } lock (_locker) { _db.Dispose(); } _db = null; } } /// <summary>关闭连接,释放对象所占用的系统资源,并清除连接信息。</summary> public void Dispose() { Close(); } #endregion #region Transaction private IDbTransaction _transaction = null; private bool _autocommit = false; /// <summary>启动事务。</summary> public string Begin(bool commit = true) => Begin(commit, null); /// <summary>启动事务。</summary> public string Begin(bool commit, Class<IsolationLevel> isolation) { if (!Connect()) return "未连接。"; if (_transaction != null) return "存在已启动的事务,无法再次启动。"; try { _transaction = isolation ? _db.BeginTransaction(isolation.Value) : _db.BeginTransaction(); _autocommit = commit; return null; } catch (Exception ex) { Logger.Error(nameof(Sqlite), "Begin", ex.Message()); return ex.Message(); } } /// <summary>提交事务。</summary> public string Commit() { if (_transaction == null) return "事务不存在。"; try { _transaction.Commit(); RuntimeUtility.Dispose(_transaction); _transaction = null; return null; } catch (Exception ex) { RuntimeUtility.Dispose(_transaction); _transaction = null; Logger.Error(nameof(Sqlite), "Commit", ex.Message()); return ex.Message(); } } /// <summary>从挂起状态回滚事务。</summary> public string Rollback() { if (_transaction == null) return "事务不存在。"; try { _transaction.Rollback(); RuntimeUtility.Dispose(_transaction); _transaction = null; return null; } catch (Exception ex) { RuntimeUtility.Dispose(_transaction); _transaction = null; Logger.Error(nameof(Sqlite), "Rollback", ex.Message()); return ex.Message(); } } #endregion #region SQL /// <summary>查询。</summary> public IQuery Query(string sql) => Query(sql, null); /// <summary>查询。</summary> public IQuery Query(string sql, IEnumerable<IDataParameter> parameters) { if (string.IsNullOrEmpty(sql)) return Example.InvalidQueryStatement; var connected = Connect(); if (!connected) return Example.InvalidQueryConnection; var query = new Query(); try { using (var command = new SQLiteCommand()) { command.Connection = _db; command.CommandTimeout = _timeout.Query; command.CommandText = sql; if (parameters != null) { foreach (var p in parameters) { if (p != null) command.Parameters.Add(p); } } using (var dataset = new DataSet()) { using (var da = new SQLiteDataAdapter(sql, _db)) { const string name = "result"; da.Fill(dataset, name); var table = dataset.Tables[name]; return new Query(table); } } } } catch (Exception ex) { Logger.Error(nameof(Sqlite), "Query", ex, sql); return new Query(ex); } } /// <summary>执行单条 Transact-SQL 语句。</summary> public IExecute Execute(string sql) => Execute(sql, null); /// <summary>执行单条 Transact-SQL 语句,并加入参数。</summary> public IExecute Execute(string sql, IEnumerable<IDataParameter> parameters) { if (string.IsNullOrEmpty(sql)) return Example.InvalidExecuteStatement; var connected = Connect(); if (!connected) return Example.InvalidExecuteConnection; lock (_locker) { var inTransaction = _transaction != null; if (!inTransaction) Begin(); try { using (var command = new SQLiteCommand()) { command.Connection = _db; command.Transaction = (SQLiteTransaction)_transaction; command.CommandTimeout = _timeout.Execute; command.CommandText = sql; if (parameters != null) { foreach (var p in parameters) { if (p != null) command.Parameters.Add(p); } } var rows = command.ExecuteNonQuery(); if (!inTransaction) Commit(); // todo 此处应该检查事务提交产生的错误。 return new Execute(true, rows); } } catch (Exception ex) { Logger.Error(nameof(Sqlite), "Execute", ex, sql); if (!inTransaction) Rollback(); return new Execute(ex); } } } #endregion #region 属性。 /// <summary>保存当前数据库到文件,若文件已存在则将重写文件。</summary> public bool Save(string path, string pass = null) { if (!StorageUtility.CreateFile(path, 0, true)) { Logger.Error(nameof(Sqlite), "Save", TextUtility.Merge("创建文件 ", path, " 失败。")); return false; } using (var destination = new Sqlite(path, pass)) return Save(destination); } /// <summary>保存当前数据库到目标数据库。</summary> public bool Save(Sqlite destination) => string.IsNullOrEmpty(Backup(this, destination)); /// <summary>加载文件到当前数据库。</summary> public bool Load(string path, string pass = null) { using (var source = new Sqlite(path, pass)) return Load(source); } /// <summary>加载源数据库到当前数据库。</summary> public bool Load(Sqlite source) => string.IsNullOrEmpty(Backup(source, this)); #endregion #region ORM /// <summary>查询数据库中的所有表名。</summary> public string[] TableNames() { var list = new List<string>(); if (Connect()) { var sql = "select name from sqlite_master where type='table' order by name; "; var query = (Query)Query(sql); for (int r = 0; r < query.Rows; r++) { var cell = query.Text(r, 0); if (TextUtility.IsBlank(cell)) continue; list.Add(cell); } query.Dispose(); } return list.ToArray(); } /// <summary>查询数据库中的所有视图名。</summary> public string[] ViewNames() { var list = new List<string>(); if (Connect()) { var sql = "select name from sqlite_master where type='view' order by name; "; var query = (Query)Query(sql); for (int r = 0; r < query.Rows; r++) { var cell = query.Text(r, 0); if (TextUtility.IsBlank(cell)) continue; list.Add(cell); } query.Dispose(); } return list.ToArray(); } /// <summary>查询表中的所有列名。</summary> public string[] ColumnNames(string table) { var list = new List<string>(); if (Connect()) { var t = TextUtility.AntiInject(table); var sql = TextUtility.Merge("pragma table_info('", TextUtility.AntiInject(t), "'); "); using (var query = Query(sql) as Query) { for (int r = 0; r < query.Rows; r++) { var cell = query.Text(r, "name"); if (TextUtility.IsBlank(cell)) continue; list.Add(cell); } } } return list.ToArray(); } /// <summary>创建表,不修改已存在表。成功时返回空字符串,发生异常时返回异常信息。</summary> public string Initialize(Record model) => model == null ? "参数无效。" : Initialize(model.GetType()); /// <summary>创建表,不修改已存在表。成功时返回空字符串,发生异常时返回异常信息。</summary> public string Initialize<T>() where T : class, new() => Initialize(typeof(T)); /// <summary>创建表,不修改已存在表。当现存表中缺少模型中属性对应的列时增加列。成功时返回空字符串,发生异常时返回异常信息。</summary> public string Initialize(Type model) { var structure = TableStructure.Parse(model); if (structure == null) return "无法解析记录模型。"; // 连接数据库。 if (!Connect()) return "连接数据库失败。"; // 检查现存表。 var exists = false; var tables = TableNames(); if (tables.Length > 0) { var lower = structure.Name.ToLower(); foreach (var table in tables) { if (TextUtility.IsBlank(table)) continue; if (table.ToLower() == lower) { exists = true; break; } } } if (exists) { return TextUtility.Merge("指定的表已经存在。"); } else { var sqlcolumns = new List<string>(); foreach (var column in structure.Columns) { var type = GetColumnDeclaration(column); if (type == TextUtility.Empty) return TextUtility.Merge("类型 ", column.Type.ToString(), " 不受支持。"); sqlcolumns.Add(type); } var sql = TextUtility.Merge("create table [", structure.Name, "](", TextUtility.Join(", ", sqlcolumns), "); "); var execute = Execute(sql); if (execute.Success) return TextUtility.Empty; return execute.Message; } } /// <summary>插入记录。返回错误信息。</summary> public string Insert(object record) { if (record == null) return "参数无效。"; OrmHelper.FixProperties(record); var structure = TableStructure.Parse(record.GetType()); if (structure == null) return "无法解析记录模型。"; var parameters = structure.CreateParameters(record, CreateDataParameter); var sql = GenerateInsertStatement(structure.Name, (IEnumerable<IDataParameter>)parameters); var execute = Execute(sql, parameters); if (execute.Success && execute.Rows > 0) return TextUtility.Empty; return execute.Message; } /// <summary>更新记录,实体中的 Key 属性不被更新。返回错误信息。</summary> /// <remarks>无法更新带有 Independent 特性的模型(缺少 Key 属性)。</remarks> public string Update(IRecord record) { if (record == null) return "参数无效。"; FixProperties(record); SetUpdated(record); var structure = TableStructure.Parse(record.GetType()); if (structure == null) return "无法解析记录模型。"; if (structure.Independent) return "无法更新带有 Independent 特性的模型。"; var parameters = structure.CreateParameters(record, CreateDataParameter, "_key"); var sql = GenerateUpdateStatement(structure.Name, record.Key, parameters); var execute = Execute(sql, parameters); if (execute.Success && execute.Rows > 0) return TextUtility.Empty; return execute.Message; } /// <summary>获取按指定语句查询到的所有记录。</summary> public Result<object[]> Query(Type model, string sql) => OrmHelper.Query(this, model, sql); /// <summary>获取按指定语句查询到的所有记录。</summary> public Result<T[]> Query<T>(string sql) where T : class, new() => OrmHelper.Query<T>(this, sql); /// <summary>查询多条记录。</summary> public Result<object[]> Query(Type model, long flag = 0) => OrmHelper.Query(this, model, (tn) => { if (flag == 0) return $"select * from [{tn}]; "; return $"select * from [{tn}] where _flag={flag}; "; }); /// <summary>查询多条记录。</summary> public Result<T[]> Query<T>(long flag = 0) where T : class, IRecord, new() => OrmHelper.Query<T>(this, (tn) => { if (flag == 0) return $"select * from [{tn}]; "; return $"select * from [{tn}] where _flag={flag}; "; }); /// <summary>获取具有指定 Key 的记录。</summary> public Result<IRecord> Get(Type model, string key, long flag = 0) => OrmHelper.Get(this, model, key, (tn, sk) => { if (flag == 0) return $"select * from [{tn}] where _key='{sk}' limit 1; "; return $"select * from [{tn}] where _flag={flag} and _key='{sk}' limit 1; "; }); /// <summary>获取具有指定 Key 的记录。</summary> public Result<T> Get<T>(string key, long flag) where T : class, IRecord, new() => OrmHelper.Get<T>(this, key, (tn, sk) => { if (flag == 0) return $"select * from [{tn}] where _key='{sk}' limit 1; "; return $"select * from [{tn}] where _flag={flag} and _key='{sk}' limit 1; "; }); /// <summary>获取指定类型的主键,按 Flag 属性筛选。</summary> public Result<string[]> Keys(Type model, long flag = 0) => OrmHelper.Keys(this, model, (tn) => { if (flag == 0) return $"select _key from [{tn}] where _flag={flag}; "; return $"select _key from [{tn}]; "; }); /// <summary>>获取指定类型的主键,按 Flag 属性筛选。</summary> public Result<string[]> Keys<T>(long flag = 0) where T : class, IRecord, new() => Keys(typeof(T), flag); #endregion #region static /// <summary>对文本转义,符合 SQL 安全性。可根据字段类型限制 UTF-8 字节数,默认为 0 时不限制字节数。</summary> public static string Escape(string text, int bytes = 0) { if (text.IsEmpty()) return ""; var t = text ?? ""; t = t.Replace("\\", "\\\\"); t = t.Replace("'", "\\'"); t = t.Replace("\n", "\\n"); t = t.Replace("\r", "\\r"); t = t.Replace("\b", "\\b"); t = t.Replace("\t", "\\t"); t = t.Replace("\f", "\\f"); if (bytes > 5) { if (t.Bytes(Encoding.UTF8).Length > bytes) { while (true) { t = t.Substring(0, t.Length - 1); if (t.Bytes(Encoding.UTF8).Length <= (bytes - 4)) break; } t = t + " ..."; } } return t; } private static string GetColumnTypeName(ColumnType type) { switch (type) { case ColumnType.Bytes: return "blob"; case ColumnType.Integer: return "integer"; case ColumnType.Float: return "float"; case ColumnType.VarChar: case ColumnType.VarChar191: case ColumnType.VarCharMax: return "varchar"; case ColumnType.Text: return "text"; case ColumnType.NVarChar: case ColumnType.NVarChar191: case ColumnType.NVarCharMax: return "nvarchar"; case ColumnType.NText: return "ntext"; default: return null; } } private static string GetColumnDeclaration(ColumnAttribute column) { var type = TextUtility.Empty; var length = NumberUtility.Restrict(column.Length, 0, 255).ToString(); switch (column.Type) { case ColumnType.Bytes: type = "blob"; break; case ColumnType.Integer: type = "integer"; break; case ColumnType.Float: type = "real"; break; case ColumnType.VarChar: type = TextUtility.Merge("varchar(", length, ")"); break; case ColumnType.VarChar191: type = TextUtility.Merge("varchar(191)"); break; case ColumnType.VarCharMax: type = TextUtility.Merge("varchar(255)"); break; case ColumnType.Text: type = TextUtility.Merge("text"); break; case ColumnType.NVarChar: type = TextUtility.Merge("nvarchar(", length, ")"); break; case ColumnType.NVarChar191: type = TextUtility.Merge("nvarchar(191)"); break; case ColumnType.NVarCharMax: type = TextUtility.Merge("nvarchar(255)"); break; case ColumnType.NText: type = TextUtility.Merge("ntext"); break; default: return TextUtility.Empty; } return TextUtility.Merge("[", (object)column.Field, "] ", type); } /// <summary>创建参数。</summary> /// <exception cref="ArgumentNullException"></exception> /// <exception cref="InvalidOperationException"></exception> public static SQLiteParameter CreateDataParameter(Parameter parameter) { if (parameter == null) throw new InvalidOperationException("参数无效。"); return CreateDataParameter(parameter.Name, parameter.Type, parameter.Size, parameter.Value); } /// <summary>创建参数。</summary> public static SQLiteParameter CreateDataParameter(string name, ColumnType type, int size, object value) { var n = TextUtility.Trim(name); if (TextUtility.IsBlank(n)) return null; var t = GetColumnTypeName(type); var s = size; switch (type) { case ColumnType.VarChar: s = NumberUtility.Restrict(s, 0, 8000); break; case ColumnType.NVarChar: s = NumberUtility.Restrict(s, 0, 4000); break; case ColumnType.VarChar191: case ColumnType.NVarChar191: s = NumberUtility.Restrict(s, 0, 191); break; case ColumnType.VarCharMax: case ColumnType.NVarCharMax: s = NumberUtility.Restrict(s, 0, 255); break; default: s = 0; break; } var v = value; if (v is string && v != null && s > 0) { v = TextUtility.Left((string)v, s); } var p = new SQLiteParameter(); p.ParameterName = n; p.TypeName = t; p.Value = v; if (s > 0) p.Size = s; return p; } /// <summary>创建参数。</summary> public static SQLiteParameter CreateDataParameter(string name, string type, int size, object value) { var v = value; if (value is string && value != null && size > 0) { v = TextUtility.Left((string)value, size); } var p = new SQLiteParameter(); p.ParameterName = name; p.TypeName = type; p.Value = v; p.Size = size; return p; } /// <summary>创建参数。</summary> public static SQLiteParameter CreateDataParameter(string name, string type, object value) { var p = new SQLiteParameter(); p.ParameterName = name; p.TypeName = type; p.Value = value; return p; } /// <summary>备份数据库,返回错误信息。</summary> public static string Backup(Sqlite source, Sqlite destination) { if (source == null) return "SQLite Backup Failed: Invalid Source"; if (destination == null) return "SQLite Backup Failed: Invalid Destination"; if (!source.Connect()) return "SQLite Backup Failed: Invalid Source Connection"; if (!destination.Connect()) return "SQLite Backup Failed: Invalid Destination Connection"; lock (source._locker) { lock (destination._locker) { try { source._db.BackupDatabase(destination._db, "main", "main", -1, null, 0); return ""; } catch (Exception ex) { return "SQLite Load Failed: " + ex.Message; } } } } /// <summary>创建参数。</summary> public static IDbDataParameter CreateParameter(string field, DbType type, int size, object value) { var p = new SQLiteParameter(); p.ParameterName = field; p.DbType = type; p.Size = size; p.Value = value; return p; } /// <summary>创建参数。</summary> public static IDbDataParameter CreateParameter(string field, DbType type, object value) { var p = new SQLiteParameter(); p.ParameterName = field; p.DbType = type; p.Value = value; return p; } /// <summary>整理数据库,压缩未使用的空间。</summary> public const string Vacuum = "vacuum"; /// <summary>内存数据库的地址。</summary> public const string Memory = ":memory:"; #endregion #region 生成 SQL 语句 /// <summary>生成 INSERT INTO 语句。表名必须有效,无有效参数时将获取空结果。</summary> /// <exception cref="System.ArgumentException"></exception> /// <exception cref="System.ArgumentNullException"></exception> public static string GenerateInsertStatement(string table, IEnumerable<IDataParameter> parameters) { if (table == null) throw new ArgumentNullException(nameof(table)); var t = TextUtility.AntiInject(table, 255); if (TextUtility.IsBlank(t)) throw new ArgumentException("表名无效。", nameof(table)); var cs = GetParametersNames(parameters); if (cs.Count < 1) return TextUtility.Empty; return GenerateInsertStatement(t, cs); } private static string GetParameterName(string parameter) { var name = TextUtility.AntiInject(parameter, 255); if (name.StartsWith("@") && name.Length > 1) { name = name.Substring(1, name.Length - 1); } return name; } private static string GetParameterName(IDataParameter parameter) { var name = TextUtility.Empty; if (parameter != null) { name = GetParameterName(parameter.ParameterName); } return name; } private static List<string> GetParametersNames(IEnumerable<IDataParameter> parameters) { var columns = new List<string>(); if (parameters != null) { foreach (var parameter in parameters) { var name = GetParameterName(parameter); var isblank = TextUtility.IsBlank(name); if (isblank) continue; columns.Add(name); } } return columns; } private static string GenerateInsertStatement(string table, List<string> columns) { var r = TextUtility.Empty; var t = TextUtility.AntiInject(table, 255); if (columns != null && !TextUtility.IsBlank(t)) { var count = 0; var names = new List<string>(); var values = new List<string>(); foreach (var column in columns) { //names.Add(TextGenerator.Merge("[", column, "]")); names.Add(TextUtility.Merge(column)); values.Add("@" + column); count += 1; } var sb = new StringBuilder(); if (count > 0) { sb.Append("insert into [", t, "](", TextUtility.Join(", ", names), ") "); sb.Append("values(", TextUtility.Join(", ", values), "); "); } r = sb.ToString(); } return r; } private static string GenerateUpdateStatement(string table, string key, List<string> columns) { var result = TextUtility.Empty; var t = TextUtility.AntiInject(table, 255); var k = TextUtility.AntiInject(key, 255); if (columns != null && !TextUtility.IsBlank(t) && !TextUtility.IsBlank(k)) { var items = new List<string>(); foreach (var column in columns) { items.Add(TextUtility.Merge("[", column, "]=@", column)); } if (items.Count > 0) { result = TextUtility.Merge("update [", t, "] set ", TextUtility.Join(", ", items), " where [_key]='", k, "'; "); } } return result; } /// <summary>生成 UPDATE 语句,键字段名为“_key”。表名必须有效,键值必须有效,无有效参数时将获取空结果。</summary> /// <exception cref="System.ArgumentException"></exception> /// <exception cref="System.ArgumentNullException"></exception> public static string GenerateUpdateStatement(string table, string key, IEnumerable<IDataParameter> parameters) { if (table == null) throw new ArgumentNullException("argTable"); var t = TextUtility.AntiInject(table, 255); if (TextUtility.IsBlank(t)) throw new ArgumentException("表名无效。", nameof(table)); if (key == null) throw new ArgumentNullException("argKey"); var k = TextUtility.AntiInject(key, 255); if (TextUtility.IsBlank(k)) throw new ArgumentException("键值无效。", nameof(key)); var columns = GetParametersNames(parameters); if (columns.Count < 1) return TextUtility.Empty; return GenerateUpdateStatement(t, k, columns); } #endregion } }