using System; using System.Collections.Generic; using System.Data; using System.Data.SQLite; using System.IO; using System.Text; //using Mono.Data.Sqlite; using static Apewer.Source.SourceUtility; namespace Apewer.Source { /// 连接 SQLite 数据库的客户端。 /// Require System.Data.SQLite.Core v1.0.110 public class Sqlite : DbClient { #region connection private SQLiteConnection _conn = null; private string _connstr = null; private string _path = null; private string _pass = null; /// 连接字符串。 public override string ConnectionString => _connstr; /// 当前数据库的文件路径。 public string Path { get => _path; } /// 使用现有的连接创建实例。 /// 有效的 SQLite 连接。 /// 超时设定。 /// /// public Sqlite(IDbConnection connection, Timeout timeout = null) : base(timeout) { if (connection == null) throw new ArgumentNullException(nameof(connection), "指定的连接无效。"); var conn = connection as SQLiteConnection; if (conn == null) throw new ArgumentException(nameof(connection), "指定的连接不是支持的类型。"); _conn = conn; _connstr = conn.ConnectionString; } /// 创建连接实例。 /// 数据库的文件路径,指定为空时将使用 :memory: 作为路径。 /// 连接数据库的密码,使用内存数据库时此参数将被忽略。 /// 超时设定。 /// /// /// /// /// public Sqlite(string path = null, string pass = null, Timeout timeout = null) : base(timeout) { // 使用内存。 if (string.IsNullOrEmpty(path) || path.ToLower() == Memory) { _connstr = "data source=':memory:'; version=3; "; _path = Memory; return; } // 使用文件。 if (!File.Exists(path)) { var dir = Directory.GetParent(path).FullName; if (!Directory.Exists(dir)) Directory.CreateDirectory(dir); File.Create(path).Dispose(); } _connstr = $"data source='{path}'; version=3; "; _path = path; if (!string.IsNullOrEmpty(pass)) { pass = pass.Trim(); if (!string.IsNullOrEmpty(pass)) { _connstr += $"password={_pass}; "; _pass = pass; } } } /// /// 挂载数据库。 /// attach database "" as "" /// public string Attach(string path, string alias) { if (path.IsEmpty()) return "未指定数据库路径。"; if (alias.IsEmpty()) return "未指定别名。"; var connect = Connect(); if (connect.NotEmpty()) return connect; var sql = $"attach database \"{path}\" as \"{alias}\""; var execute = Execute(sql, null, false) as Execute; return execute.Success ? null : execute.Message; } /// /// 卸载数据库。 /// detach database "" /// public string Detach(string alias) { if (alias.IsEmpty()) return "未指定别名。"; var connect = Connect(); if (connect.NotEmpty()) return connect; var sql = $"detach \"{alias}\""; var execute = Execute(sql, null, false) as Execute; return execute.Success ? null : execute.Message; } #endregion #region public /// public override string[] StoreNames() => throw new NotImplementedException(); /// public override string[] TableNames() => QueryStrings("select name from sqlite_master where type='table' order by name"); /// public override string[] ColumnNames(string tableName) => QueryStrings($"pragma table_info('{tableName.SafeName()}'); "); /// 插入记录。返回错误信息。 public override string Insert(object record, string table = null, bool adjust = true) { if (record == null) return "参数无效。"; if (adjust) SourceUtility.FixProperties(record); // 解析模型,获取表名。 var structure = TableStructure.Parse(record.GetType()); if (structure == null) return "无法解析记录模型。"; if (string.IsNullOrEmpty(table)) table = structure.TableName; if (string.IsNullOrEmpty(table)) return "表名称无效。"; // 排除字段。 var excluded = new List(); foreach (var ca in structure.Columns) { // 排除不使用 ORM 的属性。 if (ca.Independent || ca.Incremental) excluded.Add(ca.Field); } // 准备参数。 var ps = structure.CreateParameters(record, Parameter, excluded); var psc = ps.Length; if (psc < 1) return "数据模型不包含字段。"; // 合成 SQL 语句。 var sb = new StringBuilder(); sb.Append("insert into "); sb.Append(table); sb.Append("("); for (var i = 0; i < psc; i++) { if (i > 0) sb.Append(", "); sb.Append(ps[i].ParameterName); } sb.Append(") values("); for (var i = 0; i < psc; i++) { if (i > 0) sb.Append(", "); sb.Append("@"); sb.Append(ps[i].ParameterName); } sb.Append("); "); var sql = sb.ToString(); // 执行。 var execute = Execute(sql, ps, false); if (execute.Success && execute.Rows > 0) return TextUtility.Empty; return execute.Message; } /// 更新记录,实体中的 Key 属性不被更新。返回错误信息。 /// 无法更新带有 Independent 特性的模型(缺少 Key 属性)。 public override string Update(IRecord record, string table = null, bool adjust = true) { if (record == null) return "参数无效。"; if (adjust) { FixProperties(record); SetUpdated(record); } // 解析模型,获取表名。 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。"; if (string.IsNullOrEmpty(table)) table = structure.TableName; if (string.IsNullOrEmpty(table)) return "表名称无效。"; // 排除字段。 var excluded = new List(); if (structure.Key != null) excluded.Add(structure.Key.Field); foreach (var ca in structure.Columns) { // 排除不使用 ORM 的属性、自增属性和主键属性。 if (ca.Independent || ca.Incremental || ca.PrimaryKey || ca.NoUpdate) excluded.Add(ca.Field); } // 准备参数。 var ps = structure.CreateParameters(record, Parameter, excluded); var psc = ps.Length; if (psc < 1) return "数据模型不包含字段。"; // 合成 SQL 语句。 var cs = new List(); foreach (var p in ps) cs.Add($"[{p.ParameterName}] = @{p.ParameterName}"); var sql = $"update {table} set {string.Join(", ", cs.ToArray())} where [{structure.Key.Field}] = '{record.Key.SafeKey()}'"; // 执行。 var execute = Execute(sql, ps, false); if (execute.Success && execute.Rows > 0) return TextUtility.Empty; return execute.Message; } #endregion #region protected /// protected override string Initialize(TableStructure structure, string table) { if (string.IsNullOrEmpty(table)) table = structure.TableName; // 检查现存表。 var exists = false; var tables = TableNames(); if (tables.Length > 0) { var lower = table.ToLower(); foreach (var tn in tables) { if (TextUtility.IsEmpty(tn)) continue; if (tn.ToLower() == lower) { exists = true; break; } } } if (exists) { return TextUtility.Merge("指定的表已经存在。"); } else { var sqlcolumns = new List(); foreach (var column in structure.Columns) { var type = Declaration(column); if (string.IsNullOrEmpty(type)) { return TextUtility.Merge("类型 ", column.Type.ToString(), " 不受支持。"); } if (!column.Independent) { if (column.PrimaryKey) type = type + " primary key"; } sqlcolumns.Add(type); } var sql = TextUtility.Merge("create table [", table, "](", TextUtility.Join(", ", sqlcolumns), "); "); var execute = Execute(sql, null, false); if (execute.Success) return TextUtility.Empty; return execute.Message; } } /// protected override IDataAdapter CreateDataAdapter(IDbCommand command) => new SQLiteDataAdapter((SQLiteCommand)command); /// protected override IDbConnection GetConnection() { if (_conn == null) _conn = new SQLiteConnection(_connstr); return _conn; } /// protected override IDataParameter CreateParameter() => new SQLiteParameter(); /// protected override string Keys(string tableName, string keyField, string flagField, long flagValue) { if (flagValue == 0) return $"select [{keyField}] from [{tableName}] where [{flagField}] = {flagValue}"; return $"select [{keyField}] from [{tableName}]"; } /// protected override string Get(string tableName, string keyField, string keyValue, string flagField, long flagValue) { if (flagValue == 0) return $"select * from [{tableName}] where [{keyField}] = '{keyValue}' limit 1"; else return $"select * from [{tableName}] where [{keyField}] = '{keyValue}' and [{flagField}] = {flagValue} limit 1"; } /// protected override string List(string tableName, string flagField, long flagValue) { if (flagValue == 0) return $"select * from [{tableName}]"; else return $"select * from [{tableName}] where [{flagField}] = {flagValue}"; } #endregion #region special /// 整理数据库,压缩未使用的空间。 public const string Vacuum = "vacuum"; /// 内存数据库的地址。 public const string Memory = ":memory:"; /// 查询数据库中的所有视图名。 public string[] ViewNames() => QueryStrings("select name from sqlite_master where type='view' order by name"); #endregion #region mirror /// 保存当前数据库到文件,若文件已存在则将重写文件。 public string Save(string path, string pass = null) { if (path.IsEmpty()) return "参数 path 无效。"; if (!StorageUtility.CreateFile(path, 0, true)) { var msg = $"创建文件 {path} 失败。"; Logger.Error(nameof(Sqlite), "Save", msg); return msg; } using (var destination = new Sqlite(path, pass)) return Save(destination); } /// 保存当前数据库到目标数据库。 public string Save(Sqlite destination) => Backup(this, destination); /// 加载文件到当前数据库。 public string Load(string path, string pass = null) { using (var source = new Sqlite(path, pass)) return Load(source); } /// 加载源数据库到当前数据库。 public string Load(Sqlite source) => Backup(source, this); /// 备份数据库,返回错误信息。 string Backup(Sqlite source, Sqlite destination) { if (source == null) return "备份失败:源无效。"; if (destination == null) return "备份失败:目标无效。"; var sConnect = source.Connect(); if (sConnect.NotEmpty()) return sConnect; var dConnect = source.Connect(); if (dConnect.NotEmpty()) return dConnect; try { var src = (SQLiteConnection)source.Connection; var dst = (SQLiteConnection)destination.Connection; src.BackupDatabase(dst, "main", "main", -1, null, 0); return ""; } catch (Exception ex) { var msg = "备份失败:" + ex.Message; Logger?.Error(this, msg); return msg; } } #endregion #region type & parameter 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 Declaration(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.DateTime: type = "datetime"; 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("[", column.Field, "] ", type); } /// 创建参数。 /// /// public static SQLiteParameter Parameter(Parameter parameter) { if (parameter == null) throw new InvalidOperationException("参数无效。"); return Parameter(parameter.Name, parameter.Type, parameter.Size, parameter.Value); } /// 创建参数。 public static SQLiteParameter Parameter(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 ?? DBNull.Value; if (s > 0) p.Size = s; return p; } /// 创建参数。 public static IDbDataParameter Parameter(string field, DbType type, int size, object value) { var p = new SQLiteParameter(); p.ParameterName = field; p.DbType = type; p.Size = size; p.Value = value ?? DBNull.Value; return p; } /// 创建参数。 public static IDbDataParameter Parameter(string field, DbType type, object value) { var p = new SQLiteParameter(); p.ParameterName = field; p.DbType = type; p.Value = value ?? DBNull.Value; return p; } #endregion } }