using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Common;
using System.Diagnostics;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Web;
using NewLife;
using NewLife.Collections;
using NewLife.Log;
using NewLife.Reflection;
using XCode.Exceptions;
namespace XCode.DataAccessLayer
{
/// <summary>数据库会话基类</summary>
abstract partial class DbSession : DisposeBase, IDbSession
{
#region 构造函数
protected DbSession(IDatabase db)
{
Database = db;
ShowSQL = db.ShowSQL;
}
/// <summary>销毁资源时,回滚未提交事务,并关闭数据库连接</summary>
/// <param name="disposing"></param>
protected override void OnDispose(Boolean disposing)
{
base.OnDispose(disposing);
try
{
// 注意,没有Commit的数据,在这里将会被回滚
//if (Trans != null) Rollback();
// 在嵌套事务中,Rollback只能减少嵌套层数,而_Trans.Rollback能让事务马上回滚
if (Opened) Transaction?.Rollback();
if (_Conn != null) Close();
if (_Conn != null)
{
var conn = _Conn;
_Conn = null;
conn.Dispose();
}
}
catch (ObjectDisposedException) { }
catch (Exception ex)
{
WriteLog("执行" + DbType.ToString() + "的Dispose时出错:" + ex.ToString());
}
}
#endregion
#region 属性
/// <summary>数据库</summary>
public IDatabase Database { get; }
/// <summary>返回数据库类型。外部DAL数据库类请使用Other</summary>
private DatabaseType DbType { get { return Database.Type; } }
/// <summary>工厂</summary>
private DbProviderFactory Factory { get { return Database.Factory; } }
/// <summary>链接字符串,会话单独保存,允许修改,修改不会影响数据库中的连接字符串</summary>
public String ConnectionString { get; set; }
private DbConnection _Conn;
/// <summary>数据连接对象。</summary>
public DbConnection Conn
{
get
{
if (_Conn == null)
{
try
{
_Conn = Factory.CreateConnection();
}
catch (ObjectDisposedException) { this.Dispose(); throw; }
//_Conn.ConnectionString = Database.ConnectionString;
checkConnStr();
_Conn.ConnectionString = ConnectionString;
}
return _Conn;
}
//set { _Conn = value; }
}
protected void checkConnStr()
{
if (ConnectionString.IsNullOrWhiteSpace())
throw new XCodeException("[{0}]未指定连接字符串!", Database == null ? "" : Database.ConnName);
}
/// <summary>查询次数</summary>
public Int32 QueryTimes { get; set; }
/// <summary>执行次数</summary>
public Int32 ExecuteTimes { get; set; }
/// <summary>线程编号,每个数据库会话应该只属于一个线程,该属性用于检查错误的跨线程操作</summary>
public Int32 ThreadID { get; } = Thread.CurrentThread.ManagedThreadId;
#endregion
#region 打开/关闭
/// <summary>连接是否已经打开</summary>
public Boolean Opened { get { return _Conn != null && _Conn.State != ConnectionState.Closed; } }
/// <summary>打开</summary>
public virtual void Open()
{
var tid = Thread.CurrentThread.ManagedThreadId;
if (ThreadID != tid) DAL.WriteLog("本会话由线程{0}创建,当前线程{1}非法使用该会话!", ThreadID, tid);
var conn = Conn;
if (conn != null && conn.State == ConnectionState.Closed)
{
try
{
conn.Open();
}
catch (DbException)
{
DAL.WriteLog("Open错误:{0}", conn.ConnectionString);
throw;
}
}
}
/// <summary>关闭</summary>
public virtual void Close()
{
var conn = _Conn;
if (conn != null)
{
try { if (conn.State != ConnectionState.Closed) conn.Close(); }
catch (ObjectDisposedException) { }
catch (Exception ex)
{
WriteLog("{0}.Close出错:{1}", DbType, ex);
}
}
}
/// <summary>自动关闭。启用事务后,不关闭连接。</summary>
public void AutoClose()
{
if (Transaction == null && Opened) Close();
}
/// <summary>数据库名</summary>
public String DatabaseName
{
get { return Conn?.Database; }
set
{
if (DatabaseName == value) return;
// 因为MSSQL多次出现因连接字符串错误而导致的报错,连接字符串变错设置变空了,这里统一关闭连接,采用保守做法修改字符串
var b = Opened;
if (b) Close();
//如果没有打开,则改变链接字符串
var builder = new XDbConnectionStringBuilder();
builder.ConnectionString = ConnectionString;
var flag = false;
if (builder.ContainsKey("Database"))
{
builder["Database"] = value;
flag = true;
}
else if (builder.ContainsKey("Initial Catalog"))
{
builder["Initial Catalog"] = value;
flag = true;
}
if (flag)
{
var connStr = builder.ToString();
ConnectionString = connStr;
Conn.ConnectionString = connStr;
}
if (b) Open();
}
}
/// <summary>当异常发生时触发。关闭数据库连接,或者返还连接到连接池。</summary>
/// <param name="ex"></param>
/// <returns></returns>
protected virtual XDbException OnException(Exception ex)
{
if (Transaction == null && Opened) Close(); // 强制关闭数据库
if (ex != null)
return new XDbSessionException(this, ex);
else
return new XDbSessionException(this);
}
/// <summary>当异常发生时触发。关闭数据库连接,或者返还连接到连接池。</summary>
/// <param name="ex"></param>
/// <param name="cmd"></param>
/// <returns></returns>
protected virtual XSqlException OnException(Exception ex, DbCommand cmd)
{
if (Transaction == null && Opened) Close(); // 强制关闭数据库
var sql = GetSql(cmd);
if (ex != null)
return new XSqlException(sql, this, ex);
else
return new XSqlException(sql, this);
}
#endregion
#region 事务
/// <summary>数据库事务</summary>
public ITransaction Transaction { get; private set; }
/// <summary>开始事务</summary>
/// <remarks>
/// Read Uncommitted: 允许读取脏数据,一个事务能看到另一个事务还没有提交的数据。(不会阻止其它操作)
/// Read Committed: 确保事务读取的数据都必须是已经提交的数据。它限制了读取中间的,没有提交的,脏的数据。
/// 但是它不能确保当事务重新去读取的时候,读的数据跟上次读的数据是一样的,也就是说当事务第一次读取完数据后,
/// 该数据是可能被其他事务修改的,当它再去读取的时候,数据可能是不一样的。(数据隐藏,不阻止)
/// Repeatable Read: 是一个更高级别的隔离级别,如果事务再去读取同样的数据,先前的数据是没有被修改过的。(阻止其它修改)
/// Serializable: 它做出了最有力的保证,除了每次读取的数据是一样的,它还确保每次读取没有新的数据。(阻止其它添删改)
/// </remarks>
/// <param name="level">事务隔离等级</param>
/// <returns>剩下的事务计数</returns>
public virtual Int32 BeginTransaction(IsolationLevel level)
{
if (Disposed) throw new ObjectDisposedException(this.GetType().Name);
var tr = Transaction;
if (tr != null) return tr.Begin().Count;
try
{
tr = new Transaction(this, level);
tr.Completed += (s, e) => { Transaction = null; AutoClose(); };
Transaction = tr;
return tr.Count;
}
catch (DbException ex)
{
throw OnException(ex);
}
}
/// <summary>提交事务</summary>
/// <returns>剩下的事务计数</returns>
public virtual Int32 Commit()
{
var tr = Transaction;
if (tr == null) throw new XDbSessionException(this, "当前并未开始事务,请用BeginTransaction方法开始新事务!");
try
{
tr.Commit();
}
catch (DbException ex)
{
throw OnException(ex);
}
return tr.Count;
}
/// <summary>回滚事务</summary>
/// <param name="ignoreException">是否忽略异常</param>
/// <returns>剩下的事务计数</returns>
public Int32 Rollback(Boolean ignoreException = true)
{
var tr = Transaction;
if (tr == null) throw new XDbSessionException(this, "当前并未开始事务,请用BeginTransaction方法开始新事务!");
//// 输出事务日志
//if (tr.Count == 1 && Setting.Current.TransactionDebug) XTrace.DebugStack();
try
{
tr.Rollback();
}
catch (DbException ex)
{
if (!ignoreException) throw OnException(ex);
}
return tr.Count;
}
#endregion
#region 基本方法 查询/执行
/// <summary>执行SQL查询,返回记录集</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型,默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public virtual DataSet Query(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
return Query(OnCreateCommand(sql, type, ps));
}
/// <summary>执行DbCommand,返回记录集</summary>
/// <param name="cmd">DbCommand</param>
/// <returns></returns>
public virtual DataSet Query(DbCommand cmd)
{
cmd.Transaction = Transaction?.Check(false);
QueryTimes++;
WriteSQL(cmd);
using (var da = Factory.CreateDataAdapter())
{
try
{
if (!Opened) Open();
cmd.Connection = Conn;
da.SelectCommand = cmd;
var ds = new DataSet();
BeginTrace();
da.Fill(ds);
return ds;
}
catch (DbException ex)
{
throw OnException(ex, cmd);
}
finally
{
EndTrace(cmd);
AutoClose();
cmd.Parameters.Clear();
}
}
}
private static Regex reg_QueryCount = new Regex(@"^\s*select\s+\*\s+from\s+([\w\W]+)\s*$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
/// <summary>执行SQL查询,返回总记录数</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型,默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public virtual Int64 QueryCount(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
if (sql.Contains(" "))
{
var orderBy = DbBase.CheckOrderClause(ref sql);
var ms = reg_QueryCount.Matches(sql);
if (ms != null && ms.Count > 0)
sql = String.Format("Select Count(*) From {0}", ms[0].Groups[1].Value);
else
sql = String.Format("Select Count(*) From {0}", DbBase.CheckSimpleSQL(sql));
}
else
sql = String.Format("Select Count(*) From {0}", Database.FormatName(sql));
return ExecuteScalar<Int64>(sql, type, ps);
}
/// <summary>执行SQL查询,返回总记录数</summary>
/// <param name="builder">查询生成器</param>
/// <returns>总记录数</returns>
public virtual Int64 QueryCount(SelectBuilder builder)
{
return ExecuteScalar<Int64>(builder.SelectCount().ToString(), CommandType.Text, builder.Parameters.ToArray());
}
/// <summary>快速查询单表记录数,稍有偏差</summary>
/// <param name="tableName"></param>
/// <returns></returns>
public virtual Int64 QueryCountFast(String tableName) { return QueryCount(tableName); }
/// <summary>执行SQL语句,返回受影响的行数</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型,默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public virtual Int32 Execute(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
return Execute(OnCreateCommand(sql, type, ps));
}
/// <summary>执行DbCommand,返回受影响的行数</summary>
/// <param name="cmd">DbCommand</param>
/// <returns></returns>
public virtual Int32 Execute(DbCommand cmd)
{
cmd.Transaction = Transaction?.Check(true);
ExecuteTimes++;
WriteSQL(cmd);
try
{
if (!Opened) Open();
cmd.Connection = Conn;
BeginTrace();
return cmd.ExecuteNonQuery();
}
catch (DbException ex)
{
throw OnException(ex, cmd);
}
finally
{
EndTrace(cmd);
AutoClose();
cmd.Parameters.Clear();
}
}
/// <summary>执行插入语句并返回新增行的自动编号</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型,默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns>新增行的自动编号</returns>
public virtual Int64 InsertAndGetIdentity(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
return Execute(sql, type, ps);
}
/// <summary>执行SQL语句,返回结果中的第一行第一列</summary>
/// <typeparam name="T">返回类型</typeparam>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型,默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public virtual T ExecuteScalar<T>(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
var cmd = OnCreateCommand(sql, type, ps);
cmd.Transaction = Transaction?.Check(false);
return ExecuteScalar<T>(cmd);
}
protected virtual T ExecuteScalar<T>(DbCommand cmd)
{
QueryTimes++;
WriteSQL(cmd);
try
{
BeginTrace();
Object rs = cmd.ExecuteScalar();
if (rs == null || rs == DBNull.Value) return default(T);
if (rs is T) return (T)rs;
return (T)Reflect.ChangeType(rs, typeof(T));
}
catch (DbException ex)
{
throw OnException(ex, cmd);
}
finally
{
EndTrace(cmd);
AutoClose();
cmd.Parameters.Clear();
}
}
/// <summary>获取一个DbCommand。</summary>
/// <remark>
/// 配置了连接,并关联了事务。
/// 连接已打开。
/// 使用完毕后,必须调用AutoClose方法,以使得在非事务及设置了自动关闭的情况下关闭连接
/// </remark>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型,默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public virtual DbCommand CreateCommand(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
var cmd = OnCreateCommand(sql, type, ps);
cmd.Transaction = Transaction?.Check(true);
return cmd;
}
/// <summary>获取一个DbCommand。</summary>
/// <param name="sql">SQL语句</param>
/// <param name="type">命令类型,默认SQL文本</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
protected DbCommand OnCreateCommand(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
var cmd = Factory?.CreateCommand();
if (cmd == null) return null;
if (!Opened) Open();
cmd.Connection = Conn;
cmd.CommandTimeout = Setting.Current.CommandTimeout;
cmd.CommandType = type;
cmd.CommandText = sql;
if (ps != null && ps.Length > 0) cmd.Parameters.AddRange(ps);
return cmd;
}
#endregion
#region 高级
/// <summary>清空数据表,标识归零</summary>
/// <param name="tableName"></param>
/// <returns></returns>
public virtual Int32 Truncate(String tableName)
{
var sql = "Truncate Table {0}".F(Database.FormatName(tableName));
return Execute(sql);
}
#endregion
#region 架构
private DictionaryCache<String, DataTable> _schCache = new DictionaryCache<String, DataTable>(StringComparer.OrdinalIgnoreCase)
{
Expire = 10,
ClearPeriod = 10 * 60,
// 不能异步。否则,修改表结构后,第一次获取会是旧的
Asynchronous = false
};
/// <summary>返回数据源的架构信息。缓存10分钟</summary>
/// <param name="collectionName">指定要返回的架构的名称。</param>
/// <param name="restrictionValues">为请求的架构指定一组限制值。</param>
/// <returns></returns>
public virtual DataTable GetSchema(String collectionName, String[] restrictionValues)
{
// 小心collectionName为空,此时列出所有架构名称
var key = "" + collectionName;
if (restrictionValues != null && restrictionValues.Length > 0) key += "_" + String.Join("_", restrictionValues);
return _schCache.GetItem(key, k => GetSchemaInternal(k, collectionName, restrictionValues));
}
DataTable GetSchemaInternal(String key, String collectionName, String[] restrictionValues)
{
QueryTimes++;
// 如果启用了事务保护,这里要新开一个连接,否则MSSQL里面报错,SQLite不报错,其它数据库未测试
var isTrans = Transaction != null;
DbConnection conn = null;
if (isTrans)
{
conn = Factory.CreateConnection();
checkConnStr();
conn.ConnectionString = ConnectionString;
conn.Open();
}
else
{
if (!Opened) Open();
conn = Conn;
}
try
{
DataTable dt;
var sw = new Stopwatch();
sw.Start();
if (restrictionValues == null || restrictionValues.Length < 1)
{
if (String.IsNullOrEmpty(collectionName))
{
WriteSQL("[" + Database.ConnName + "]GetSchema");
if (conn.State != ConnectionState.Closed) //ahuang 2013。06。25 当数据库连接字符串有误
dt = conn.GetSchema();
else
dt = null;
}
else
{
WriteSQL("[" + Database.ConnName + "]GetSchema(\"" + collectionName + "\")");
if (conn.State != ConnectionState.Closed)
dt = conn.GetSchema(collectionName);
else
dt = null;
}
}
else
{
var sb = new StringBuilder();
foreach (var item in restrictionValues)
{
sb.Append(", ");
if (item == null)
sb.Append("null");
else
sb.AppendFormat("\"{0}\"", item);
}
WriteSQL("[" + Database.ConnName + "]GetSchema(\"" + collectionName + "\"" + sb + ")");
if (conn.State != ConnectionState.Closed)
dt = conn.GetSchema(collectionName, restrictionValues);
else
dt = null;
}
sw.Stop();
// 耗时超过多少秒输出错误日志
if (sw.ElapsedMilliseconds > 1000) DAL.WriteLog("GetSchema耗时 {0:n0}ms", sw.ElapsedMilliseconds);
return dt;
}
catch (DbException ex)
{
throw new XDbSessionException(this, "取得所有表构架出错!", ex);
}
finally
{
if (isTrans)
conn.Close();
else
AutoClose();
}
}
#endregion
#region Sql日志输出
/// <summary>是否输出SQL语句,默认为XCode调试开关XCode.Debug</summary>
public Boolean ShowSQL { get; set; }
static ILog logger;
/// <summary>写入SQL到文本中</summary>
/// <param name="sql"></param>
public void WriteSQL(String sql)
{
if (!ShowSQL) return;
// 如果页面设定有XCode_SQLList列表,则往列表写入SQL语句
var context = HttpContext.Current;
if (context != null)
{
var list = context.Items["XCode_SQLList"] as List<String>;
if (list != null) list.Add(sql);
}
var sqlpath = Setting.Current.SQLPath;
if (String.IsNullOrEmpty(sqlpath))
WriteLog(sql);
else
{
if (logger == null) logger = TextFileLog.Create(sqlpath);
logger.Info(sql);
}
}
private String GetSql(DbCommand cmd)
{
var sql = cmd.CommandText;
var ps = cmd.Parameters;
if (ps != null && ps.Count > 0)
{
var sb = new StringBuilder(64);
sb.Append(sql);
sb.Append(" [");
for (Int32 i = 0; i < ps.Count; i++)
{
if (i > 0) sb.Append(", ");
var v = ps[i].Value;
var sv = "";
if (v is Byte[])
{
var bv = v as Byte[];
if (bv.Length > 8)
sv = String.Format("[{0}]0x{1}...", bv.Length, BitConverter.ToString(bv, 0, 8));
else
sv = String.Format("[{0}]0x{1}", bv.Length, BitConverter.ToString(bv));
}
else if (v is String)
{
sv = v as String;
if (sv.Length > 32) sv = String.Format("[{0}]{1}...", sv.Length, sv.Substring(0, 8));
}
else
sv = "{0}".F(v);
sb.AppendFormat("{0}={1}", ps[i].ParameterName, sv);
}
sb.Append("]");
sql = sb.ToString();
}
return sql;
}
public void WriteSQL(DbCommand cmd)
{
if (!ShowSQL) return;
//var sql = cmd.CommandText;
//if (cmd.CommandType != CommandType.Text) sql = String.Format("[{0}]{1}", cmd.CommandType, sql);
var sql = GetSql(cmd);
WriteSQL(sql);
}
/// <summary>输出日志</summary>
/// <param name="msg"></param>
public static void WriteLog(String msg) { DAL.WriteLog(msg); }
/// <summary>输出日志</summary>
/// <param name="format"></param>
/// <param name="args"></param>
public static void WriteLog(String format, params Object[] args) { DAL.WriteLog(format, args); }
#endregion
#region SQL时间跟踪
private Stopwatch _swSql;
private static HashSet<String> _trace_sqls = new HashSet<String>(StringComparer.OrdinalIgnoreCase);
protected void BeginTrace()
{
if (Setting.Current.TraceSQLTime <= 0) return;
if (_swSql == null) _swSql = new Stopwatch();
if (_swSql.IsRunning) _swSql.Stop();
_swSql.Reset();
_swSql.Start();
}
protected void EndTrace(DbCommand cmd)
{
if (_swSql == null) return;
_swSql.Stop();
if (_swSql.ElapsedMilliseconds < Setting.Current.TraceSQLTime) return;
var sql = GetSql(cmd);
// 同一个SQL只需要报警一次
if (_trace_sqls.Contains(sql)) return;
lock (_trace_sqls)
{
if (_trace_sqls.Contains(sql)) return;
_trace_sqls.Add(sql);
}
XTrace.WriteLine("SQL耗时较长,建议优化 {0:n0}毫秒 {1}", _swSql.ElapsedMilliseconds, sql);
}
#endregion
}
}
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