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.Threading.Tasks;
using NewLife;
using NewLife.Collections;
using NewLife.Data;
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 Dispose(Boolean disposing)
{
base.Dispose(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.TryDispose();
//Close();
}
catch (ObjectDisposedException) { }
catch (Exception ex)
{
WriteLog("执行" + Database.Type + "的Dispose时出错：" + ex);
}
}
#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 => Database.Type;
///// <summary>工厂</summary>
//private DbProviderFactory Factory => 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; }
///// <summary>数据连接对象。</summary>
//public DbConnection Conn { get; protected set; }
/// <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>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>
/// <param name="sql"></param>
/// <returns></returns>
protected virtual XSqlException OnException(Exception ex, DbCommand cmd, String sql)
{
//if (Transaction == null && Opened) Close(); // 强制关闭数据库
if (sql.IsNullOrEmpty()) sql = GetSql(cmd);
if (ex != null)
return new XSqlException(sql, this, ex);
else
return new XSqlException(sql, this);
}
/// <summary>打开连接并执行操作</summary>
/// <typeparam name="TResult"></typeparam>
/// <param name="callback"></param>
/// <returns></returns>
public virtual TResult Process<TResult>(Func<DbConnection, TResult> callback)
{
using (var conn = Database.OpenConnection())
{
return callback(conn);
}
}
///// <summary>打开连接并执行操作</summary>
///// <typeparam name="TResult"></typeparam>
///// <param name="callback"></param>
///// <returns></returns>
//public virtual async Task<TResult> ProcessAsync<TResult>(Func<DbConnection, Task<TResult>> callback)
//{
// using (var conn = Database.Factory.CreateConnection())
// {
// conn.ConnectionString = Database.ConnectionString;
// await conn.OpenAsync();
// return await callback(conn);
// }
//}
#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(GetType().Name);
try
{
var tr = Transaction;
if (tr == null || tr is DisposeBase db && db.Disposed)
{
tr = new Transaction(this, level);
Transaction = tr;
}
return tr.Begin().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);
}
finally
{
if (tr.Count == 0) Transaction = null;
}
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！");
try
{
tr.Rollback();
}
catch (DbException ex)
{
if (!ignoreException) throw OnException(ex);
}
finally
{
if (tr.Count == 0) Transaction = null;
}
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)
{
using (var cmd = OnCreateCommand(sql, type, ps))
{
return Query(cmd);
}
}
/// <summary>执行DbCommand，返回记录集</summary>
/// <param name="cmd">DbCommand</param>
/// <returns></returns>
public virtual DataSet Query(DbCommand cmd)
{
return Execute(cmd, true, cmd2 =>
{
using (var da = Database.Factory.CreateDataAdapter())
{
da.SelectCommand = cmd2;
var ds = new DataSet();
da.Fill(ds);
return ds;
}
});
}
/// <summary>执行SQL查询，返回记录集</summary>
/// <param name="sql">SQL语句</param>
/// <param name="ps">命令参数</param>
/// <returns></returns>
public virtual DbTable Query(String sql, IDataParameter[] ps)
{
using (var cmd = OnCreateCommand(sql, CommandType.Text, ps))
{
return Execute(cmd, true, cmd2 =>
{
using (var dr = cmd2.ExecuteReader())
{
return OnFill(dr);
}
});
}
}
protected virtual DbTable OnFill(DbDataReader dr)
{
var dt = new DbTable();
dt.Read(dr);
return dt;
}
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) => 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) => 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)
{
using (var cmd = OnCreateCommand(sql, type, ps))
{
return Execute(cmd, false, cmd2 => cmd2.ExecuteNonQuery());
}
}
/// <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) => Execute(cmd, false, cmd2 => cmd2.ExecuteNonQuery());
public virtual T Execute<T>(DbCommand cmd, Boolean query, Func<DbCommand, T> callback)
{
Transaction?.Check(cmd, !query);
if (query)
QueryTimes++;
else
ExecuteTimes++;
var text = WriteSQL(cmd);
return Process(conn =>
{
//DbConnection conn = null;
try
{
//if (cmd.Connection == null) cmd.Connection = conn = Database.Pool.Get();
if (cmd.Connection == null) cmd.Connection = conn;
BeginTrace();
return callback(cmd);
}
catch (DbException ex)
{
throw OnException(ex, cmd, text);
}
finally
{
//if (conn != null) Database.Pool.Put(conn);
EndTrace(cmd, text);
}
});
}
/// <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);
using (var cmd = OnCreateCommand(sql, type, ps))
{
//Transaction?.Check(cmd, true);
//return ExecuteScalar<Int64>(cmd);
return Execute(cmd, false, cmd2 =>
{
var rs = cmd.ExecuteScalar();
if (rs == null || rs == DBNull.Value) return 0;
return Reflect.ChangeType<Int64>(rs);
});
}
}
/// <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)
{
using (var cmd = OnCreateCommand(sql, type, ps))
{
//return ExecuteScalar<T>(cmd);
return Execute(cmd, true, cmd2 =>
{
var 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));
});
}
}
//protected virtual T ExecuteScalar<T>(DbCommand cmd)
//{
// Transaction?.Check(cmd, false);
// QueryTimes++;
// WriteSQL(cmd);
// var conn = Database.Pool.Get();
// try
// {
// if (cmd.Connection == null) cmd.Connection = conn;
// BeginTrace();
// var 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
// {
// Database.Pool.Put(conn);
// 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);
Transaction?.Check(cmd, 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 virtual DbCommand OnCreateCommand(String sql, CommandType type = CommandType.Text, params IDataParameter[] ps)
{
var cmd = Database.Factory?.CreateCommand();
if (cmd == null) return null;
//if (!Opened) Open();
//cmd.Connection = Conn;
cmd.CommandType = type;
cmd.CommandText = sql;
if (ps != null && ps.Length > 0) cmd.Parameters.AddRange(ps);
var timeout = Setting.Current.CommandTimeout;
if (timeout > 0) cmd.CommandTimeout = timeout;
return cmd;
}
#endregion
#region 批量操作
/// <summary>批量插入</summary>
/// <param name="tableName">表名</param>
/// <param name="columns">要插入的字段，默认所有字段</param>
/// <param name="list">实体列表</param>
/// <returns></returns>
public virtual Int32 Insert(String tableName, IDataColumn[] columns, IEnumerable<IIndexAccessor> list) => throw new NotSupportedException();
/// <summary>批量更新</summary>
/// <param name="tableName">表名</param>
/// <param name="columns">要更新的字段，默认所有字段</param>
/// <param name="updateColumns">要更新的字段，默认脏数据</param>
/// <param name="addColumns">要累加更新的字段，默认累加</param>
/// <param name="list">实体列表</param>
/// <returns></returns>
public virtual Int32 Update(String tableName, IDataColumn[] columns, ICollection<String> updateColumns, ICollection<String> addColumns, IEnumerable<IIndexAccessor> list) => throw new NotSupportedException();
/// <summary>批量插入或更新</summary>
/// <param name="tableName">表名</param>
/// <param name="columns">要插入的字段，默认所有字段</param>
/// <param name="updateColumns">主键已存在时，要更新的字段</param>
/// <param name="addColumns">主键已存在时，要累加更新的字段</param>
/// <param name="list">实体列表</param>
/// <returns></returns>
public virtual Int32 Upsert(String tableName, IDataColumn[] columns, ICollection<String> updateColumns, ICollection<String> addColumns, IEnumerable<IIndexAccessor> list) => throw new NotSupportedException();
#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
/// <summary>返回数据源的架构信息。缓存10分钟</summary>
/// <param name="conn">连接</param>
/// <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(DbConnection conn, 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);
var db = Database as DbBase;
var dt = db._SchemaCache[key];
if (dt == null)
{
/*
* TODO: Bug
* sqlserver切换到master库时,仍然使用Process去获取DbConnection，然而此时DataBase对象为连接字符串中的数据库
* 这里不知道是应该在RemoteDb的OpenDatabase方法（改变DataBase对象）抑或是修改这里的Process方法
*/
if (conn != null)
dt = GetSchemaInternal(conn, key, collectionName, restrictionValues);
else
dt = Process(conn2 => GetSchemaInternal(conn2, key, collectionName, restrictionValues));
db._SchemaCache[key] = dt;
}
return dt;
}
DataTable GetSchemaInternal(DbConnection conn, String key, String collectionName, String[] restrictionValues)
{
QueryTimes++;
DataTable dt = null;
var sw = Stopwatch.StartNew();
if (restrictionValues == null || restrictionValues.Length < 1)
{
if (String.IsNullOrEmpty(collectionName))
{
WriteSQL("[" + Database.ConnName + "]GetSchema");
dt = conn.GetSchema();
}
else
{
WriteSQL("[" + Database.ConnName + "]GetSchema(\"" + collectionName + "\")");
dt = conn.GetSchema(collectionName);
}
}
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 + ")");
dt = conn.GetSchema(collectionName, restrictionValues);
}
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;
}
#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 (sql.IsNullOrEmpty()) return;
// 如果页面设定有XCode_SQLList列表，则往列表写入SQL语句
DAL.LocalFilter?.Invoke(sql);
if (!ShowSQL) return;
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 max = (Database as DbBase).SQLMaxLength;
try
{
var sql = cmd.CommandText;
var ps = cmd.Parameters;
if (ps != null && ps.Count > 0)
{
var sb = Pool.StringBuilder.Get();
sb.Append(sql);
sb.Append(" [");
for (var 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 str && str.Length > 64)
sv = String.Format("[{0}]{1}...", str.Length, str.Substring(0, 64));
else
sv = "{0}".F(v);
sb.AppendFormat("{0}={1}", ps[i].ParameterName, sv);
}
sb.Append("]");
sql = sb.Put(true);
}
// 截断超长字符串
if (max > 0)
{
if (sql.Length > max && sql.StartsWithIgnoreCase("Insert")) sql = sql.Substring(0, max / 2) + "..." + sql.Substring(sql.Length - max / 2);
}
return sql;
}
catch { return null; }
}
public String WriteSQL(DbCommand cmd)
{
// 如果页面设定有XCode_SQLList列表，则往列表写入SQL语句
if (!ShowSQL && DAL.LocalFilter == null) return null;
var sql = GetSql(cmd);
WriteSQL(sql);
return sql;
}
/// <summary>输出日志</summary>
/// <param name="format"></param>
/// <param name="args"></param>
public static void WriteLog(String format, params Object[] args) => XTrace.WriteLine(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 ((Database as DbBase).TraceSQLTime <= 0) return;
if (_swSql == null) _swSql = new Stopwatch();
if (_swSql.IsRunning) _swSql.Stop();
_swSql.Reset();
_swSql.Start();
}
protected void EndTrace(DbCommand cmd, String sql = null)
{
if (_swSql == null) return;
_swSql.Stop();
if (_swSql.ElapsedMilliseconds < (Database as DbBase).TraceSQLTime) return;
if (sql.IsNullOrEmpty()) sql = GetSql(cmd);
if (sql.IsNullOrEmpty()) return;
// 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;
if (_trace_sqls.Count >= 1000) _trace_sqls.Clear();
_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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