apewer-dotnet/Apewer.Source/Externals/MySql.Data-6.10.9/MySqlClient/NetStandard_2.0/MySqlConnection.cs

#if MYSQL_6_10

// Copyright © 2004, 2018, Oracle and/or its affiliates. All rights reserved.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most 
// MySQL Connectors. There are special exceptions to the terms and 
// conditions of the GPLv2 as it is applied to this software, see the 
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify 
// it under the terms of the GNU General Public License as published 
// by the Free Software Foundation; version 2 of the License.
//
// This program is distributed in the hope that it will be useful, but 
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
// for more details.
//
// You should have received a copy of the GNU General Public License along 
// with this program; if not, write to the Free Software Foundation, Inc., 
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA


using System;
using System.ComponentModel;
using System.Data;
using System.Data.Common;
using System.Security;
using System.Drawing;
using System.Security.Permissions;
using System.Transactions;

namespace Externals.MySql.Data.MySqlClient
{
    [DesignerCategory("Code")]
    [ToolboxItem(true)]
    internal sealed partial class MySqlConnection : DbConnection, ICloneable
    {
        /// <summary>
        /// Returns schema information for the data source of this <see cref="DbConnection"/>. 
        /// </summary>
        /// <returns>A <see cref="DataTable"/> that contains schema information. </returns>
        public override DataTable GetSchema()
        {
            return GetSchema(null);
        }

        /// <summary>
        /// Returns schema information for the data source of this 
        /// <see cref="DbConnection"/> using the specified string for the schema name. 
        /// </summary>
        /// <param name="collectionName">Specifies the name of the schema to return. </param>
        /// <returns>A <see cref="DataTable"/> that contains schema information. </returns>
        public override DataTable GetSchema(string collectionName)
        {
            if (collectionName == null)
                collectionName = SchemaProvider.MetaCollection;

            return GetSchema(collectionName, null);
        }

        /// <summary>
        /// Returns schema information for the data source of this <see cref="DbConnection"/>
        /// using the specified string for the schema name and the specified string array 
        /// for the restriction values. 
        /// </summary>
        /// <param name="collectionName">Specifies the name of the schema to return.</param>
        /// <param name="restrictionValues">Specifies a set of restriction values for the requested schema.</param>
        /// <returns>A <see cref="DataTable"/> that contains schema information.</returns>
        public override DataTable GetSchema(string collectionName, string[] restrictionValues)
        {
            if (collectionName == null)
                collectionName = SchemaProvider.MetaCollection;

            string[] restrictions = _schemaProvider.CleanRestrictions(restrictionValues);
            MySqlSchemaCollection c = _schemaProvider.GetSchema(collectionName, restrictions);
            return c.AsDataTable();
        }

        /// <summary>
        /// Enlists in the specified transaction. 
        /// </summary>
        /// <param name="transaction">
        /// A reference to an existing <see cref="System.Transactions.Transaction"/> in which to enlist.
        /// </param>
        public override void EnlistTransaction(Transaction transaction)
        {
            // enlisting in the null transaction is a noop
            if (transaction == null)
                return;

            // guard against trying to enlist in more than one transaction
            if (driver.currentTransaction != null)
            {
                if (driver.currentTransaction.BaseTransaction == transaction)
                    return;

                Throw(new MySqlException("Already enlisted"));
            }

            // now see if we need to swap out drivers.  We would need to do this since
            // we have to make sure all ops for a given transaction are done on the
            // same physical connection.
            Driver existingDriver = DriverTransactionManager.GetDriverInTransaction(transaction);
            if (existingDriver != null)
            {
                // we can't allow more than one driver to contribute to the same connection
                if (existingDriver.IsInActiveUse)
                    Throw(new NotSupportedException(Resources.MultipleConnectionsInTransactionNotSupported));

                // there is an existing driver and it's not being currently used.
                // now we need to see if it is using the same connection string
                string text1 = existingDriver.Settings.ConnectionString;
                string text2 = Settings.ConnectionString;
                if (String.Compare(text1, text2, true) != 0)
                    Throw(new NotSupportedException(Resources.MultipleConnectionsInTransactionNotSupported));

                // close existing driver
                // set this new driver as our existing driver
                CloseFully();
                driver = existingDriver;
            }

            if (driver.currentTransaction == null)
            {
                MySqlPromotableTransaction t = new MySqlPromotableTransaction(this, transaction);
                if (!transaction.EnlistPromotableSinglePhase(t))
                    Throw(new NotSupportedException(Resources.DistributedTxnNotSupported));

                driver.currentTransaction = t;
                DriverTransactionManager.SetDriverInTransaction(driver);
                driver.IsInActiveUse = true;
            }
        }

        void AssertPermissions()
        {
            // Security Asserts can only be done when the assemblies 
            // are put in the GAC as documented in 
            // http://msdn.microsoft.com/en-us/library/ff648665.aspx
            if (this.Settings.IncludeSecurityAsserts)
            {
                PermissionSet set = new PermissionSet(PermissionState.None);
                set.AddPermission(new MySqlClientPermission(ConnectionString));
                set.Demand();
                MySqlSecurityPermission.CreatePermissionSet(true).Assert();
            }
        }

        /// <summary>
        /// Creates a new MySqlConnection object with the exact same ConnectionString value
        /// </summary>
        /// <returns>A cloned MySqlConnection object</returns>
        public object Clone()
        {
            MySqlConnection clone = new MySqlConnection();
            string connectionString = Settings.ConnectionString;
            if (connectionString != null)
                clone.ConnectionString = connectionString;
            return clone;
        }
    }
}

#endif