Add NoBackslashEscapes option. Fixes #701

Author: bgrainger

docs/content/connection-options.md

@@ -344,6 +344,11 @@ These are the other options that MySqlConnector supports. They are set to sensib
         <dd>Servers are tried in ascending order of number of currently-open connections in this connection pool. Requires <code>Pooling=True</code>.
       </dl>
   </tr>
+  <tr>
+    <td>No Backslash Escapes, NoBackslashEscapes</td>
+    <td>false</td>
+    <td>If <code>true</code>, backslashes are not escaped in string parameters. Set this to <code>true</code> if the server’s SQL mode includes <a href="https://dev.mysql.com/doc/refman/8.0/en/sql-mode.html#sqlmode_no_backslash_escapes"><code>NO_BACKSLASH_ESCAPES</code></a>.</td>
+  </tr>
   <tr>
     <td>Old Guids, OldGuids</td>
     <td>false</td>

src/MySqlConnector/Core/ConnectionSettings.cs

@@ -84,6 +84,7 @@ public ConnectionSettings(MySqlConnectionStringBuilder csb)
 			InteractiveSession = csb.InteractiveSession;
 			GuidFormat = GetEffectiveGuidFormat(csb.GuidFormat, csb.OldGuids);
 			Keepalive = csb.Keepalive;
+			NoBackslashEscapes = csb.NoBackslashEscapes;
 			PersistSecurityInfo = csb.PersistSecurityInfo;
 			ServerRsaPublicKeyFile = csb.ServerRsaPublicKeyFile;
 			ServerSPN = csb.ServerSPN;
@@ -167,6 +168,7 @@ private static MySqlGuidFormat GetEffectiveGuidFormat(MySqlGuidFormat guidFormat
 		public bool IgnorePrepare { get; }
 		public bool InteractiveSession { get; }
 		public uint Keepalive { get; }
+		public bool NoBackslashEscapes { get; }
 		public bool PersistSecurityInfo { get; }
 		public string ServerRsaPublicKeyFile { get; }
 		public string ServerSPN { get; }

src/MySqlConnector/Core/IMySqlCommand.cs

@@ -36,6 +36,8 @@ public static StatementPreparerOptions CreateStatementPreparerOptions(this IMySq
 				statementPreparerOptions |= StatementPreparerOptions.DateTimeLocal;
 			if (command.CommandType == CommandType.StoredProcedure)
 				statementPreparerOptions |= StatementPreparerOptions.AllowOutputParameters;
+			if (connection.NoBackslashEscapes)
+				statementPreparerOptions |= StatementPreparerOptions.NoBackslashEscapes;
 
 			statementPreparerOptions |= connection.GuidFormat switch
 			{

src/MySqlConnector/MySql.Data.MySqlClient/MySqlConnection.cs

@@ -548,6 +548,7 @@ internal async Task<CachedProcedure> GetCachedProcedure(IOBehavior ioBehavior, s
 		internal bool IgnoreCommandTransaction => m_connectionSettings.IgnoreCommandTransaction || m_enlistedTransaction is StandardEnlistedTransaction;
 #endif
 		internal bool IgnorePrepare => m_connectionSettings.IgnorePrepare;
+		internal bool NoBackslashEscapes => m_connectionSettings.NoBackslashEscapes;
 		internal bool TreatTinyAsBoolean => m_connectionSettings.TreatTinyAsBoolean;
 		internal IOBehavior AsyncIOBehavior => GetConnectionSettings().ForceSynchronous ? IOBehavior.Synchronous : IOBehavior.Asynchronous;
 

src/MySqlConnector/MySql.Data.MySqlClient/MySqlConnectionStringBuilder.cs

@@ -269,6 +269,12 @@ public uint Keepalive
 			set => MySqlConnectionStringOption.Keepalive.SetValue(this, value);
 		}
 
+		public bool NoBackslashEscapes
+		{
+			get => MySqlConnectionStringOption.NoBackslashEscapes.GetValue(this);
+			set => MySqlConnectionStringOption.NoBackslashEscapes.SetValue(this, value);
+		}
+
 		public bool OldGuids
 		{
 			get => MySqlConnectionStringOption.OldGuids.GetValue(this);
@@ -409,6 +415,7 @@ internal abstract class MySqlConnectionStringOption
 		public static readonly MySqlConnectionStringOption<bool> IgnorePrepare;
 		public static readonly MySqlConnectionStringOption<bool> InteractiveSession;
 		public static readonly MySqlConnectionStringOption<uint> Keepalive;
+		public static readonly MySqlConnectionStringOption<bool> NoBackslashEscapes;
 		public static readonly MySqlConnectionStringOption<bool> OldGuids;
 		public static readonly MySqlConnectionStringOption<bool> PersistSecurityInfo;
 		public static readonly MySqlConnectionStringOption<string> ServerRsaPublicKeyFile;
@@ -608,6 +615,10 @@ static MySqlConnectionStringOption()
 				keys: new[] { "Keep Alive", "Keepalive" },
 				defaultValue: 0u));
 
+			AddOption(NoBackslashEscapes = new MySqlConnectionStringOption<bool>(
+				keys: new[] { "No Backslash Escapes", "NoBackslashEscapes" },
+				defaultValue: false));
+
 			AddOption(OldGuids = new MySqlConnectionStringOption<bool>(
 				keys: new[] { "Old Guids", "OldGuids" },
 				defaultValue: false));

tests/MySqlConnector.Tests/MySqlConnectionStringBuilderTests.cs

@@ -50,6 +50,9 @@ public void Defaults()
 			Assert.Equal(0u, csb.MinimumPoolSize);
 			Assert.Equal("", csb.Password);
 			Assert.Equal("MYSQL", csb.PipeName);
+#if !BASELINE
+			Assert.False(csb.NoBackslashEscapes);
+#endif
 			Assert.False(csb.OldGuids);
 			Assert.False(csb.PersistSecurityInfo);
 			Assert.True(csb.Pooling);
@@ -107,6 +110,7 @@ public void ParseConnectionString()
 					"server rsa public key file=rsa.pem;" +
 					"load balance=random;" +
 					"guidformat=timeswapbinary16;" +
+					"nobackslashescapes=true;" +
 					"server spn=mariadb/[email protected];" +
 					"use xa transactions=false;" +
 #endif
@@ -162,6 +166,7 @@ public void ParseConnectionString()
 			Assert.Equal("rsa.pem", csb.ServerRsaPublicKeyFile);
 			Assert.Equal(MySqlLoadBalance.Random, csb.LoadBalance);
 			Assert.Equal(MySqlGuidFormat.TimeSwapBinary16, csb.GuidFormat);
+			Assert.True(csb.NoBackslashEscapes);
 			Assert.Equal("mariadb/[email protected]", csb.ServerSPN);
 			Assert.False(csb.UseXaTransactions);
 #endif

tests/SideBySide/QueryTests.cs

@@ -1071,6 +1071,28 @@ public void CommandBehaviorSingleRow()
 			Assert.False(reader.Read());
 		}
 
+#if !BASELINE
+		[Fact]
+		public void NoBackslashEscapes()
+		{
+			var csb = AppConfig.CreateConnectionStringBuilder();
+			csb.NoBackslashEscapes = true;
+			using var connection = new MySqlConnection(csb.ConnectionString);
+			connection.Open();
+			connection.Execute("SET @@sql_mode = CONCAT(@@sql_mode, ',NO_BACKSLASH_ESCAPES');");
+			var value = "\\'\"";
+			using var cmd = new MySqlCommand("SELECT @param;", connection)
+			{
+				Parameters =
+				{
+					new MySqlParameter("@param", value),
+				},
+			};
+			var result = cmd.ExecuteScalar();
+			Assert.Equal(value, result);
+		}
+#endif
+
 		class BoolTest
 		{
 			public int Id { get; set; }