diff --git a/dbms/include/DB/IO/ReadHelpers.h b/dbms/include/DB/IO/ReadHelpers.h
index 14a2153f090..54c697c83a2 100644
--- a/dbms/include/DB/IO/ReadHelpers.h
+++ b/dbms/include/DB/IO/ReadHelpers.h
@@ -217,6 +217,8 @@ void readEscapedString(String & s, ReadBuffer & buf);
 
 void readQuotedString(String & s, ReadBuffer & buf);
 
+void readDoubleQuotedString(String & s, ReadBuffer & buf);
+
 
 /// в формате YYYY-MM-DD
 inline void readDateText(Yandex::DayNum_t & date, ReadBuffer & buf)
diff --git a/dbms/include/DB/IO/WriteHelpers.h b/dbms/include/DB/IO/WriteHelpers.h
index 0732361ba71..f9064b60bda 100644
--- a/dbms/include/DB/IO/WriteHelpers.h
+++ b/dbms/include/DB/IO/WriteHelpers.h
@@ -93,6 +93,9 @@ inline void writeQuotedString(const String & s, WriteBuffer & buf)
 	writeChar('\'', buf);
 }
 
+/// Совместимо с JSON.
+void writeDoubleQuotedString(const String & s, WriteBuffer & buf);
+
 
 /// в формате YYYY-MM-DD
 inline void writeDateText(Yandex::DayNum_t date, WriteBuffer & buf)
diff --git a/dbms/src/IO/ReadHelpers.cpp b/dbms/src/IO/ReadHelpers.cpp
index dcdf7e267cd..2cd41da171b 100644
--- a/dbms/src/IO/ReadHelpers.cpp
+++ b/dbms/src/IO/ReadHelpers.cpp
@@ -58,12 +58,14 @@ void readEscapedString(String & s, ReadBuffer & buf)
 	}
 }
 
-void readQuotedString(String & s, ReadBuffer & buf)
+
+template <char quote>
+static void readAnyQuotedString(String & s, ReadBuffer & buf)
 {
 	s = "";
 
-	if (buf.eof() || *buf.position() != '\'')
-		throw Exception("Cannot parse quoted string: expected opening single quote",
+	if (buf.eof() || *buf.position() != quote)
+		throw Exception("Cannot parse quoted string: expected opening quote",
 			ErrorCodes::CANNOT_PARSE_QUOTED_STRING);
 	++buf.position();
 
@@ -71,13 +73,13 @@ void readQuotedString(String & s, ReadBuffer & buf)
 	{
 		size_t bytes = 0;
 		for (; buf.position() + bytes != buf.buffer().end(); ++bytes)
-			if (buf.position()[bytes] == '\\' || buf.position()[bytes] == '\'')
+			if (buf.position()[bytes] == '\\' || buf.position()[bytes] == quote)
 				break;
 
 		s.append(buf.position(), bytes);
 		buf.position() += bytes;
 
-		if (*buf.position() == '\'')
+		if (*buf.position() == quote)
 		{
 			++buf.position();
 			return;
@@ -93,8 +95,19 @@ void readQuotedString(String & s, ReadBuffer & buf)
 		}
 	}
 
-	throw Exception("Cannot parse quoted string: expected closing single quote",
+	throw Exception("Cannot parse quoted string: expected closing quote",
 		ErrorCodes::CANNOT_PARSE_QUOTED_STRING);
 }
 
+
+void readQuotedString(String & s, ReadBuffer & buf)
+{
+	readAnyQuotedString<'\''>(s, buf);
+}
+
+void readDoubleQuotedString(String & s, ReadBuffer & buf)
+{
+	readAnyQuotedString<'"'>(s, buf);
+}
+
 }
diff --git a/dbms/src/IO/WriteHelpers.cpp b/dbms/src/IO/WriteHelpers.cpp
index 01573dfff05..1b0a79a2bc6 100644
--- a/dbms/src/IO/WriteHelpers.cpp
+++ b/dbms/src/IO/WriteHelpers.cpp
@@ -37,6 +37,48 @@ void writeEscapedString(const String & s, WriteBuffer & buf)
 				writeChar('\\', buf);
 				writeChar('\'', buf);
 				break;
+			case '\\':
+				writeChar('\\', buf);
+				writeChar('\\', buf);
+				break;
+			default:
+				writeChar(*it, buf);
+		}
+	}
+}
+
+
+void writeDoubleQuotedString(const String & s, WriteBuffer & buf)
+{
+	writeChar('"', buf);
+	for (String::const_iterator it = s.begin(); it != s.end(); ++it)
+	{
+		switch (*it)
+		{
+			case '\b':
+				writeChar('\\', buf);
+				writeChar('b', buf);
+				break;
+			case '\f':
+				writeChar('\\', buf);
+				writeChar('f', buf);
+				break;
+			case '\n':
+				writeChar('\\', buf);
+				writeChar('n', buf);
+				break;
+			case '\r':
+				writeChar('\\', buf);
+				writeChar('r', buf);
+				break;
+			case '\t':
+				writeChar('\\', buf);
+				writeChar('t', buf);
+				break;
+			case '\0':
+				writeChar('\\', buf);
+				writeChar('0', buf);
+				break;
 			case '"':
 				writeChar('\\', buf);
 				writeChar('"', buf);
@@ -49,6 +91,7 @@ void writeEscapedString(const String & s, WriteBuffer & buf)
 				writeChar(*it, buf);
 		}
 	}
+	writeChar('"', buf);
 }
 
 }