Add MarkdownRowOutput format

src/Formats/FormatFactory.cpp

@@ -377,6 +377,7 @@ FormatFactory::FormatFactory()
     registerOutputFormatProcessorODBCDriver2(*this);
     registerOutputFormatProcessorNull(*this);
     registerOutputFormatProcessorMySQLWrite(*this);
+    registerOutputFormatProcessorMarkdown(*this);
 }
 
 FormatFactory & FormatFactory::instance()

src/Formats/FormatFactory.h

@@ -198,6 +198,7 @@ void registerOutputFormatProcessorODBCDriver(FormatFactory & factory);
 void registerOutputFormatProcessorODBCDriver2(FormatFactory & factory);
 void registerOutputFormatProcessorNull(FormatFactory & factory);
 void registerOutputFormatProcessorMySQLWrite(FormatFactory & factory);
+void registerOutputFormatProcessorMarkdown(FormatFactory & factory);
 
 /// Input only formats.
 void registerInputFormatProcessorCapnProto(FormatFactory & factory);

src/Processors/Formats/Impl/MarkdownRowOutputFormat.cpp

+#include <Processors/Formats/Impl/MarkdownRowOutputFormat.h>
+#include <IO/WriteHelpers.h>
+
+namespace DB
+{
+    
+MarkdownRowOutputFormat::MarkdownRowOutputFormat(WriteBuffer & out_, const Block & header_, FormatFactory::WriteCallback callback, const FormatSettings & format_settings_)
+    : IRowOutputFormat(header_, out_, callback), format_settings(format_settings_) {}
+
+void MarkdownRowOutputFormat::writePrefix()
+{
+    auto & header = getPort(PortKind::Main).getHeader();
+    size_t columns = header.columns();
+
+    writeChar('|', out);
+    for (size_t i = 0; i < columns; ++i)
+    {
+        writeEscapedString(header.safeGetByPosition(i).name, out);
+        writeChar('|', out);
+    }
+    writeCString("\n|", out);
+    String format = ":-:|";
+    for (size_t i = 0; i < columns; ++i)
+    {
+        writeString(format, out);
+    }
+    writeChar('\n', out);
+}
+
+void MarkdownRowOutputFormat::writeRowStartDelimiter()
+{
+    writeChar('|', out);
+}
+
+void MarkdownRowOutputFormat::writeFieldDelimiter()
+{
+    writeChar('|', out);
+}
+
+void MarkdownRowOutputFormat::writeRowEndDelimiter()
+{
+    writeCString("|\n", out);
+}
+
+void MarkdownRowOutputFormat::writeField(const IColumn & column, const IDataType & type, size_t row_num)
+{
+    type.serializeAsTextEscaped(column, row_num, out, format_settings);
+}
+
+void registerOutputFormatProcessorMarkdown(FormatFactory & factory)
+{
+    factory.registerOutputFormatProcessor("Markdown", [](
+        WriteBuffer & buf,
+        const Block & sample,
+        FormatFactory::WriteCallback callback,
+        const FormatSettings & settings)
+    {
+        return std::make_shared<MarkdownRowOutputFormat>(buf, sample, callback, settings);
+    });
+}
+
+}
\ No newline at end of file

src/Processors/Formats/Impl/MarkdownRowOutputFormat.h

+#pragma once
+
+#include <Processors/Formats/IRowOutputFormat.h>
+#include <Formats/FormatFactory.h>
+#include <Formats/FormatSettings.h>
+
+namespace DB
+{
+
+class ReadBuffer;
+
+class MarkdownRowOutputFormat : public IRowOutputFormat
+{
+public:
+    MarkdownRowOutputFormat(WriteBuffer & out_, const Block & header_, FormatFactory::WriteCallback callback, const FormatSettings & format_settings_);
+
+    /// Write higher part of markdown table like this:
+    /// |columnName1|columnName2|...|columnNameN|
+    /// |:-:|:-:|...|:-:|
+    void writePrefix() override;
+
+    /// Write '|' before each row
+    void writeRowStartDelimiter() override;
+
+    /// Write '|' between values
+    void writeFieldDelimiter() override;
+
+    /// Write '|\n' after each row
+    void writeRowEndDelimiter() override ;
+
+    void writeField(const IColumn & column, const IDataType & type, size_t row_num) override;
+    String getName() const override { return "MarkdownRowOutputFormat"; }
+
+protected:
+    const FormatSettings format_settings;
+};
+
+
+}

tests/queries/0_stateless/01231_markdown_format.reference

+|id|name|array|
+|:-:|:-:|:-:|
+|1|name1|[1,2,3]|
+|2|name2|[4,5,6]|
+|3|name3|[7,8,9]|

tests/queries/0_stateless/01231_markdown_format.sql

+DROP TABLE IF EXISTS makrdown;
+CREATE TABLE markdown (id UInt32, name String, array Array(Int8)) ENGINE = Memory;
+INSERT INTO markdown VALUES (1, 'name1', [1,2,3]), (2, 'name2', [4,5,6]), (3, 'name3', [7,8,9]);
+
+SELECT * FROM markdown FORMAT Markdown;
+DROP TABLE IF EXISTS markdown