Update readme to show how to build and run hello world

README.md

@@ -22,6 +22,19 @@ C++ client for [ClickHouse](https://clickhouse.com/).
 * Int128
 * UUID
 
+## Requirement
+
+You need gcc cmake libabsl-dev to build this project.
+
+* gcc
+* cmake
+* libabsl-dev
+
+For ubuntu user, you can install them via command:
+```bash
+apt-get install -y cmake gcc libabsl-dev
+```
+
 ## Building
 
 ```sh
@@ -30,6 +43,12 @@ $ cd build
 $ cmake .. [-DBUILD_TESTS=ON]
 $ make
 ```
+if you want to install system lib directory, you may run 
+```bash
+$ sudo make install
+```
+Then the include and lib will install into system /usr/local/{lib,include} directory
+
 
 ## Example
 
@@ -75,3 +94,14 @@ client.Select("SELECT id, name FROM test.numbers", [] (const Block& block)
 /// Delete table.
 client.Execute("DROP TABLE test.numbers");
 ```
+
+If you want to build the example to run hello world, try to build with following command
+```
+cd tests/helloworld
+mkdir build
+cd build
+cmake ..
+make 
+export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/usr/local/lib"
+./helloworld
+```

tests/helloworld/CMakeLists.txt

@@ -0,0 +1,15 @@
+ADD_EXECUTABLE (helloworld
+	main.cpp
+)
+
+TARGET_LINK_LIBRARIES (helloworld
+	clickhouse-cpp-lib
+)
+
+IF (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    # there is a problem with __builtin_mul_overflow call at link time
+    # the error looks like: ... undefined reference to `__muloti4' ... 
+    # caused by clang bug https://bugs.llvm.org/show_bug.cgi?id=16404
+    # explicit linking to compiler-rt allows to workaround the problem
+    set (CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} --rtlib=compiler-rt")
+ENDIF ()

tests/helloworld/main.cpp

@@ -0,0 +1,91 @@
+#include <clickhouse/client.h>
+#include <clickhouse/error_codes.h>
+#include <clickhouse/types/type_parser.h>
+
+#include <stdexcept>
+#include <iostream>
+#include <cmath>
+
+#if defined(_MSC_VER)
+#   pragma warning(disable : 4996)
+#endif
+
+using namespace clickhouse;
+using namespace std;
+
+std::string getEnvOrDefault(const std::string& env, const std::string& default_val)
+{
+    const char* v = std::getenv(env.c_str());
+    return v ? v : default_val;
+}
+
+inline void PrintBlock(const Block& block) {
+    for (Block::Iterator bi(block); bi.IsValid(); bi.Next()) {
+        std::cout << bi.Name() << " ";
+    }
+    std::cout << std::endl;
+
+    for (size_t i = 0; i < block.GetRowCount(); ++i) {
+        std::cout << (*block[0]->As<ColumnUInt64>())[i] << " "
+                  << (*block[1]->As<ColumnString>())[i] << "\n";
+    }
+}
+
+
+inline void GenericExample(Client& client) {
+    /// Create a table.
+    client.Execute("CREATE TEMPORARY TABLE IF NOT EXISTS test_client (id UInt64, name String)");
+
+    /// Insert some values.
+    {
+        Block block;
+
+        auto id = std::make_shared<ColumnUInt64>();
+        id->Append(1);
+        id->Append(7);
+
+        auto name = std::make_shared<ColumnString>();
+        name->Append("one");
+        name->Append("seven");
+
+        block.AppendColumn("id"  , id);
+        block.AppendColumn("name", name);
+
+        client.Insert("test_client", block);
+    }
+
+    /// Select values inserted in the previous step.
+    client.Select("SELECT id, name FROM test_client", [](const Block& block)
+        {
+            PrintBlock(block);
+        }
+    );
+
+    /// Delete table.
+    client.Execute("DROP TEMPORARY TABLE test_client");
+}
+
+
+static void RunTests(Client& client) {
+    GenericExample(client);
+}
+
+int main() {
+    try {
+        {
+            Client client(ClientOptions()
+                            .SetHost(           getEnvOrDefault("CLICKHOUSE_HOST",     "localhost"))
+                            .SetPort( std::stoi(getEnvOrDefault("CLICKHOUSE_PORT",     "9000")))
+                            .SetUser(           getEnvOrDefault("CLICKHOUSE_USER",     "default"))
+                            .SetPassword(       getEnvOrDefault("CLICKHOUSE_PASSWORD", ""))
+                            .SetDefaultDatabase(getEnvOrDefault("CLICKHOUSE_DB",       "default"))
+                            .SetPingBeforeQuery(true));
+            RunTests(client);
+        }
+
+    } catch (const std::exception& e) {
+        std::cerr << "exception : " << e.what() << std::endl;
+    }
+
+    return 0;
+}