Question

Hello! Who can give a reference to a working example of using the MySQL database in the ROS Jade project? The simplest example of cpp code mysql_init() and the contents of files cmakelists.txt and package.xml. I've seen similar questions, but there is not complete answer.

Asked by Sergey I. on 2015-10-12 01:17:39 UTC

Answer 1

I did this in Kinetic, but I think it's same in Jade.

Install Ubuntu, ROS and MySQL Server (Please search instruction yourself)
Install libmysqlclient-dev (sudo apt-get install libmysqlclient-dev)
Create catkin package (follow tutorial)
Make sure following code in "package.xml"



<build_depend>cmake_modules</build_depend>
<build_depend>libmysqlclient-dev</build_depend>

<run_depend>cmake_modules</run_depend>
<run_depend>libmysqlclient-dev</run_depend>

<export>
  <cpp lflags="-lmysqlclient"/>
</export>

5. Make sure following code in "CMakeList.txt" of your package, sequence is important.



set(CMAKE_MODULE_PATH ${CMAKE_CURRENT_LIST_DIR}/cmake-modules)
set(EXECUTABLE_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/bin)
set(LIBRARY_OUTPUT_PATH ${PROJECT_SOURCE_DIR}/lib)

find_package(MySqlClient REQUIRED)

include_directories(${MYSQL_INCLUDE_DIRS})

add_definitions(${MYSQL_DEFINITIONS})

target_link_libraries(package_name
   ${catkin_LIBRARIES}
   ${MYSQL_LIBRARIES}
)

6. Create a folder named "cmake-modules" in your package folder. This name is follow 1st line of code in step 5.

7. Copy contents in this URL: https://cmake.org/Wiki/CMakeUserFindMySQL save it to "FindMySqlClient.cmake", in the folder you created in step 6.

8. In your .cpp file, add this include line:



    #include <mysql/mysql.h>

9. Here is a simple sample to get data from sys database.



    MYSQL *connection;  
    MYSQL_RES *result;  
    MYSQL_ROW row; 

    connection = mysql_init(NULL);
    connection = mysql_real_connect(connection, "mysqlserver", "username", "password", "sys", 0, NULL, 0);

    if(mysql_query(connection, "SELECT * FROM sys_config"))  
    {  
        ROS_INFO("Query Error: %s", mysql_error(connection));  
        exit(1);  
    }  
    else  
    {  

        result = mysql_use_result(connection); 
        for(int i=0; i < mysql_field_count(connection); ++i)  
        {
            std::stringstream ss;  
            row = mysql_fetch_row(result);  
            if(row <= 0)  
            {  
                break;  
            }  
            for(int j=0; j < mysql_num_fields(result); ++j)  
            {  
                ss << row[j] << " ";  
            }  
            ROS_INFO("%s", ss.str().c_str());  
        }
        mysql_free_result(result);  
    }

Asked by Wingless Zero on 2016-05-30 20:42:42 UTC

Using the MySQL database in ROS Jade project

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