• Linux下使用OTL操作mysql数据库


    首先重点推荐介绍otl介绍及用法的文章:http://www.cnblogs.com/fnlingnzb-learner/p/5835560.html

    一、编写代码
    注:以下代码来自OTL示例,略有改动
    #include 
    using namespace std;
    
    #include 
    #include 
    #include 
    
    #define OTL_ODBC // Compile OTL 4.0/ODBC
    // The following #define is required with MyODBC 3.51.11 and higher
    #define OTL_ODBC_SELECT_STM_EXECUTE_BEFORE_DESCRIBE
    #define OTL_ODBC_UNIX // uncomment this line if UnixODBC is used
    #include  // include the OTL 4.0 header file
    otl_connect db; // connect object
    
    void insert()
    // insert rows into table
    {
        otl_stream o(1, // buffer size should be == 1 always on INSERT
                "insert into test_tab values "
                    " (:f1,:f2), "
                    " (:f12,:f22), "
                    " (:f13,:f23), "
                    " (:f14,:f24), "
                    " (:f15,:f25) ",
                // INSERT statement. Multiple sets of values can be used
                // to work around the lack of the bulk interface
                db // connect object
                );
    
        // If the number of rows to be inserted is not known in advance,
        // another stream with the same INSERT can be opened
        otl_stream o2(1, // buffer size should be == 1 always on INSERT
                "insert into test_tab values "
                    " (:f1,:f2)", db // connect object
                );
    
        char tmp[32];
        int i;
        for (i = 1; i <= 100; ++i) {
            sprintf(tmp, "Name%d", i);
            o << i << tmp;
        }
        for (i = 101; i <= 103; ++i) {
            sprintf(tmp, "Name%d", i);
            o2 << i << tmp;
        }
    }
    
    void update(const int af1)
    // insert rows into table
    {
        otl_stream o(1, // buffer size should be == 1 always on UPDATE
                "UPDATE test_tab "
                    "   SET f2=:f2 "
                    " WHERE f1=:f1",
                // UPDATE statement
                db // connect object
                );
        o << "Name changed" << af1;
        o << otl_null() << af1 + 1; // set f2 to NULL
    
    }
    
    void select(const int af1) {
        otl_stream i(50, // buffer size may be > 1
                "select * from test_tab "
                    "where f1>=:f11 "
                    "  and f1<=:f12*2",
                // SELECT statement
                db // connect object
                );
        // create select stream
    
        int f1;
        char f2[31];
    
        i << af1 << af1; // :f11 = af1, :f12 = af1
        while (!i.eof()) { // while not end-of-data
            i >> f1;
            cout << "f1=" << f1 << ", f2=";
            i >> f2;
            if (i.is_null())
                cout << "NULL";
            else
                cout << f2;
            cout << endl;
        }
    
    }
    
    int main() {
        otl_connect::otl_initialize(); // initialize ODBC environment
        try {
            
            // db.rlogon("UID=xuanyuan;PWD=xuanyuan;DSN=examples"); // connect to ODBC
    //其中dsn是odbc连接的名字,不是数据库的名字,otl是通过odbc的名字找到数据库的,  
    //而这个名字对于的配置里面,已经包含了IP,端口等信息,只要你提供用户名和密码就可以访问了  
            //http://jingyan.baidu.com/article/8065f87f38b31423312498e4.html  
      db.rlogon("xuanyuan/xuanyuan@examples"); // connect to ODBC, alternative format of connect string otl_cursor::direct_exec(db, "use examples"); // 此行在原示例代码中没有,必须使用use xxx切换数据库 otl_cursor::direct_exec(db, "drop table test_tab", otl_exception::disabled // disable OTL exceptions ); // drop table otl_cursor::direct_exec(db, "create table test_tab(f1 int, f2 varchar(30)) type=innoDB"); // create table insert(); // insert records into the table update(10); // update records in the table select(8); // select records from the table } catch (otl_exception& p) { // intercept OTL exceptions cerr << p.msg << endl; // print out error message cerr << p.stm_text << endl; // print out SQL that caused the error cerr << p.sqlstate << endl; // print out SQLSTATE message cerr << p.var_info << endl; // print out the variable that caused the error } db.logoff(); // disconnect from ODBC return 0; } 二、编译代码 g++ -o"otl_test2" otl_test2.cpp -lmyodbc3 三、运行程序 otl_test $ ./otl_test2 结果如下: f1=8, f2=Name8 f1=9, f2=Name9 f1=10, f2=Name changed f1=11, f2=NULL f1=12, f2=Name12 f1=13, f2=Name13 f1=14, f2=Name14 f1=15, f2=Name15 f1=16, f2=Name16
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  • 原文地址:https://www.cnblogs.com/fnlingnzb-learner/p/5881927.html
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