C ++ and C # simple sample code for accessing MySQL

Paste the sample code. It is very suitable for beginners.

1) C # access MySQL

Using system; using system. collections. generic; using system. text; using MySQL. data. mysqlclient; using system. data; using system. data. common; namespace sybaseutiltest {class program {// http://bugs.mysql.com/47422, interested friends, you can see how this bug is going static void testdataadapter () {try {mysqlclientfactory factory = mysqlclientfactory. instance; dbconnection conn = factory. createconnection (); Conn. connectionstring = string. format ("Server = {0}; user id = {1}; Password = {2}; database = {3}; Port = {4}; pooling = false ", "localhost", "root", "passwd", "test", 3306); Conn. open (); dbdataadapter da = factory. createdataadapter (); DA. selectcommand = Conn. createcommand (); DA. selectcommand. commandtext = "select * From t12345"; DA. deletecommand = Conn. createcommand (); DA. deletecommand. commandtext = "delete from t12345 where id = @ ID"; dbparameter Param = factory. createparameter (); Param. parametername = "@ ID"; Param. dbtype = dbtype. int32; Param. sourcecolumn = "ID"; Param. sourceversion = datarowversion. current; DA. deletecommand. parameters. add (PARAM); DA. deletecommand. updatedrowsource = updaterowsource. none; datatable dt = new datatable ("t12345"); DA. fill (DT); int Index = 0; foreach (datarow o in DT. rows) {If (O ["ID"]. equals (4) {console. writeline (string. format ("Index = {0}, to delete id = 4, col2 = {1}", index, O ["col2"]); break ;} index ++;} DT. rows [Index]. delete (); DA. update (DT); DT. acceptchanges (); DA. dispose (); Conn. close ();} catch (exception ex) {console. writeline (ex. source + "" + ex. message + "" + ex. stacktrace) ;}} static void main (string [] ARGs) {testdataadapter ();}}}

2) C ++ access (directly call the C-API)

#include <iostream>#include <windows.h>#include <mysql.h>#include <string>static const char host[32] = "localhost";static const char user[32] = "test";static const char passwd[32] = "passwd";static const char db[32] = "test";/**mysql> select * from t;+----+| id |+----+|  1 |+----+1 row in set (0.00 sec)mysql> delimiter //mysql> create procedure get_t(in t1 int)    -> begin    -> select id from t where id=t1;    -> end    -> //Query OK, 0 rows affected (0.05 sec)mysql> call get_t(1);    -> //+----+| id |+----+|  1 |+----+1 row in set (0.00 sec)Query OK, 0 rows affected (0.00 sec)*/void test_more_results(MYSQL* h){    char str[512] = "insert into test_num values(101);insert into test_num values(122);commit;";    int r = mysql_real_query(h, str, strlen(str));    if (r)    {        const char * error = mysql_error(h);        std::cout<<"*** Connection Error " << error << std::endl;    }    do    {        MYSQL_RES* res = mysql_store_result(h);        mysql_free_result(res);    }    while ( (0 == mysql_next_result(h)) );   }void test_proc_stmt(MYSQL* h){    MYSQL* mysql_ = h;    MYSQL_BIND          bind;    MYSQL_BIND          obind[1];    // test_more_results(mysql_);    MYSQL_STMT *hStmt = mysql_stmt_init(mysql_);    my_bool true_value= 1;    mysql_stmt_attr_set(hStmt, STMT_ATTR_UPDATE_MAX_LENGTH, (void*) &true_value);       char sql[] = "call get_t(?)";    //char sql[] = "select id from t where id=?";    if (mysql_stmt_prepare(hStmt, sql, strlen(sql)))    {        std::cout<<__LINE__<<": stmt prepare error:  "<< (mysql_stmt_error(hStmt))<<std::endl;        mysql_stmt_reset(hStmt);        if (mysql_stmt_prepare(hStmt, sql, strlen(sql)))        {            std::cout<<__LINE__<<": stmt prepare error:  "<< (mysql_stmt_error(hStmt))<<std::endl;            mysql_close(mysql_);            exit( -1);        }    }    int id = 1;    unsigned long id_len = 0;    memset(&bind, 0, sizeof(bind));    bind.buffer_type = FIELD_TYPE_LONG;    bind.buffer = (void*)&id;    bind.is_unsigned = true;    bind.length = &id_len;    // bind[0].buffer_length = sizeof(id);    // bind[0].is_null = 0;       if (mysql_stmt_bind_param(hStmt,(MYSQL_BIND*)(&bind)) != 0)    {        std::cout<<__LINE__<<": stmt prepare error:  "<< (mysql_stmt_error(hStmt))<<std::endl;        mysql_close(mysql_);        exit( -1);    }    if (mysql_stmt_execute(hStmt) != 0)    {        std::cout<<__LINE__<<": stmt prepare error:  "<< (mysql_stmt_error(hStmt))<<std::endl;        mysql_close(mysql_);        exit( -1);    }    int t2;    memset(obind, 0, sizeof(obind));    obind[0].buffer_type= MYSQL_TYPE_LONG;    obind[0].buffer= (char *)&t2;    obind[0].buffer_length = sizeof(t2);       if (mysql_stmt_bind_result(hStmt, (MYSQL_BIND*)&obind[0]) != 0)    {        std::cout<<__LINE__<<": stmt prepare error:  "<< (mysql_stmt_error(hStmt))<<std::endl;        mysql_close(mysql_);        exit( -1);    }    if ( mysql_stmt_store_result(hStmt) != 0 )    {        std::cout<<__LINE__<<": stmt prepare error:  "<< (mysql_stmt_error(hStmt))<<std::endl;        mysql_close(mysql_);        exit( -1);    }          int rows = mysql_stmt_num_rows(hStmt);    for (int i=0; i<rows; i++)    {        if (mysql_stmt_fetch(hStmt) == 0)        {            std::cout<<"id = "<<t2<<std::endl;        }    }    mysql_stmt_free_result(hStmt);    mysql_stmt_close(hStmt);}//// Just for demo only.//int main(){    MYSQL*              mysql_ = NULL;    MYSQL_RES*          result_ = NULL;    MYSQL_ROW           row_;    mysql_ = mysql_init(mysql_);    // if (mysql_real_connect(mysql_, host, user, passwd, db, 3306, NULL, CLIENT_MULTI_STATEMENTS) == NULL)    if (mysql_real_connect(mysql_, host, user, passwd, db, 3306, NULL, CLIENT_MULTI_STATEMENTS) == NULL)    {        const char * error = mysql_error(mysql_);        std::cout<<"*** Connection Error " << error << std::endl;        return -1;    }    mysql_autocommit(mysql_, false);    std::string encodeStr = "set names 'gbk'";    mysql_real_query(mysql_, encodeStr.c_str(), encodeStr.size());       /*    const char* tmpTableName = "t";  // assume you are querying the table 't'    char str[512];    int cnt = 0;    sprintf(str,"select count(*) as cnt from %s", tmpTableName);    mysql_real_query(mysql_, str, strlen(str));    result_ = mysql_store_result(mysql_);    while (row_ = mysql_fetch_row(result_))    {        // get the field value        if (row_[0])        {            std::cout<<"count = "<<row_[0]<<std::endl;            // convert it into int            cnt = atoi(row_[0]);            std::cout<<"cnt value = "<<row_[0]<<std::endl;        }    }    mysql_free_result(result_);    test_more_results();    */    test_proc_stmt(mysql_);       do    {        MYSQL_RES* res = mysql_store_result(mysql_);        mysql_free_result(res);    }    while ( (0 == mysql_next_result(mysql_)) );       test_proc_stmt(mysql_);    mysql_close(mysql_);    return 0;}