//一次取一個值的情況，另一種情況與其類似，修改處會標出 #include
#include #include
#include using namespace std;
void mysql_err_function(MYSQL * connection);
void mysql_display(MYSQL * mysql,MYSQL_ROW sqlrow);
int main() {
MYSQL * connection; connection = mysql_init(NULL);
if (mysql_real_connect(connection,"localhost","root","123456","test",0,NULL,0))
{ cout << "Connection to MySQL Server is Succeed..." << endl;
string query = "select * from tmp15"; //getline(cin,query);
int res = mysql_query(connection,query.c_str());
if (res) {
mysql_err_function(connection); }
else {
MYSQL_RES * my_res = mysql_use_result(connection); //將mysql_use_result改為mysql_store_result即可得到另一種情況的結果（其實是相同的...）
if (my_res) {
MYSQL_ROW sqlrow; while ((sqlrow = mysql_fetch_row(my_res)))
{ mysql_display(connection,sqlrow);
}
mysql_free_result(my_res); }
else {
mysql_err_function(connection); }
}
mysql_close(connection); cout << "Connection to MySQL Server is Closed!" << endl;
} else
{ mysql_err_function(connection);
} }
void mysql_err_function(MYSQL * connection)
{ if (mysql_errno(connection))
{ cout << "Error " << mysql_errno(connection) << " : "
<< mysql_error(connection) << endl;
exit(-1); }
}
void mysql_display(MYSQL * mysql,MYSQL_ROW sqlrow) {
for (unsigned int i = 0; i < mysql_field_count(mysql); ++i) {
printf("%s ",sqlrow[i]); //cout << sqlrow[i] << ' '; //不知到為什麼將printf換成cout之後，打印值就會出錯...思考ing...
} cout << endl;
}
1、MYSQL_FIELD *mysql_fetch_field(MYSQL_RES *result); 2、MYSQL_FIELD定義： typedef struct st_mysql_field
{ char *name;
/* Name of column */ char *table;
/* Table of column if column was a field */ char *org_table;
/* Org table name if table was an alias */ char *db;
/* Database for table */ char *def;
/* Default value (set by mysql_list_fields) */ unsigned long length;
/* Width of column */ unsigned long max_length;
/* Max width of selected set */ unsigned int flags;
/* Div flags */ unsigned int decimals;
/* Number of decimals in field */ enum enum_field_types type;
/* Type of field. Se mysql_com.h for types */ } MYSQL_FIELD;
3、IS_NUM宏，若字段類型是數字形式的，則返回真。 if (IS_NUM(mysql_field_ptr -> type)) { cout << "Number" << endl; } 4、MYSQL_FIELD_OFFSET mysql_field_seek(MYSQL_RES * result, MYSQL_FIELD_OFFSET offset); //函數將字段光標設置到給定的偏移量offset,下一次調用mysql_fetch_field將檢索與該偏移量關聯的列的字段定義。如果鑰定位行的開始，則要傳遞一個值為0的offset值。
#include #include
#include #include
using namespace std;
void mysql_err_function(MYSQL * connection); //實現參照上例 void mysql_display(MYSQL * mysql,MYSQL_ROW sqlrow); //實現參照上例
void mysql_display_head(MYSQL_RES * my_res);
int main() {
MYSQL * connection; connection = mysql_init(NULL);
if (mysql_real_connect(connection,"localhost","root","123456","test",0,NULL,0))
{ cout << "Connection to MySQL Server is Succeed..." << endl;
string query = "select * from tmp15"; //getline(cin,query);
int res = mysql_query(connection,query.c_str()); if (res)
{ mysql_err_function(connection);
} else
{ MYSQL_RES * my_res = mysql_use_result(connection);
if (my_res) {
mysql_display_head(my_res);
MYSQL_ROW sqlrow; cout << "Column Details:" << endl;
while ((sqlrow = mysql_fetch_row(my_res))) {
mysql_display(connection,sqlrow); }
mysql_free_result(my_res);
} else
{ mysql_err_function(connection);
} }
mysql_close(connection);
cout << "Connection to MySQL Server is Closed!" << endl; }
else {
mysql_err_function(connection); }
}
void mysql_display_head(MYSQL_RES * my_res) {
MYSQL_FIELD * my_field; cout << "Column Describe:" << endl;
while ((my_field = mysql_fetch_field(my_res))) {
cout << "\tName: " << my_field -> name << endl; cout << "\tType: ";
if (IS_NUM(my_field -> type)) {
cout << "Numeric field"; }
else {
switch(my_field -> type) {
case FIELD_TYPE_VAR_STRING: cout << "Varchar";
break; case FIELD_TYPE_LONG:
cout << "Long"; break;
default: cout << "is " << my_field -> type << ",check in mysql.h";
break; }
} cout << endl;
cout << "\tMax width: " << my_field -> length << endl;
if (my_field -> flags & AUTO_INCREMENT_FLAG) {
cout << "\tAUTO_INCREMENT" << endl; }
cout << endl; }
}
