C++下使用MySQL数据库

转载地址:http://curran.blog.51cto.com/2788306/533169

今天给大家演示在linux下如果用C++操作mysql

1:安装MySQL

挂载光盘：

mkdir /cdrom
mount /dev/hdc /cdrom
cd /cdrom/Server
rpm -ivh perl-DBI-1.52-2.el5.i386.rpm
rpm -ivh mysql-5.0.45-7.el5.i386.rpm mysql-bench-5.0.45-7.el5.i386.rpm mysql-devel-5.0.45-7.el5.i386.rpm
rpm -ivh perl-DBD-MySQL-3.0007-2.el5.i386.rpm
rpm -ivh mysql-server-5.0.45-7.el5.i386.rpm mysql-test-5.0.45-7.el5.i386.rpm

查看mysql服务状态：

service mysqld status

启动服务：

service mysqld start

连接数据库：

mysql

2：安装gcc工具包

rpm -ivh gcc* --force --nodeps 强制安装

3：进入mysql

create table t1 (id int,name varchar(30));

t1表插入数据：

1.cpp
#include
#include
#include
using namespace std;
main()
{
MYSQL mysql;
mysql_init(&mysql);
mysql_real_connect(&mysql, "localhost", "root", "root", "test", 3306, NULL, 0);
string sql = "insert into t1 (id, name) values (1, 'java1');";
mysql_query(&mysql, sql.c_str());
mysql_close(&mysql);
}
g++ -o 1.out 1.cpp -lmysqlclient -I/usr/include/mysql/ -L/usr/lib/mysql

更新mysql数据；

1.cpp
#include
#include
#include

using namespace std;

main()
{
MYSQL mysql;
mysql_init(&mysql);
mysql_real_connect(&mysql, "localhost", "root", "root", "test", 3306, NULL, 0);
string sql = "insert into t1 (id,name) values (2, 'java2'),(3, 'java3');";
mysql_query(&mysql, sql.c_str());
sql = "update t1 set name = 'java33' where id = 3;";
mysql_query(&mysql, sql.c_str());
mysql_close（&mysql);
}
g++ -o 1.out 1.cpp -lmysqlclient -I/usr/include/mysql/ -L/usr/lib/mysql
./1.out

mysql 存储过程：

mysql>delimiter //
>create procedure p01()
>begin
>insert into t1 (id,name) values (66, 'java66');
>end;
>//

应用存储过程：

mysql>delimiter //
>create procedure p01()
>begin
>insert into t1 (id,name) values (66, 'java66');
>end;
>//

触发器：
新建t2表：

mysql>delimiter //
>create trigger tr1 after insert on t1 for each row
>begin
>insert into t2 (id,name) values (new.id,new.name);
>end;
>//
>delete from t1 where id = 66;
>//
>delimeter ;

vi 3.cpp
#include
#include
#include

using namespace std;

main()
{
MYSQL mysql;
mysql_init(&mysql);
mysql_real_connect(&mysql, "localhost", "root", "root", 3306, NULL, 0);
string sql = "call p01();";
mysql_query(&mysql, sql.c_str());
mysql_close(&mysql);
}

g++ -o 3.out 3.cpp -lmysqlclient -I/usr/include/mysql/ -L/usr/lib/mysql
./3.out

mysql>delimeter ;
>select * from t1;
>select * from t2;
>存在数据(66, 'java66')

查看表中数据的总数：

vi 4.cpp
#include
#include
#include

using namespace std;

main()
{
MYSQL mysql;
MYSQL_RES *result = NULL;
mysql_init(&mysql);
mysql_real_connect(&mysql, "localhost", "root", "root", "test", 3306, NULL, 0);
string sql = "select id,name from t1;";
mysql_query(&mysql, sql.c_str());
result = mysql_store_result(&mysql);
int rowcount = mysql_num_rows(result);
cout << rowcount << endl;
mysql_close(&mysql);
}

g++ -o 4.out 4.cpp -lmysqlclient -I/usr/include/mysql/ -L/usr/lib/mysql
./4.out

查处字段的总数:

vi 5.cpp
#include
#include
#include

using namespace std;

main()
{
MYSQL mysql;
MYSQL_RES *result = NULL;
mysql_init(&mysql);
mysql_real_connect(&mysql, "localhost", "root", "root", 3306, NULL, 0);
string str = "select id,name from t1;";
mysql_query(&mysql, sql.c_str());
result = mysql_store_result(&mysql);
int rowcount = mysql_num_rows(result);
cout << rowcount << endl;
int fieldcount = mysql_num_fields(result);
cout << fieldcount << endl;
mysql_close(&mysql);
}

g++ -o 5.out 5.cpp -lmysqlclient -I/usr/include/mysql/ -L/usr/lib/mysql
./5.out

列出具体字段名：

vi 6.cpp
#include
#include
#include

using namespace std;

main()
{
MYSQL mysql;
MYSQL_RES *result = NULL;
MYSQL_FIELD *field = NULL;
mysql_init(&mysql);
mysql_real_connect(&mysql, "localhost", "root", "root", "test", 3306, NULL, 0);
string str = "select id,name from t1;";
mysql_query(&mysql, sql.c_str());
result = mysql_store_result(&mysql);
int rowcount = mysql_num_rows(result);
cout << rowcount << endl;
int fieldcount = mysql_num_fields(result);
cout << fieldcount << endl;
for(int i = 0; i < fieldcount; i++)
{
field = mysql_fetch_field_direct(result,i);
cout << field->name << "\t\t";
}
cout << endl;
mysql_close(&mysql);
}

g++ -o 6.out 6.cpp -lmysqlclient -I/usr/include/mysql/ -L/usr/lib/mysql
./6.out

显示表中所有数据：

vi 7.cpp
#include
#include
#include

using namespace std;

main()
{
MYSQL mysql;
MYSQL_RES *result = NULL;
MYSQL_FIELD *field = NULL;
mysql_init(&mysql);
mysql_real_connect(&mysql, "localhost", "root", "root", 3306, NULL, 0);
string str = "select id,name from t1;";
mysql_query(&mysql, sql.c_str());
result = mysql_store_result(&mysql);
int rowcount = mysql_num_rows(result);
cout << rowcount << endl;
int fieldcount = mysql_num_fields(result);
cout << fieldcount << endl;
for(int i = 0; i < fieldcount; i++)
{
field = mysql_fetch_field_direct(result,i);
cout << field->name << "\t\t";
}
cout << endl;
MYSQL_ROW row = NULL;
row = mysql_fetch_row(result);
while(NULL != row)
{
for(int i=1; i {
cout << row[i] << "\t\t";
}
cout << endl;
row = mysql_fetch_row(result);
}
mysql_close(&mysql);
}

g++ -o 7.out 7.cpp -lmysqlclient -I/usr/include/mysql/ -L/usr/lib/mysql

./out

1. mysql_store_result：一次提取所有数据，像dataset
2. mysql_use_result：逐行提取数据，像datareader