Linux下C++访问MySQL

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 <iostream>
#include <mysql/mysql.h>
#include <string>
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 <iostream>
#include <mysql/mysql.h>
#include <string>

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 <iostream>
#include <string>
#include <mysql/mysql.h>

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 <iostream>
#include <string>
#include <mysql/mysql.h>

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 <iostream>
#include <string>
#include <mysql/mysql.h>

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 <iostream>
#include <string>
#include <mysql/mysql.h>

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 <iostream>
#include <string>
#include <mysql/mysql.h>

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<fieldcount; 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