CentOS C++数据库连接方法

在CentOS系统上使用C++连接数据库，通常需要使用相应的数据库客户端库。以下是一些常见数据库的C++连接方法：

1. MySQL

安装MySQL客户端库

sudo yum install mysql-devel 

示例代码

#include <mysql/mysql.h> #include <iostream> int main() { MYSQL *conn; MYSQL_RES *res; MYSQL_ROW row; conn = mysql_init(NULL); if (!mysql_real_connect(conn, "localhost", "user", "password", "database", 0, NULL, 0)) { fprintf(stderr, "%s\n", mysql_error(conn)); exit(1); } if (mysql_query(conn, "show tables")) { fprintf(stderr, "%s\n", mysql_error(conn)); exit(1); } res = mysql_use_result(conn); while ((row = mysql_fetch_row(res)) != NULL) { printf("%s \n", row[0]); } mysql_free_result(res); mysql_close(conn); return 0; } 

2. PostgreSQL

安装PostgreSQL客户端库

sudo yum install postgresql-devel 

示例代码

#include <libpq-fe.h> #include <iostream> int main() { PGconn *conn = PQconnectdb("host=localhost dbname=database user=user password=password"); if (PQstatus(conn) != CONNECTION_OK) { std::cerr << "Connection to database failed: " << PQerrorMessage(conn) << std::endl; PQfinish(conn); return 1; } PGresult *res = PQexec(conn, "SELECT * FROM table_name"); if (PQresultStatus(res) != PGRES_TUPLES_OK) { std::cerr << "SELECT failed: " << PQerrorMessage(conn) << std::endl; PQclear(res); PQfinish(conn); return 1; } int rows = PQntuples(res); for (int i = 0; i < rows; i++) { std::cout << PQgetvalue(res, i, 0) << std::endl; } PQclear(res); PQfinish(conn); return 0; } 

3. SQLite

安装SQLite

sudo yum install sqlite-devel 

示例代码

#include <sqlite3.h> #include <iostream> int main() { sqlite3 *db; char *err_msg = 0; int rc; rc = sqlite3_open("test.db", &db); if (rc != SQLITE_OK) { std::cerr << "Cannot open database: " << sqlite3_errmsg(db) << std::endl; sqlite3_close(db); return 1; } const char *sql = "CREATE TABLE IF NOT EXISTS COMPANY(" "ID INT PRIMARY KEY NOT NULL," "NAME TEXT NOT NULL," "AGE INT NOT NULL," "ADDRESS CHAR(50)," "SALARY REAL );"; rc = sqlite3_exec(db, sql, 0, 0, &err_msg); if (rc != SQLITE_OK) { std::cerr << "SQL error: " << err_msg << std::endl; sqlite3_free(err_msg); sqlite3_close(db); return 1; } sqlite3_close(db); return 0; } 

编译和运行

对于上述示例代码，你可以使用以下命令进行编译：

g++ -o myapp myapp.cpp -lmysqlclient # 对于MySQL g++ -o myapp myapp.cpp -lpq # 对于PostgreSQL g++ -o myapp myapp.cpp -lsqlite3 # 对于SQLite 

然后运行生成的可执行文件：

./myapp 

请根据你的实际需求和数据库类型选择合适的库和示例代码。