[c/c++] c 操作mysql数据库

输出mysql版本

#include <my_global.h>
#include <mysql.h>
#include <stdlib.h>
#include <stdio.h>

int main(int argc,char **argv) {
    printf("mysql client version:%s\n",mysql_get_client_info());
    return 0;
}

编译

gcc version.c -o version $(mysql_config --cflags --libs)

结果

$ ./version
mysql client version:5.1.63

创建DB

#include <my_global.h>
#include <mysql.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc,char **argv) {
    MYSQL *conn;

    conn = mysql_init(NULL);
    if(conn == NULL) {
        printf("Error %u:%s\n",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }

    // host user password 
    if(mysql_real_connect(conn,"localhost","root","admin",NULL,0,NULL,0) == NULL) {
        printf("Error %u:%s\n",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }

    char* sql = "CREATE DATABASE IF NOT EXISTS test_cdb";
    //char* sql = "CREATE database test_cdb";
    if(mysql_query(conn,sql)) {
        printf("Error %u:%s\n",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }

    mysql_close(conn);

    exit(EXIT_SUCCESS);
}

创建Table

#include <my_global.h>
#include <mysql.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc,char **argv) {
    MYSQL *conn;

    conn = mysql_init(NULL);
    // host user password dbname
    if(mysql_real_connect(conn,"localhost","root","admin","test_cdb",0,NULL,0) == NULL) {
        printf("Error %u:%s",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }

    char* sql = "CREATE TABLE IF NOT EXISTS test(name VARCHAR(25));";
    if(mysql_query(conn,sql)) {
        printf("Error %u:%s",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }
    sql = "INSERT INTO test VALUES('test1')";
    if(mysql_query(conn,sql)) {
        printf("Error %u:%s",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }

    mysql_close(conn);
    exit(EXIT_SUCCESS);
}

查询

#include <my_global.h>
#include <mysql.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc,char **argv) {
    MYSQL *conn;
    MYSQL_RES *result;
    MYSQL_ROW row;
    MYSQL_FIELD *field;

    int num_fields;
    int i;
    int j = 0;

    conn = mysql_init(NULL);
    if(mysql_real_connect(conn,"localhost","root","admin","test_cdb",0,NULL,0) == NULL) {
        printf("Error %u:%s",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }

    char* sql = "SELECT * FROM test";
    if(mysql_query(conn,sql)) {
        printf("Error %u:%s",mysql_errno(conn),mysql_error(conn));
        exit(EXIT_FAILURE);
    }
    result = mysql_store_result(conn);
    num_fields = mysql_num_fields(result); // 记录项数

    while((row = mysql_fetch_row(result))) {
        // for(int i = 0; i < num_fields;i++) { // allowed c99 mode
        for(i = 0; i < num_fields;i++) {
            if(j == 0) {
                // struct ?
                while(field = mysql_fetch_field(result)) {
                    printf("%s ",field->name);                    
                }
                printf("\n");
            }
            printf("%s ",row[i]? row[i] : "NULL");
        }
        printf("\n");
        j++;
    }
    mysql_free_result(result);

    mysql_close(conn);
    exit(EXIT_SUCCESS);
}