Written in C language database (a)

/***
connect.c
***/
#include<stdio.h>
#include<stdlib.h>
#include"mysql.h"

int main()
{
    MYSQL mysql;
    int t,r;
    mysql_init(&mysql);
    if(!mysql_real_connect(&mysql,"localhost","root","mysql123","csql",0,NULL,0))
    {
        printf("Error connecting to database:%s\n",mysql_error(&mysql));
    }
    else
    {
        printf("Connect MYSQL successfully!\n");
    }
    mysql_close(&mysql);
    return 0;
}

gcc编译：gcc connect.c -o connect -I /usr/include/mysql/ -L /usr/lib/mysql/ -lmysqlclient

/***
query
***/
#include<stdio.h>
#include<stdlib.h>
#include"mysql.h"

int main()
{
    MYSQL* conn_ptr;
    MYSQL_RES* res_ptr;
    MYSQL_ROW sqlrow;
    char taskID[256];
    char taskName[256];
    int res,i,j;
    
    conn_ptr = mysql_init(NULL);
    if(!conn_ptr)
    {
        return EXIT_FAILURE;
    }
    conn_ptr = mysql_real_connect(conn_ptr,"localhost","root","mysql123","csql",0,NULL,0);
    if(conn_ptr)
    {
        res = mysql_query(conn_ptr,"select * from task where taskState=4 order by taskLastEditTime desc");
        if(res)
        {
            printf("SELECT error:%s\n",mysql_error(conn_ptr));
        }
        else
        {
            res_ptr=mysql_store_result(conn_ptr);
            if(res_ptr)
            {
                printf("%lu Rows\n",(unsigned long)mysql_num_rows(res_ptr));
                j = mysql_num_fields(res_ptr);
                
                while((sqlrow = mysql_fetch_row(res_ptr)))
                {
                    for(i = 0 ; i  < j; i++)
                    {
                        printf("%s\t",sqlrow[i]);
                    }
                    printf("\n");
                    break;
                }
                if(mysql_errno(conn_ptr))
                {
                    fprintf(stderr,"Receive error:%s",mysql_error(conn_ptr));
                }
            }
            mysql_free_result(res_ptr);
        }
        if(res)
        {
            printf("mysql_insert error:%s\n",mysql_error(conn_ptr));
        }
    }
    else
    {
        printf("Connection failed\n");
    }
    mysql_close(conn_ptr);
    return EXIT_SUCCESS;
}

gcc编译：gcc query.c -o query -I /usr/include/mysql/ -L /usr/lib/mysql/ -lmysqlclient

/**
insert
***/
#include<stdio.h>
#include<stdlib.h>
#include"mysql.h"

int main(){
    MYSQL *conn_ptr;
    int res;
    
    conn_ptr = mysql_init(NULL);
    if(!conn_ptr){
        printf("mysql_init failed!\n");
        return EXIT_FAILURE;
    }
    conn_ptr = mysql_real_connect(conn_ptr,"localhost","root","shenhaoinfo","csql",0,NULL,0);
    if(conn_ptr){
        res = mysql_query(conn_ptr,"insert into children values(null,'jesffsui',5)");
        //
        if(!res){
            printf("Insert %lu rows\n",(unsigned long)mysql_affected_rows(conn_ptr));
        }else{
            fprintf(stderr,"insert error %d: %s\n",mysql_errno(conn_ptr),mysql_error(conn_ptr));
        }
    }else{
        printf("Connection failed\n");
    }
    mysql_close(conn_ptr);
    return EXIT_SUCCESS;
}

gcc编译：gcc insert.c -o insert -I /usr/include/mysql/ -L /usr/lib/mysql/ -lmysqlclient

/***
delete
***/
#include<stdio.h>
#include<stdlib.h>
#include"mysql.h"

int main(){
    MYSQL *conn_ptr;
    int res;
    
    conn_ptr = mysql_init(NULL);
    if(!conn_ptr){
        printf("mysql_init failed!\n");
        return EXIT_FAILURE;
    }
    conn_ptr = mysql_real_connect(conn_ptr,"localhost","root","shenhaoinfo","csql",0,NULL,0);
    if(conn_ptr){
        //res = mysql_query(conn_ptr,"insert into children values(null,'jesffsui',5)");
        res =mysql_query(conn_ptr,"delete from children where fname = 'jesffsui'");
        if(!res){
            printf("delete %lu rows\n",(unsigned long)mysql_affected_rows(conn_ptr));
        }else{
            fprintf(stderr,"delete error %d: %s\n",mysql_errno(conn_ptr),mysql_error(conn_ptr));
        }
    }else{
        printf("Connection failed\n");
    }
    mysql_close(conn_ptr);
    return EXIT_SUCCESS;
}

gcc编译：gcc delete.c -o delete -I /usr/include/mysql/ -L /usr/lib/mysql/ -lmysqlclient

Are uppercase i, represents INCLUDE, capital L, represents LINK, lowercase L, represents a link library

Whether the windows environment or linux environment, build links must bring libraries, header files and links to subsidiary mysql. How to configure the Internet written by other users are very detailed.