C基本 mariadb處置的簡略實例。本站提示廣大學習愛好者：（C基本 mariadb處置的簡略實例）文章只能為提供參考，不一定能成為您想要的結果。以下是C基本 mariadb處置的簡略實例正文
引言
MariaDB 是一款灰常不錯開源數據庫. 這裡直接用它來處理營業成績.
營業需求：
如今數據庫中表現依照天禀表的. 忽然我們須要依照月來處置數據.
例如輸出一個玩家id, 查找這個玩家這個月內看了一件事幾回. 我們先搭建一個情況.
操作體系：
Linux version 4.4.0-22-generic (buildd@lgw01-41) (gcc version 5.3.1 20160413 (Ubuntu 5.3.1-14ubuntu2) ) #40-Ubuntu SMP Thu May 12 22:03:46 UTC 2016
起首裝置 MariaDB數據庫
sudo apt-get install mariadb-server sudo apt-get install mariadb-client sudo apt-get install libmariadb2 sudo apt-get install libmariadb-client-lgpl-dev sudo apt-get install libreoffice-mysql-connector
前面是C拜訪 MariaDB驅動. 這裡扯一點, 今朝關於MariaDB不懂成績, 搜不見直接當做mysql開端搜.
MariaDB裝置勝利後默許是開啟的, 看上面圖描寫
前面搭建測試情況 起首 看 oss_musicelves.sql
-- MySQL dump 10.10 -- -- Host: localhost Database: oss_log -- ------------------------------------------------------ -- Server version 5.5.24-tmysql-1.4 /*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */; /*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */; /*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */; /*!40101 SET NAMES utf8 */; /*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */; /*!40103 SET TIME_ZONE='+00:00' */; /*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */; /*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */; /*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */; /*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */; -- -- Table structure for table `oss_musicelves` -- DROP TABLE IF EXISTS `oss_musicelves`; CREATE TABLE `oss_musicelves` ( `record_id` bigint(20) NOT NULL AUTO_INCREMENT, `account_id` bigint(20) NOT NULL, `server_id` int(11) NOT NULL, `char_id` bigint(20) NOT NULL, `char_sex` int(11) NOT NULL, `type_id` int(11) NOT NULL, `timeStamp` datetime NOT NULL DEFAULT '0000-00-00 00:00:00', `ptype` int(11) NOT NULL, `specifytype` int(11) NOT NULL, `childtype` int(11) NOT NULL, PRIMARY KEY (`record_id`), KEY `idx_specifytype` (`specifytype`) ) ENGINE=InnoDB AUTO_INCREMENT=32 DEFAULT CHARSET=latin1; -- -- Dumping data for table `oss_musicelves` -- /*!40000 ALTER TABLE `oss_musicelves` DISABLE KEYS */; LOCK TABLES `oss_musicelves` WRITE; INSERT INTO `oss_musicelves` VALUES (1,411948833,84869352,27899597414400801,0,1812,'2016-05-31 14:27:41',0,1,1),(2,1344702709,90964200,30422720614402293,0,1812,'2016-05-31 14:58:26',0,1,1),(3,706409913,90964200,30422720614401465,1,1812,'2016-05-31 14:58:27',0,1,2),(4,706409913,392964857,30422720614401465,1,1812,'2016-05-31 14:58:59',0,2,4),(5,1344702709,392964857,30422720614402293,0,1812,'2016-05-31 14:58:59',0,2,4),(6,706409913,90964200,30422720614401465,1,1812,'2016-05-31 15:04:52',0,1,2),(7,706409913,392964857,30422720614401465,1,1812,'2016-05-31 15:05:54',0,2,4),(8,1344702709,392964857,30422720614402293,0,1812,'2016-05-31 15:05:54',0,2,4),(9,1344702709,90964200,30422720614402293,0,1812,'2016-05-31 15:10:29',0,1,1),(10,706409913,90964200,30422720614401465,1,1812,'2016-05-31 15:10:32',0,1,2),(11,1344702709,392964857,30422720614402293,0,1812,'2016-05-31 15:10:54',0,2,4),(12,3145910262,90964200,29520779366416374,1,1812,'2016-05-31 15:30:00',0,1,1),(13,1372825842,90964200,30173879500803314,1,1812,'2016-05-31 15:30:01',0,1,2),(14,3145910262,392964857,29520779366416374,1,1812,'2016-05-31 15:30:04',0,2,4),(15,1372825842,392964857,30173879500803314,1,1812,'2016-05-31 15:30:04',0,2,4),(16,3145910262,392964857,29520779366416374,1,1812,'2016-05-31 15:34:24',0,2,4),(17,1372825842,392964857,30173879500803314,1,1812,'2016-05-31 15:34:24',0,2,4),(18,706409913,90964200,30422720614401465,1,1812,'2016-05-31 15:40:14',0,1,1),(19,1344702709,90964200,30422720614402293,0,1812,'2016-05-31 15:40:16',0,1,2),(20,3145910262,392964857,29520779366416374,1,1812,'2016-05-31 15:42:19',0,2,4),(21,1372825842,392964857,30173879500803314,1,1812,'2016-05-31 15:42:19',0,2,4),(22,1027763684,90964200,30175730790400484,0,1812,'2016-05-31 16:56:33',1,1,1),(23,1372825842,90964200,30173879500803314,1,1812,'2016-05-31 16:56:50',0,1,2),(24,1372825842,392964857,30173879500803314,1,1812,'2016-05-31 16:57:37',0,2,3),(25,1027763684,392964857,30175730790400484,0,1812,'2016-05-31 16:57:37',1,2,3),(26,1372825842,392964857,30173879500803314,1,1812,'2016-05-31 17:04:33',0,2,3),(27,1027763684,392964857,30175730790400484,0,1812,'2016-05-31 17:04:33',1,2,3),(28,1027763684,90964200,30175730790400484,0,1812,'2016-05-31 17:14:15',1,1,2),(29,1372825842,392964857,30173879500803314,1,1812,'2016-05-31 17:14:50',0,2,3),(30,1027763684,392964857,30175730790400484,0,1812,'2016-05-31 17:14:50',1,2,3),(31,751699770,90964200,30175199027201850,1,1812,'2016-05-31 18:14:59',1,1,1); UNLOCK TABLES; /*!40000 ALTER TABLE `oss_musicelves` ENABLE KEYS */; /*!40103 SET TIME_ZONE=@OLD_TIME_ZONE */; /*!40101 SET SQL_MODE=@OLD_SQL_MODE */; /*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */; /*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */; /*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */; /*!40101 SET CHARACTER_SET_RESULTS=@OLD_CHARACTER_SET_RESULTS */; /*!40101 SET COLLATION_CONNECTION=@OLD_COLLATION_CONNECTION */; /*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;
這個 oss_musicelves.sql 文件重要功效是創立 oss_musicelves數據庫, 並填湊數據.
還有一個 搭建情況 的 劇本 mariadb_test.sql 和上一個sql文件放在統一個目次下
# 創立一個測試數據庫 create database oss_log; # 進入oss_log 數據庫 use oss_log; # 創立 oss_musicelves 數據庫, 並導入數據 source oss_musicelves.sql; # 批量創立表和數據 create table 2016_6_1_oss_musicelves select * from oss_musicelves; create table 2016_6_2_oss_musicelves select * from oss_musicelves; create table 2016_6_3_oss_musicelves select * from oss_musicelves; create table 2016_6_4_oss_musicelves select * from oss_musicelves; create table 2016_6_5_oss_musicelves select * from oss_musicelves; create table 2016_6_9_oss_musicelves select * from oss_musicelves; create table 2016_6_10_oss_musicelves select * from oss_musicelves; create table 2016_6_12_oss_musicelves select * from oss_musicelves; # 查詢表能否創立勝利 show tables; # 這裡處置 拿到的數據 select distinct table_name from information_schema.columns where table_name like '2016_6_%_oss_musicelves';
直接放在 MariaDB掌握台中直接刷出來. 搭建的詳細情況以下
到這裡情況根本搭建好了. MariaDB入門等等, 完整可以當作mysql 進修溫故一遍.
媒介
下面成績就是 本來 是 select * from oss_musicelves; 便可以處理的成績.
這裡 須要 輸出年和月 外加一些特別前提 . select * from %_%_%_oss_musicelves; 處理. 純真用sql劇本也能夠處理.異常龐雜.用的不熟.
這裡起首經由過程 shell 劇本處置
touch getmouths.sh chmod +x getmouths.sh vi getmouths.sh
詳細的劇本 內容 以下
#!/bin/sh
#獲得輸出的玩家ptid
if [ $# -lt 1 ]
then
echo "uage: $0 [ptid]"
exit -1
fi
ptid=$1
mouth=$(date +%m | sed s'/^0//')
#第一個參數是月份
if [ $# -ge 2 ]
then
mouth=$2
fi
#第二個參數是年
year=$(date +%Y)
if [ $# -ge 3 ]
then
year=$3
fi
#獲得查詢的隨機表名
tbname="\"${year}_${mouth}_%_oss_musicelves\""
#這裡獲得mysql 中一切正當表名
rm -rf __tmp
touch __tmp
#開端查詢數據庫了, 須要以root權限啟動這個劇本
mysql -e "select distinct table_name from information_schema.columns where table_name like $tbname" | awk 'NR>1' | while read name
do
mysql -e "select count(*) from oss_log.$name where specifytype = 1 and char_id = $ptid" | awk 'NR>1' | while read cut
do
echo "$name : $cut"
echo $cut >> __tmp
break
done
done
#統計內外面的數據
sum=$(cat __tmp | awk '{s+=$1} END {print s}')
rm -rf __tmp
# 最初輸入統計成果
echo "$year-$mouth sum: $sum"
應用劇本 截圖
經由過程shell可以完成 我們的需求. Linux上shell真好用. window的bat欠好用.
注釋
第一部門 : 讓C挪用MariaDB跑通
先看 測試Demo mariadb_demo.c
#include <stdio.h>
#include <stdlib.h>
#include <mysql.h>
/*
* 第一個 mariadb法式
*/
int main(int argc, char *argv[]) {
// 創立數據銜接對象
MYSQL *con = mysql_init(NULL);
if (con == NULL) {
fprintf(stderr, "%s\n", mysql_error(con));
exit(EXIT_FAILURE);
}
if (!mysql_real_connect(con, "localhost", "root", "", NULL, 0, NULL, 0)) {
fprintf(stderr, "%s\n", mysql_error(con));
mysql_close(con);
exit(EXIT_FAILURE);
}
if (mysql_query(con, "show databases;")) {
fprintf(stderr, "%s\n", mysql_error(con));
mysql_close(con);
exit(EXIT_FAILURE);
}
puts("mariadb is connect and run succesed!");
mysql_close(con);
return 0;
}
詳細的編譯 敕令
su root gcc -Wall -ggdb2 -I/usr/include/mariadb -o mariadb_demo.out mariadb_demo.c -lmysqlclient ./mariadb_demo.out
運轉成果 以下
到這裡根本C 挪用 MariaDB 根本流程跑通了. 然則很不爽. 只能經由過程root用戶應用.
那我們轉變這裡不爽. 進入第二部門. 擴大材料 c in mariadb http://stackoverflow.com/questions/17265471/using-mariadb-in-c
第二部門 : 經由過程通俗用戶完成營業需求.
先創立通俗用戶 csz, 暗碼是 1413222, 並而且給其 select 讀權限
su root mysql drop user csz; create user 'csz'@'%' identified by '13142222'; grant select on *.* to 'csz'@'%'; # 立刻刷新 flush privileges;
前面登錄嘗嘗
mysql -ucsz -p1314222 -h127.0.0.1
重要是mariadb默許封閉長途拜訪. 前面我們開啟平安拜訪形式嘗嘗
su root/etc/init.d/mysql stopmysqld_safe --skip-grant-tables
前面再開啟一個會話 . 從新輸出 mysql -ucsz -p1314222 -h127.0.0.1 , 處理可以了
#目的拼接 串內容 select sum(c) from ( select count(*) as c from 2016_6_1_oss_musicelves where specifytype=1 and char_id = 30422720614402293 union all select count(*) from 2016_6_2_oss_musicelves where specifytype=1 and char_id = 30422720614402293 union all select count(*) from 2016_6_3_oss_musicelves where specifytype=1 and char_id = 30422720614402293 union all select count(*) from 2016_6_4_oss_musicelves where specifytype=1 and char_id = 30422720614402293 union all select count(*) from 2016_6_5_oss_musicelves where specifytype=1 and char_id = 30422720614402293 union all select count(*) from 2016_6_9_oss_musicelves where specifytype=1 and char_id = 30422720614402293 union all select count(*) from 2016_6_10_oss_musicelves where specifytype=1 and char_id = 30422720614402293 union all select count(*) from 2016_6_12_oss_musicelves where specifytype=1 and char_id = 30422720614402293 ) as t;
詳細看 getmouths.c 文件 內容
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <mysql.h>
#define _INT_BUF (4098)
// 獲得查詢數據表內容
#define _STR_SQLTABLES \
"select distinct table_name from information_schema.columns where table_name like '%d_%d_%%_oss_musicelves'"
#define _STR_SQLSELECT \
"select count(*) as c from %s where specifytype=1 and char_id = %lld"
// 基本的mariadb 毛病封閉函數
static inline void _err_mariadb(MYSQL *con) {
fprintf(stderr, "_err_mariadb error: %s\n", mysql_error(con));
mysql_close(con);
exit(EXIT_FAILURE);
}
/*
* 處置 oss_musicelves 一個月的一切表.
*/
int main(int argc, char* argv[]) {
long long ptid;
time_t rt = time(NULL);
struct tm *pt = localtime(&rt);
int year = pt->tm_year + 1900;
int mouth = pt->tm_mon + 1;
// 先簡略檢測輸出
if(argc <= 1) {
fprintf(stderr, "%s [ptid] [mouth] [year]\n", argv[0]);
exit(EXIT_FAILURE);
}
// 先獲得 ptid 數據
ptid = atoll(argv[1]);
// 獲得以後月份
if(argc >= 3)
mouth = atoi(argv[2]);
// 獲得以後年份
if(argc >= 4)
year = atoi(argv[3]);
// 簡略檢測成果能否正當
if(ptid < 0 || mouth <=0 || mouth>12 || year<1900) {
fprintf(stderr, "%s %lld %d %d is error!\n", argv[0], ptid, mouth, year);
exit(EXIT_FAILURE);
}
// 輸入成果
printf("%s %lld %d %d start run!\n", argv[0], ptid, mouth, year);
// 開端用mysql 拜訪我們須要拜訪的數據成果了
MYSQL *con = mysql_init(NULL);
if(con == NULL) {
fprintf(stderr, "mysql_init error: %s\n", mysql_error(con));
exit(EXIT_FAILURE);
}
if(!mysql_real_connect(con, "127.0.0.1", "csz", "1314222", "oss_log", 0, NULL, 0))
_err_mariadb(con);
char sqls[_INT_BUF];
int sqlen = 0;
sprintf(sqls, _STR_SQLTABLES, year, mouth);
if(mysql_query(con, sqls))
_err_mariadb(con);
// 開端獲得成果
MYSQL_RES *ret = mysql_store_result(con);
if(NULL == ret)
_err_mariadb(con);
MYSQL_ROW row;
int i = 0, nr = 0;
while(!!(row = mysql_fetch_row(ret))) {
if(i == 0) {
sqlen = sprintf(sqls, "select sum(c) from (\n" _STR_SQLSELECT, row[0], ptid);
i = 1;
continue;
}
// 前面正常拼接
nr = sprintf(sqls + sqlen, "\nunion all\n" _STR_SQLSELECT, row[0], ptid);
if((sqlen += nr) >= _INT_BUF) {
fprintf(stderr, "sprintf while %d too length.\n", sqlen);
goto __return_free;
}
}
if(i == 0) {
printf("sum %lld %d/%d: 0\n", ptid, year, mouth);
goto __return_free;
}
// 這裡處置有的數據
nr = sprintf(sqls + sqlen, "\n) as t;");
if((sqlen += nr) >= _INT_BUF) {
fprintf(stderr, "sprintf end %d too length.\n", sqlen);
goto __return_free;
}
// 內存用完了就直接釋放
mysql_free_result(ret);
ret = NULL;
printf("sql : \n\t%s\n", sqls);
// 開端輸入統計成果
if(mysql_query(con, sqls))
_err_mariadb(con);
if((ret = mysql_store_result(con))==NULL)
_err_mariadb(con);
//獲得成果直接前往
if(!!(row=mysql_fetch_row(ret)))
printf("sum %lld %d/%d: %s\n", ptid, year, mouth, row[0]);
else
puts("select is empty!");
__return_free:
// 釋放用過的內存
mysql_free_result(ret);
// 封閉翻開的 數據庫拜訪對象
mysql_close(con);
return 0;
}
編譯敕令
gcc -Wall -ggdb2 -I/usr/include/mariadb -o getmouths.out getmouths.c -lmysqlclient
終究運轉成果是
假如想具體懂得關於mariadb c驅動的api應用, 可以參照老外寫的很好懂得.
mysqlc demo http://zetcode.com/db/mysqlc/
到這裡就停止了, 關於C 拜訪數據庫才能也根本買通了.
跋文
毛病是不免, 迎接進修提高~~~ 將來甚麼都不肯定, 可以肯定是沒有將來, 只要如今還在裝逼 .
以上這篇C基本 mariadb處置的簡略實例就是小編分享給年夜家的全體內容了，願望能給年夜家一個參考，也願望年夜家多多支撐。
