/* Define if you want each line saved to the history list in bashhist.c: bash_add_history() to be sent to syslog(). */ /* #define SYSLOG_HISTORY */ #if defined (SYSLOG_HISTORY) # define SYSLOG_FACILITY LOG_USER # defin
####### to ############# /* Define if you want each line saved to the history list in bashhist.c: bash_add_history() to be sent to syslog(). */ #define SYSLOG_HISTORY #if defined (SYSLOG_HISTORY) # define SYSLOG_FACILITY LOG_USER # defin
2 重新压缩成 tar 包
1 2 3
cd /home/rpmbuilder/rpmbuild/SOURCES rm -rf bash-4.3.30.tar.gz tar -zcvf bash-4.3.30.tar.gz bash-4.3.30
alter table tablename add row_name datatype constraint;
alter table users add tel int;
修改列
1 2 3
alter table tablename modify row_name datatype constraint;
alter table users modify tel varchar(50);
修改表明
1 2 3
alter table tablename change old_row new_row datatype constraint;
alter table users change tel telphone double;
删除列
1 2 3
alter table tablename drop row_name;
alter table users drop telphone;
修改表名
1 2 3
rename table old_table to new_table;
rename table users to user;
数据库表中添加数据
商品表：product
id (primary key,int)
name(varchar(100))
price(double)
1
笔记本
22
2
Google Pixel3
8800
3
RedMi 5A
400
1 2 3 4 5
> create table product( id int primary key auto_increment, name varchar(100) not null, price double );
1 2 3 4 5
insert into table_name(row_name1,row_name2...) values(value1,value2...);
insert into product(id,name,price) values(1,'笔记本','22'); insert into product(id,name,price) values(2,'Google Pixel3','8800'); insert into product(name,price) values('RedMi 5A','400');
数据库表中修改数据
1 2 3 4
update table_name set row1_name='value1',row2_name='value2' where condition
update product set price=30 where id=1; update product set price=2000 where id=2 or id=3;
数据库表中删除数据
1 2 3
delete from table_name where condiction;
delete from product where id=3;
SQL 查询语句
1 2 3 4 5
create table zhangwu( id int primary key auto_increment, names varchar(200), money double );
1
insert into zhangwu(names,money)values('服装支出',1000),('吃饭支出',325),('股票收入',8000),('打麻将支出',8000);
1
select id,names,money from zhangwu;//查询指定列的数据
条件查询
1 2 3
selete row_name from table_name where condition;
select id,names,money from zhangwu where money > 5000;
int main(){ int var = 20; int *ip; ip = &var; cout << "Value of var variable: " << var << endl; //输出在指针变量中存储的地址 cout << "Address stored in ip variable: " << ip << endl; //访问指针中地址的值 cout << "Value of *ip variable: " << *ip << endl; return 0; };
当上面的代码被编译和执行时，它会产生下列结果：
1 2 3
Value of var variable: 20 Address stored in ip variable: 0x7ffeefbff548 Value of *ip variable: 20
C++ 指针详解
在C++ 中，有很多指针相关的概念，这些概念都很简单，但是都很重要。下面列出了 C++ 程序员必须清楚的一些与指针相关的重要概念：
概念
描述
C++ Null 指针
C++ 支持空指针。NUll 指针时一个定义在标准库中的值为零的常量。
C++ 指针的算术运算
可以对指针进行四中算数运算 ++、–、+、-
C++ 指针 VS 数组
指针和数组之间有着密切的关系
C++ 指针数组
可以定义用来存储指针的数组
C++ 指向指针的指针
C++ 允许指向指针的指针
C++ 传递指针给函数
通过引用或地址传递参数，使传递的参数在调用函数中被改动
C++ 从函数返回指针
C++ 允许韩式返回指针到局部变量、静态变量和动态内存分配
]]>
<link rel="stylesheet" class="aplayer-secondary-style-marker" href="/assets/css/APlayer.min.css"><script src="/assets/js/APlayer.min.js" cla
Redmi 5A global 刷机https://dashage.github.io/2018/12/30/Redmi 5A global 刷机/2018-12-30T10:32:34.610Z2018-12-30T10:32:34.610Z
rule "fhq11" when contains(value: to_string($message.message), search: "<1>rule_id", ignore_case: false) then let f = key_value(to_string($message.message), ";" , ":"); set_fields(f); end
