OS X - FileMerge 命令行交互技巧

2016-04-03 | Tools | Subversion

命令行调用

使用命令行指定两个文件，并用 FileMerge 去比较其差异。

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opendiff ${LEFT_FILE} ${RIGHT_FILE}
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MySQL 存储过程和函数区别

2016-04-01 | Database | MySQL

参考链接

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中篇小说五篇

2016-03-29 | Diary | Diary

迟到两周的读书笔记，仓促而惭愧的感想。

《化身博士》

半个小时后，当我再次、也是永远地变成我所深恶痛绝的那个人时，我知道我将坐在椅子上战栗着、哭泣着，或者就继续在房间里踱来踱去，聆听着每一声威胁，提心吊胆、失魂落魄。 —— 《化身博士》

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WebView 设置 UserAgent

2016-03-28 | iOS | iOSAndroidHTML

iOS

在 iOS 中的设置作用域为全局，一般在AppDelegate的初始化方法中设置即可。

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//  AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
    // ...
    
    NSDictionary *dictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"My Agent", @"UserAgent", nil];
    [[NSUserDefaults standardUserDefaults] registerDefaults:dictionary];
    
    return YES;
}
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MySQL 笔记 5

2016-03-24 | Database | NotesMySQL

视图

  • 视图是虚拟的表

视图的作用

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    MySQL 笔记 4

    2016-03-24 | Database | NotesMySQL

    插入数据

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    INSERT INTO customers VALUES(NULL, 'Fang');

    -- 推荐更安全、扩展性更好的方式
    INSERT INTO customers(cust_id, cust_name) VALUES(NULL, 'Fang');

    -- 进一步，无需插入 AUTO_INCREMENT 属性的列
    INSERT INTO customers(cust_name) VALUES('Fang');

    -- 插入多条数据，单条语句插入比多次语句性能更高
    INSERT INTO customers(cust_name) VALUES('Fang'), ('Quan');

    -- 插入检索出的数据
    INSERT INTO customers(cust_id, cust_name) SELECT cust_id, cust_name FROM custnew;
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    MySQL 笔记 3

    2016-03-23 | Database | NotesMySQL

    分组数据

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    SELECT vend_id COUNT(*) AS num_prods FROM products GROUP BY vend_id;

    SELECT cust_id, COUNT(*) AS orders FROM orders GROUP BY cust_id HAVING COUNT(*) >= 2;
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    MySQL 笔记 2

    2016-03-23 | Database | NotesMySQL

    创建计算字段

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    -- 拼接字段 Concat()
    SELECT Concat(vend_name, ' (', vend_country, ')') FROM vendors ORDER BY vend_name;

    -- Trim() 去除空格
    SELECT Concat(RTrim(vend_name), ' (', RTrim(vend_country), ')') FROM vendors ORDER BY vend_name;

    -- 使用别名 AS
    SELECT Concat(RTrim(vend_name), ' (', RTrim(vend_country), ')') AS vend_title FROM vendors ORDER BY vend_name;

    -- 执行算术计算
    SELECT prod_i， quantity, item_price, quantity*item_price AS expanded_price FROM orderitems WHERE order_num = 20005;
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    MySQL 笔记 1

    2016-03-23 | Database | NotesMySQL

    常用操作

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    -- 显示数据库
    SHOW DATABASES;

    -- 选择数据库
    USE some_db;

    -- 显示表
    SHOW TABLES;

    -- 显示表的列信息
    SHOW COLUMNS FROM some_table;
    DESCRIBE some_table;

    -- 显示数据库服务器状态信息
    SHOW STATUS;

    -- 显示授予用户的权限
    SHOW GRANTS;

    -- 显示服务器错误信息/警告信息
    SHOW ERRORS;
    SHOW WARNINGS;
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    Shell 结束某进程的子孙进程

    2016-03-17 | Tools | LinuxShell

    不知Linux原生是否有自带这类命令……

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    kill_pid_recursively()
    {
        local pid=$1
        local parent_pid=$2
        if [ ! -z ${pid} ]; then
            for child_pid in `pgrep -P ${pid}`; do
                kill_pid_recursively ${child_pid} ${pid}
            done
            echo "kill PID: ${pid}, its PPID is ${parent_pid}"
            kill -9 ${pid}
        fi
    }

    kill_pid_recursively ${SOME_PID} 'nothing'
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