[Reprint] The use of database foreign keysThe role of foreign keys:Maintain data consistency, integrity, the primary purpose is to control the data stored in the Foreign key table. Make two tables associative, and foreign keys can only refer to the values of columns in the outside!For example:A B two tablesAccount number in Table A, customer nameEach customer's order is stored in table BAfter having the foreign keyYou can only delete customer x in tab
[/*** adaptation Eclipse shortcut key * * the following man had this idea long ago * eclipseshortcutsforsublimetext2* http://icoloma.blogspot.com/2011/10/eclipse-shortcuts-for-sublime-text-2.html */{ "Keys": ["alt+/"], "command": "Auto_complete" },{ "Keys": ["ctrl+i"], "command ":" },// "Reindent" The current row and the following line interact in position { "Keys
MAC keyboard shortcutsYou can press the key combination to perform actions that typically require a mouse, trackpad, or other input device to complete.To use a keyboard shortcut, press and hold one or more modifier keys while pressing the last key of the shortcut key. For example, to use the shortcut key command-c (copy), hold down the Command key and press the C key, and then release both keys at the same
the role of foreign keys:
Maintain data consistency, integrity, the primary purpose is to control the data stored in the Foreign key table. Causes two tables to be associated, and the foreign key can only refer to the values of the columns in the outer table.
For example:
A B two tables
Account number in Table A, customer name
Each customer's order is stored in table B
After having the foreign key
You can only delete customer x in table A when you are
Common Windows Keys
Windows Key + Space keyFeatures: transparency of all windows, Quick view of the desktop. Use this shortcut to immediately make all of the currently open windows transparent so that you can view the desktop.
Windows key + Letter Key "D"function: minimize All windows and quickly view the desktop. This set of shortcuts helps the user immediately minimize all windows on the current desktop to view the desktop, and when the s
Original post address: http://ubuntuforums.org/showthread.php? T = 617349
Author: pmdematagda November 19th, 2007
Magicsysrq keys for maintenance ance with Ubuntu troubles
This guide consists of four parts :-
1) Introduction2) restarting Ubuntu safely when it is frozen.3) Shutting Down Ubuntu safely when it is frozen.4) brief descriptions about the keys you can use in magic sysrq sequences.5) controlli
//IP Scheduled Job Id/delete deletes a scheduled job on the remote computer
*at//IP all/delete Delete all scheduled jobs on the remote computer
Windows operating system shortcut keys
One, common usage:
F1 Displays the current program or Windows Help content.
F2 When you select a file, this means "rename"
F3 when you're on the desktop, open the Find: All Files dialog box
F10 or Alt activates the current program's menu bar
Windows key or Ctrl+es
Computer frequently used shortcut keys Daquan memorize the following shortcuts, you will be able to leave the mouse, light keyboard operation of the computer! Together to feel the pleasure of the computer master! A. Common usage: F1 Displays the current program or Windows Help content. F2 When you select a file, this means "rename" F3 When you are on the desktop, open the Find: All Files dialog box F10 or Alt activates the current program's men
Label:the role of foreign keys The main role of foreign keys is to maintain data consistency and integrity. About foreign keys, I have some of my own understanding, but I do not know whether it is correct, for example to express my view: If you need to build a table, what kind of table it? A student's personal information table for a class: So in the design, you
mention it in detail. In fact, in the "Preferences" this thing, there are many can be configuredThings, so that myeclipse optimization, specific to each person according to their own personal preferences to configure the
Eclipse Common shortcut keys
Eclipse's editing capabilities are powerful, and mastering the Eclipse shortcut key capabilities can greatly improve development efficiency. There are several shortcut
Eclipse's editing capabilities are powerful, and mastering the Eclipse shortcut key capabilities can greatly improve development efficiency. There are several shortcut keys related to editing in Eclipse.
1. "Alt+/"
This shortcut is a good helper for the user to edit, can provide users with the content of the auxiliary, do not worry about the method and the name of the property, when not the whole class, methods and attributes of the name, more exp
10 most useful shortcut key combinations in eclipse an eclipse-level developer summarizes the shortcut key combinations he thinks are the most useful but less known. These combinations make it easier to navigate through the source code, resulting in improved overall development efficiency and quality.1. Ctrl+shift+r: Open ResourceThis is probably the most time-saving combination of all shortcut keys. This set of shortcuts lets you open any file in you
Win10 shortcut key Daquan Everyone can come to know, today Small series brought win10 commonly used shortcut keys, many friends like to use shortcut keys to operate the computer, then WINDOWS10 system what new shortcut keys?• Snap window: Win + Left/right > win + up/down > window can be changed to 1/4 size placed in 4 corners of screen• Toggle window: Alt + Tab (
Common shortcut keysShortcut KeyCTRL + Shift + spacebarCTRL +-(character) create uninterrupted charactersCTRL + B to make the characters boldCTRL + I to make the characters ItalicCTRL + u add underline for charactersCTRL + Shift + zoom out font sizeCTRL + Shift +> increase the font sizeCTRL + q Delete paragraph formatCTRL + spacebar delete character formatCTRL + C copy the selected text or objectCTRL + x cut the selected text or objectCTRL + V paste text or objectCTRL + z undo the previous opera
Guidestoring SSH encryption keys and remembering passwords has always been a daunting problem. But unfortunately, in a world full of malicious hackers and attacks, basic security precautions are essential. For many ordinary users, most people can only remember the password, they may also find a good program to store the password, as we remind these users not to use the same password on each site. But for people in every IT field, we need to raise this
10 shortcut keys for MyEclipse:Ctrl + Shift + T: Open type: Displays the Open Type dialog box to open the type in the editor. The Open Type Selection dialog box shows all the types that exist in the workspace, such as classes, interfacessuch asCtrl + Shift + R: Open resource: Opens the Open Resource dialog box to open any resource in the workspace. Without having to browse files in the package Explorer, you can quickly open anyFile. Using this shortcu
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