📙 FOR 310 - bconklin-champlain/Tech-Journal GitHub Wiki

SQL (Structure Query Language)

• SQL Lite
  • Most used database in the world
  • C Language

Refresher

SELECT * FROM table_name

Command	Explained
• SELECT	• column names here
• FROM	• table names here
• WHERE	• condition here
• GROUP BY	• column names here
• HAVING	• condition here
• ORDER BY	• column names here
• LIMIT	• number of desired items
• COUNT MIN MAX AVG SUM	• do some math on the table
• DISTINCT	• Show no duplicates
• BETWEEN	• Show something between a set of numbers

💡 BE CAREFUL OF NULL's!!!

SELECT *
FROM table_name AS (alias)
____ JOIN table_name
ON column = column
WHERE condition AND/OR condition
ORDER BY column_name ASC/DESC

SELECT * FROM table_name 
WHERE * is = x or is NULL

Command	Explained
• INNER JOIN	• only return connected matching rows
• LEFT JOIN	• returns all connected rows and unconnected from left table
• RIGHT JOIN	• returns all connected rows and unconnected from right table
• FULL JOIN	• returns connected rows and unconnected rows both left and right
• LIKE	• 'write anything your looking for'%

SELECT *
FROM Buildigs
LEFT JOIN Campus
ON Buildings.campus_id = Campus.id;

Extra Commands

Command	Explained
• DROP TABLE	• delete a table
• TRUNCATE TABLE	• delete the contents but keep the table

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Android Phones

Setting up Android Studio

• Anything with playstore is not rooted

Backing Up Android Device

1. Open adb (Android Debug Bridge)
2. Click directory and type 'cmd' this will open cmd from the current directory

Commands:

Command	Explained
• adb devices	• shows connected devices
• adb shell	• creates a shell in the device
• adb backup -f D:\adb-backup\backup1.adb -apk -obb -all -shared -system -keyvalue	• backup the device(these are all just options)
• java -jar abp.jar unpack X:\location X:\location	• changes the adb file into a tar file
• adb pull /data/data/app of app X:\destination_folder	• adb will pull and download folder
• adb root	• restarts a shell in root
• adb shell dumbsys -l	• creates a shell in the device then dumps the system files in a list
• adb shell dumpsys battery > dumpsys_info.txt	• creates a shell in the device then dumps the system files relating to the battery then creates a file with the output
• adb shell getprop	• creates a shell in the device and show more info on the device and services that are running
• adb shell pm list packages -f	• creates a shell in the device and list the packet manager and the packages on the system along with the file associated with them.
• adb shell pm list permission-groups	• creates a shell in the device and list permission groups
• adb shell pm list permissions	• creates a shell in the device and lists the permissions
• adb shell pm list feaures	• creates a shell in the device and lists the phones features
• adb shell pm list libraries	• creates a shell in the device and lists the libraries
• adb shell pm list users	• creates a shell in the device and lists users

CDR Retention from top three wireless networks in US

Company	CDR Retention Length
AT&T	7 Years
TMobile	3-5 years
Verizon	7-10 years
💡 TMobile canceled accounts are purged after account closes.

Sources:

AT&T Ref: 1 AT&T Ref: 2 All Ref: 1