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     SQL / PostgreSQL     How to Compare Arrays in PostgreSQL - PopSQL Basics:   Data types:                         - INT : whole number                         - VARCHAR(number_characters)                          - DATE : yyy-mm-dd                         - BLOB: binary large object to store large data                         - TIMESTAMP: yyyy-mm-dd hh:mm-ss Compare Arrays                1.  Equality operators (=, < >) do an exact element-by-element comparison                          select                           array[1, 2, 3] = array[1, 2, 4] as compare1,  -- array are equal                          array[1, 2, 3] < > = array[1, 2, 4] as compare2; --array are not equal                          - Compare1 is false.                          - Comapre2 is True.               2.  Ordering operators (>, <, >=, <=) also compare each element in an array in order. Result are                          based on the first different pair of element , not the s

  Solar Tracking System Dual Axis Solar Tracking System, Servo Motor for rotate system follow sun, LDR sensors to get signal from sun Professor: Dr. Kwanghoon Kim, Kanha UON Email: flyworld@gmail.com,   uonkanha99@gmail.com Department of Telecommunication and Electronic  Engineering Royal University of Phnom Penh, Cambodia   Abstract – The purpose of this studying is to build an algorithm to get high energy of solar                                        follow sun. Using algorithm, we can determine the value of each LDR sensor to control servos motor for moving system.     Keywords: Arduino Uno, LDR sensors, Servo Motor, Solar Panel, CN3791 MPPT Solar Charger.           I. Introduction      This report specified on solar follow sun of system provided from LDR sensors and translate the result into the motion of system to follow sun by using Servos Motor. The reason for learn this project is to get high energy by use dual-axis tracking system. Tracking mechanism ensur