[0:01]Connection ki query kya cheez hai? Iska purpose kya hai aur important kyun hai? PHP ke andar connection hum karte hain database ke saath. Database humara MySQL hai aur code humara jo PHP ka hota hai. Aur PHP jo hai na yeh server side language hai. Iska directly connection hi server ke saath hota hai. Front end pe yeh show nahi hoti hai. Matlab front end ka iska kaam nahi hai. Front end ke liye hum HTML, CSS aur Bootstrap ko use karte hain aur back end jo hai woh PHP ke saath humara hota hai. PHP ke andar hum queries likhte hain, commands dete hain. Aur jo humara jo data hota hai jo front end se hum data bhejte hain matlab save karte hain toh woh database mein jaa ke save hota hai. Database MySQL hai. SQL server ke about aap logo ne padha hoga CS 403 database management system ke andar. Toh iski total char commands hoti hain: insert, select, update aur delete. Inke bare mein aage padhenge ke insert ki command kis liye zaruri hai. Uske ilawa select ki kyun hai, kya hai? Update ki kya hai? Delete ki kya hai? Insert jaise naam se insert hai toh insert mean ke add karna. Aapne data add karna hai toh insert ki query lagayenge. SQL ki yeh commands kehlati hain. PHP ke andar hum inko query bolte hain. Insert ki query hai, data add karne ke liye use hoti hai. Select ki jo query hai woh data display karwane ke liye hoti hai. Aur delete ki jo update ki jo query hai, woh modify karne ke liye, edit karne ke liye, update karne ke liye use hoti hai. Aur jo delete ki query hai, yeh delete ke liye use hoti hai. Aur in sab se hat ke ek query hum use karte hain connection ki query, jiska kaam hota hai in sab queries ko aapas mein link karwana database ke saath. Agar aapka aapne koi program banaya hai toh us program mein zaruri hai ki aapka connection hona chahiye. Jab tak aapka database ke saath connection nahi hoga, tab tak jo hai woh aapka program run nahi hoga. Main aap logo ko bata raha tha ke jab bhi aap koi program karte ho, jab tak aapka aapke program ka database ke saath link nahi hoga, tab tak jo hai woh aapka program run nahi hoga. Toh PHP agar aap program kar rahe ho toh uske saath database ka connect karna zaruri hai. Simple yahi hai ki jab bhi hum agar aap general example lein connection ki, electricity ka ya koi bhi hai connection agar aapka woh theek nahi hoga toh tab tak aage aapka kaam nahi chal payega. Same agar programming mein aa jayein, koi bhi programming language hai uske andar ek base file hoti hai jisko connection, connectivity ki file bolte hain. Umm, waqai mein bhi yahi is tarah se poocha jata hai ke aapne connectivity kahan karwai hui hai. Toh woh maine bataya tha last time ke db.php file bhi ho sakti hai, database.php file bhi ho sakti hai, connection.php bhi ho sakti hai. Woh aapne koi bhi usko naam dena hota hai, woh uska rakh sakte hain naam. Toh uske liye kya karna hota hai? Sabse pehle yeh PHP ka opening syntax lagate hain aur yeh closing syntax lagate hain. Yahan pe aapne dollar sign hota hai. Dollar sign ka main bataya tha yeh common jo word hai yeh PHP ke andar use hota hai variable declare karne ke liye. Yahan pe jaise maine link yeh ek variable bana diya. CON CON use karte hain. DB variable connection ki query ko laga sakte hain. Koi bhi laga sakte hain toh variable ke liye zaruri nahi hai ki yahi ho. Aapki marzi hai but yeh wala jo hai na function yeh important hai. MySQLi underscore connect yeh important hai. Yeh aapka change nahi ho sakta, yeh fixed rahega. Aur iske andar baki phir aage char cheezein hoti hain connection ki query ke andar total char cheezein hum use karte hain connection karne ke liye. In char cheezo ke bagair humara jo hai na woh connection nahi ho payega. Aur jab tak end pe semicolon nahi lagayenge PHP ke program ke end pe, tab tak humara program nahi run ho payega. Toh kya kya hoga? Sabse pehle hum likhenge local host. Yahan pe root aayega. Yeh root humari directory kehlati hai jo ke hum jahan pe hum database banate hain.
[4:06]Yeh uski directory directory ko show karta hai. Aur aage humara jo tha database name humne banaya tha, woh humne students underscore 2026 ke naam se 2026 ke naam se banaya tha. Yeh humara db name kehlata hai. Dobaara bata doon, yeh PHP ka opening syntax hota hai. Yeh closing syntax hota hai. Aur yeh aapka variable kehlayega. Yeh next function hota hai jiske zariye aap database connect karte ho. Yeh aapka local host jo aapka server name hai jaise XAMP server hai ya WAMP server hai jo bhi server use karein. Yeh local host uske liye. Root yeh aapki PHP MyAdmin ki directory ke liye password local host pe blank hota hai password nahi rakhte. Aur yeh aapka DB name hota hai jo aap PHP MyAdmin mein jahan pe aap database bana rahe ho jo aapka database ka dashboard hai PHP MyAdmin jo kehlata hai wahan pe is naam se database banate hain. Toh uske liye database banane ke liye kya hai ki sabse pehle to aapke paas XAMP server start hona chahiye. XAMP server aapke paas hoga to tab hi yeh process ho payega. Uske liye aapne kya karna hai? Window ke start button pe click karna hota hai. Yahan pe XAMP likha, XAMP control panel pe click kiya. Aapke paas kuch is tarah se dashboard aa jata hai. Isme yeh jo is tarah se aayega. Toh aapne just do options ko start karna hai. Apache aur MySQL. Yeh bas do cheezein start karni hain, baki inko nahi chhedna hai. Jo teen hain neeche inko nahi. Jab yahan pe stop likha jayega in dono ke aage aur yeh numbering start ho jayegi, it's mean ki aapka XAMP server jo hai na yeh start ho chuka hai. Isko minimize kar dena hai. Idhar yahan pe aake aapne type karna hai local host. Yeh aapne khud type karna hai top URL bar ke andar slash phpMyAdmin. Aur end pe likh ke yeh likh ke enter kar dena hai. Yeh likh ke enter karenge, aapke paas yeh dashboard aa jayega, yeh wala. Ispe bhi aapke paas kuch is tarah se yeh aa raha hoga, yeh detail idhar agar aap log गौर करें, woh open karte ho to yahan pe bhi iski detail aa rahi hoti hai. Server, yeh IP kehlati hai, yeh local host isko IP bolte hain. Hum direct local host likh rahe hain lekin iski IP yeh kehlati hai. TCP IP. Server humara kaun sa hai? MySQL hai. Server ka version yeh bata raha hai. Aap logo ke paas jo bhi start hoga woh yeh aa raha. Aur protocol version 10, root user jo hai maine aapko bataya hai. Root@ the rate of local host, server aage uski characteristics bata rahe hain.
[6:30]Aur aage aapke paas jo web server kaun sa hai? Woh Apache web server hai. Yeh aapka database ka server hai MySQL aur jo web server aapka hai woh Apache hai. Yeh is cheez ko hi basically yeh jo XAMP ek application hai jo ke database ke liye hum use karte hain.
[6:48]Aur ab hum aate hain apne database ke upar. New database create karna ho to database pe jaate hain. Yahan pe aapne database ka naam likhna hota hai. Naam mein space nahi aani chahiye. Aur uske baad jo hai woh create ke button pe click kar dena hota hai. Yahan pe aake ab kya karna hai? Naam dena hai ke aapka database name kya hai? Toh students_2026 ke naam se humne data, database create ki thi. Toh iske baad aap check karna hota hai ki aapki yeh jo query hai, yeh wali, yeh theek chal rahi hai ki nahi chal rahi. Jab hum itna code kar lete hain isko aapne save karna hota hai. Save ke liye kya karenge? Ki file pe click kiya, save as pe click kiya. Uske baad yeh jo aapka folder hai iske andar koi bhi usko naam de diya. Jaise ab main isko naam de raha hoon connection.php ka. Last time database.php ka diya tha. Toh ab iske andar jo hai woh ab if-else condition lagani hai. If-else condition wohi jo C++, C++ mein CS 201 ke andar aap logo ne padha jisko C++ language bhi kehte hain. If mein value true hoti hai aur else mein value false hoti hai. Exception handling ke tor pe yeh use hoti hai PHP ke andar. Exception handling bolte hain error finding ko, matlab jiske zariye aap error find karein. Woh exception handling kehlata hai. Toh humne kya kiya hai ki yahan pe ab echo aur end pe semicolon yeh lazmi. Ab yahan pe connected ka likh dete hain. Bahut simple kar raha hoon. Yahan pe aapne bracket ke andar yeh dollar sign link lagana hota hai ke value jo aapki hai woh batani hoti hai ke yeh aapki value theek hai ya nahi. Uske baad else mein value false hoti hai. Aur isko bhi close kar diya. Aur yahan pe aake echo aur yahan pe main not likh diya. Isko bhi end pe semicolon laga diya. Abhi filhaal main just itna hi karta hoon. Last time aap logo ko maine Bootstrap karke dikhaya tha. Maybe usme aap log confused hue ho. Lekin iska jo method hai woh yeh hai. Iske baad aap file ko save karne ke liye control S karenge. File aapki save ho gayi. Ek just one time aapne save as karna hota hai aur uske baad phir control S karke file ko save karte jayenge. Ab hum kya karenge? Isko check karenge ke aaya ki humara program theek hai ya nahi. Browser mein aayenge Google Chrome pe yahan pe ab humne apne folder ka naam likhna hai jo humara HTdocs ke andar humne banaya tha. Folder kahan pe hoga jahan pe aapki XAMP ki installation hai. Jaise C drive hai C drive ke andar XAMP wala folder hai. XAMP wale folder ke andar HTdocs aur HTdocs ke andar aapka woh folder bana hoga. Toh yahan pe aapne kya likhna hai? Local host slash CS 619 project ke naam se maine folder banaya tha. Toh iske andar ab yeh meri file aa gayi connection.php ispe main click karunga toh woh dekhen woh keh raha hai ki connected hai. Ab isme main kuch mistakes karta hoon. Jaise maine yahan pe yeh six yeh hata diya. Toh yeh dekhen. Yeh error de dega, not ka yeh sign aa raha hai aur yeh isne kaha ki yeh unknown database hai. Database hai hi nahi is naam se. Yeh kar diya. Aur agar yeh semicolon nahi lagata tab kya aayega? Tab usne kaha ki syntax error hai. Syntax error ka matlab yeh hota hai ki aapne code aapka theek hai lekin PHP ke rule ke according aapne koi syntax miss kiya hai. Jispe yeh aa raha hai.
[10:15]Toh yahan tak tha database ki connectivity ke bare mein jo humne padha tha. Woh tha.
