PostgreSQL SELECT Operation: Practical Examples & Tips | #5

Hello, what's up, guys? Welcome, everyone, to Day 5 of Postgres SQL Today's video we'll be watching is about the Select Query Yes, guys, this is very important. You can see here, What all are we going to see today, Mene? Mine is basically like everyday There is a PPT file placed here with you all. And he isn't interested in theory either. And if you want to jump directly into practice, I've added the timeline. Please check in your timeline. The practical version of this is direct humming. You can check him out. But I'll suggest that you take a look at this once later. I am better than Taaki aapi. You can see it very clearly here. When we talk about the SELECT statement It means you have already inserted the data. We created tables, and we inserted the data into them. We saw different tariqas in yesterday's videos Now, if I need to read the data What should I do? Which query should I run for Tab? You can see it very clearly here. And that is simply using a SELECT statement What are you guys even talking about? Nothing at all. The database will ask a question. And whatever output is generated based on it I'll fetch it for you I will give it to you. Basically, when we don't talk Code operation What is this read here Toh usme aapka yeh select statement It's working, right? And you are writing a select statement Then you are in it You will mostly see You are beginners, aren't you? Starting me No one has an asterisk. This symbol that you are seeing They use it. What does this asterisk mean? However many columns there are Wherever you give me, you give me That's it. Give me Absolutely every column In this table So simple, is it? Don't worry, we will check the entire practical. Then we have something called alias What is an alias? If you sometimes Tables Basically the names of the columns Do you generate tables? They are not in such a readable format. You don't understand this at all. Right? What is that? Through his alias, we reach him I mean for a specific period of time As long as we are running the query I am one They give it a different name. You have a nickname, right? Isn't it very hot in your alias? They give him an alternate name. So that humans can read it easily Do you understand the column name? Just one What's up, bro? I don't like your name You gave him a different name. For Tohi As long as you are reading it So this is your alias. And you are useful, no doubt. Then we have this distinct If you don't need duplicate data Hey guys, in our case The table of users has roles in it. I just want to know this: Who are the roles in our table? There are only 3 or 4 such roles available. To show them 3 or 4 We will use this You will find out soon. And then, guys, at the end We have something called String concatenation You'll also enjoy this. And me, I give it to you Wow, I'm not that kind of person. In today's video, something like this What else have I learned today? Whatever you say Here you will learn something amazing. And there is one more thing It will come soon. When we talk about price At college Like, say Your tax has increased. Now about the tax that has just increased That new course's fee was charged to him. How much has it become? It's important, isn't it? You understand, right? It was 5000 before, wasn't it? He said that Fee increased by 10% How much has it become? You'll sit down after calculating a little bit How can we write this query? You'll enjoy it. So, without any delay, what? Let's start𫖳 But before that Today, our video's like target We keep it. Just 500 likes I didn't even get to see the views. How will likes come? But whatever you are seeing If you click the like button I will be very happy. Will get very motivated Guys, believe me With just one click of your like button One rupee will go to you I will get one rupee. But at least These videos until now You will definitely come to the meeting. In today's times With AI, guys You're the one who's crazy He is not learning anything. They will leave soon. But if you are learning Make sure that you Learn properly And from here to there If we share this We will do well. You understand karma, just get it I didn't subscribe to your channel Please do it then And the next target is 800,000 subscribers Alright Then, we proceed. Our The BS code editor was broken. Our Our PG admin 4 on So number one It's very simple indeed. Let's see All one hundred students Professors And admins We imported Basically If you remember Kalki We have completed the entire hundred Records are here He is going to do it. Now I want to see everything exactly. So very simple It's your choice. Asterisk We had just learned this Do you remember? Look at this asterisk Over here We just studied asterisk. A use case has come up from him Yeah, that's it Awesome So From which table From users table So run this simply here, and you'll see there's a segment. I'll show you what he said, he's right here, look, look, the whole thing Look ahead at the entire hundred records, hundred failures, buses were just there, weren't they? It keeps repeating over and over; I just need as many as there are—if there are three, then three. Just three are needed: admin, professor, and student — and they need to see us, okay? Alright, let me remove this. Okay, so check out how easy this is. Put an asterisk if you want to find everyone at once. If you need it, you keep it, okay? But it's our pin, you know. You didn't realize it either, but now you will know. Now we will tell you what If you're feeling down, what should I do? Or should I just send an email? I'll give them an alien, okay? As I have written to you But if we look closely Our name is a full flower name. Select Name You will have to write "S" Look, it must say the same thing here too Look, what's written here—this is it, this is yours, this is it, this is the keyword, it's here, so if you write it like this, you'll feel much better, but you can write it this way for anyone, but if your typing is good, then... As I wrote here, you write just what I wrote here. You'll feel it's good, brother, but after more dye, it'll look better. Then you write after this, but write correctly, properly. Here. You can see itdealer Full Name and then Contact You are seeing it in this way, it appears to you like this Yeah? Just a little bit I do it like that, man, it's fine So Full Name and then we have this Contact So it has become equal here; there is no problem at all. Everything is perfectly fine here. But let me tell you one thing As I have written Full Name here I'll give it a space from the letter. In place of Contact Just Contact? Contact Address Okay compatibly? Now I'm selecting it. I'm hitting it now. So, you see Something had to happen. Hey, look here — what do you see? Syntax Error At Our Near Name Select Name as Full Name Email As Whatever It May Be Syntax Error is showing So what's going on here? I will tell you. When you are using this kind of SELECT query When you are using alias When you wrote it in this way This name is a flower It has taken the flower, after all. Instead of a name, I'll show you flowers What is this name doing again? But we are talking about this one Alysis is the name I wanted to change it to instead. Because the flower name didn't feel good to me all at once I want this face in between them. It's simple, isn't it? What will you do? You will give it double quotes If there is this face in between them When you're giving the alien name And if this face is in between them Then you will have to use double quotes. And this is why it is appearing before you now. Because we were just running it But now let's run it back. And at this moment, it will become your turn. And you will get your data back. Look here, right here At this time, we have this flower name. And we have this contact address. So you've seen it How to select Even a base practice was seen in Elias. If you are using double words And if there is space between them Then you have to use double quotes Not even single quotes I will tell you. Not even single quotes Syntax error at or near fullness When you show me It will have to be paid When you give single quotes This data Your value is As students or computer science majors we are Put double quotes It has value I've seen a little value. I just wanted to give it a name, the value is a bit low, that's all. Nem is an alias name. Name column, so this will also be a column, double codes You need to keep in mind these small little things. Because mostly I have seen When we code, write double code, single code there It doesn't matter so much. Ante line unless both of you I mean, in one line, both double code and single code are coming for you. Then there's a little problem, otherwise it wouldn't happen. You need to provide the double code C here Do not provide a single code. Simple Alright, that's done. Let me just run it once. So that the error disappears from there Alright, that's fine, no problem. I mean, you said you're bulling, that your system is You run toward me. You will receive 100 out of 100 data today I don't even feel the need to speak to you. You will receive the complete 100 data of the roll today. Now what can be known? Exactly 90 days ago In 84, go to We had kept a separate role. More than one lux of data A lux from thick 200 before A private luxury car will arrive today. It is said somewhere that this is a matter of concern. Your one lux is excellent You'll go crazy. That address, that is This is it. Show it to me Write this down Just dodge it, it's fine here—just dodge it, and now hit it and see what comes out. So, three two one and boom, guys, look—this is exactly what I wanted. I'm done, I've figured it out. Good, it came out. I only have three rolls in me, that's all. Philal, now from this Fundart Record, the Hundred Court, I need to see you tomorrow in the case, if you have more data than my records, then there will be a clear indication of this there, so speak up and take it from those records, some of those roles were yours, now yours There are many things, but we haven't even seen them yet. That's in the select query, isn't it? We'll see it in the next video, but today If you need this individual column here, it's not important, and before stating the wow factor, you could have easily done it very easily, and it's not about whether you need it or not—I'm just saying. What should I do then? Look, you see from the cowshed Now, what's important for you here is this Yeah? Because I've written double codes here Because I had to treat him like a column. Now I'm saying here that I need all the records in the users table. But if this condition matches then Yeah? Now, where equals what? Where are you directly equal to? Yeah? Whether he's a professor or someone from the professor's side, let's just check it out. What is it? A certain professor, not a common one I run this one. Alright, Professor Is there a spelling mistake again? Where did the mistake happen, brother? Yeah, okay, see? Where am I? Look, I've explained this so clearly to all of you, and yet I'm the one who made the mistake. And that is the brother's value, isn't it? The column is short, professor, it's just a value, just data. Single quotes, well, it's for the best anyway Look here, the data has arrived, hasn't it? Look here, I've got the data now But only see their data, who are professors Just professors, I mean those whose role is now solely that of professors. I found their data here, Roll, just professors, look here, found it Otherwise, we have an admin, we also have students. But only professors, right? We've seen all this, haven't we? See how much Select can do. Now become a wow factor, just as I told you The college management has finally decided Whatever fees are applicable for your course now Basically, Tek's now want to add that ad. So you want to be in Thalst Databas, you're moving forward I mean, you now want him to be selective about how much you can afford. How much do you want this selection for? Okay? Well, now you tell us, isn't this Yusfoo? If you haven't liked the video yet, after seeing this,.gender, you must have felt it Yeah, bro, you're right. And by the way, there's one thing that comes to my mind Courses, which are Look here, I'll also file this thing for you. The courses, I've got them As I was using your user yesterday, the import Actually, I have imported it. Title, fee, and so we have this instructor ID Here you can see, okay I'll do one thing quickly for you guys, Select, Start, Form, Courses, OK I'm running it, look here, less jung, look here So the ID is, the title is, the fee is, the instructor ID is Advanced, Nejist, Architecture, Data Structure, Insi Plus Plus, Poscreas, Bootcam, Mansstek, Mastery, Machine Learning These are all our courses, and these are their fees. Instructor ID, all the IDs of those who are teaching them What exactly has happened here, that we've added a 13% tax? The government's new rule is that you will have to pay the fee, okay How will it be speaking, selecting, what will you feel here? Title, okay, so you'll get the fee, and I've given him a good alias Here I'm giving you the league fee, base fee, or, okay, what exactly does base fee mean? Then, regarding the new fees, the updated fees, what will they be for him, okay? So the title, which lets you know, Let's Foolspeak Class, or course, whatever the fee was, Let's 5000, now I'm going to do here, whatever the fee is, fee is fee, fee is fee, okay, fee, what happened, 13% increase Where from, courses, okay, in this way When I saw that the spelling we've done is correct, no problem, okay, so let's move on here, I've done the fees The price has increased; this was the fee, now it has become the fee itself. So understand this: I obtained Hari's data through a Y query, confirming that yes, the fee has increased, and the 13% tax has also increased. I've already displayed it here. Now it's become easy for me to know what belongs to whom and what doesn't. Now I... What's lying with me is your task for today, okay? This is your task. And when you run this query, you'll see what output you'll get, okay? I'll handle all of this myself, okay? And there's one more task for you. If I go ahead and do this here, we've already seen the Allite, so I've also kept the best practices here for you. Please go through them carefully. I've included both single and double ones here as well. Look here, when we had followed the math guy, what's written here—these are the follow-up board masses, or Pamdas, board mass—you must know what board mass is, right? So, keep this in mind: you need to do the plus first. Now you must first add it, whatever it is... What do you mean, even Bantari can't speak? When you say "expansion" or "expansion," we can say it. When you write it, if you put it inside double quotes, its priority increases, or this comes first... And there are many such things remaining. Just keep that in mind and apply. That's all I wanted to say, okay And here for you people I have also provided practice questions. So please go through this as well. the contact list Discover the departments, the welcome message what to retrieve name, email, and is active columns from the users table but alias them as this You understand, you need these three, but you You need to use the alias; this is what you're naming it. discover the department You need to discover the department. We have users assigned to the different departments. write the query to find clean list of all unique departments ID numbers currently in use inside the users table And you have to do the welcome message one. It's a joke, read it happily. I have kept this for you all, so that it may be for you all. And better practice, and for you all You can do this in a better way. It is this, that is it. You don't have the filth, and you were supposed to go to the park. When then went to it I'm talking about this damn fool Growing up with friends They are performing the copper ritual. You are pricking it. See you later, better than ever For this, I will do something for you. I will do it for you.