WEBVTT 00:00.330 --> 00:06.190 All right so we've covered the C and the and crud create and read now we're moving onto the you. 00:06.240 --> 00:07.770 Which stands for update. 00:08.100 --> 00:12.120 So how do we update or alter existing data in our database. 00:12.120 --> 00:14.870 We've inserted something and maybe we made a mistake. 00:14.910 --> 00:18.870 We want to change it but it's not always a mistake in our application. 00:18.870 --> 00:25.500 Let's say we have users think about when you're updating your password you forgot to password as a user. 00:25.620 --> 00:29.130 So you click the forget password link and you reset your password. 00:29.160 --> 00:34.110 Well that needs to be changed to the database or you change your profile picture on Facebook or you 00:34.110 --> 00:37.740 change your ID on a relationship status or something. 00:37.740 --> 00:39.750 All of that requires updating. 00:39.750 --> 00:41.010 So how do we do it. 00:41.610 --> 00:47.070 And the answer is that we use probably the longest sequel command you've seen so far. 00:47.130 --> 00:54.720 There's multiple parts but the key words are update set and where. 00:55.120 --> 01:01.800 So we've already seen where this is where we tell my Eskew will which items in particular we want to 01:01.800 --> 01:03.170 select to update. 01:03.180 --> 01:10.920 So in this case this entire line here is going to find in the cafe table all the cast who have a breed 01:10.920 --> 01:16.440 of Tabby and we're going to change that breed to be short hair. 01:16.440 --> 01:20.380 So again we have update and a table name then set. 01:20.430 --> 01:23.340 And this is a list of the changes we want to make. 01:23.340 --> 01:30.060 So in this case I'm setting the breed to be short here and then who do we want to or who is wrong way 01:30.060 --> 01:33.870 of saying it but what do we want to perform it on. 01:33.960 --> 01:37.360 What does the actual data in this case breed equals tabby. 01:37.360 --> 01:44.640 So I will go ahead and just copy this line move over here and if I do a select star from cat you can 01:44.640 --> 01:50.520 see that we have two Tabby's right now Ringo and misty. 01:50.700 --> 02:00.300 I paste this line and update cat changed their breed to be short hair if their breed is Tabby and now 02:00.300 --> 02:01.880 we select star again. 02:04.170 --> 02:11.580 You can see that both Tabby's are previously Tabby's are now shorthairs Misty and or excuse me Ringo 02:11.580 --> 02:14.930 and Misty. 02:15.000 --> 02:16.240 So here's another example. 02:16.680 --> 02:25.470 Let's say I wanted to change Misty's age to be 14 right now Misty is 13 and we realize I don't know 02:25.490 --> 02:28.460 we realize that her dental records are wrong. 02:28.470 --> 02:31.560 Apparently you can tell how well the cat is from their dental or from their teeth. 02:31.710 --> 02:38.910 So we misjudged how old she was and we want to make her 14 now so to do that looks like this. 02:38.910 --> 02:43.220 Update The cat's table set age to be 14. 02:43.230 --> 02:47.790 We don't need quotes this time because we're working with a number and integer and we only want to do 02:47.790 --> 02:50.380 that if name is Mysti. 02:50.640 --> 02:51.330 So let's try it 02:54.910 --> 02:55.180 now. 02:55.180 --> 02:56.440 So let's start again. 02:57.280 --> 02:59.740 Or actually you want to be more specific. 02:59.800 --> 03:10.550 We could do select star from cat where name equals Misty. 03:10.750 --> 03:15.060 Let's try that again without that extra L at the end. 03:15.130 --> 03:19.410 You can see Misty is now 14 rather than 13. 03:19.420 --> 03:23.560 The last thing that I'll mention about updating is that there is a good rule of thumb that you should 03:23.560 --> 03:29.050 follow when you're updating something you should make sure that you're targeting the right data before 03:29.050 --> 03:31.100 you actually do the update. 03:31.150 --> 03:38.200 So basically run the Select the equivalent select using your where query and once you make sure that 03:38.200 --> 03:43.810 returns the data you expect then update it just so that you avoid accidentally updating the wrong data. 03:43.900 --> 03:47.860 And the same holds true when we're talking about deleting which will do in just a moment but the core 03:47.860 --> 03:53.350 idea is that there is no undo button so you could update something back manually if you messed it up 03:53.590 --> 03:57.610 but you always want to just make sure you're targeting what you mean to target before you hit enter 03:57.610 --> 03:58.120 on your update.