UPDATE Statement

Quick reference

• 00:04 In this video I wanna look at the update statement.
• 00:07 So we've learnt how to add data into our table with the insert statement.
• 00:12 Now, we need to learn how to update stuff, in case something changes over time.
• 00:17 Somebody's email address changes, so we need to update it.
• 00:20 Their home address changes, whatever.
• 00:22 We need a way to do that programmatically.
• 00:23 Of course, we can do that by hand by going, like we have in the past,
• 00:27 right clicking on here, typing in edit, highlighting the thing and
• 00:30 changing it by hand.
• 00:31 But most of the time, you're not gonna wanna do that.
• 00:33 You're gonna wanna do it programmatically.
• 00:34 So to do that, we use the update statement.
• 00:36 And it's pretty simple.
• 00:37 There's only one little thing you have to sort of pay attention to and
• 00:39 I'm gonna mention that in just a second.
• 00:42 So let's get rid of this and we can leave that as supposed.
• 00:47 So, this is our current table.
• 00:49 So, we've got Tracy Smitherton, maybe I misspelled Smitherton.
• 00:53 So, let's go ahead and update that.
• 00:54 So an update statement is pretty simple it's just Update.
• 00:58 That's one thing I like about SQL, everything is just simple.
• 01:01 You wanna update, you type update.
• 01:02 You wanna select, you type select.
• 01:04 You wanna insert, you type insert.
• 01:06 What could be simpler?
• 01:07 So the table name, so we dat and that.
• 01:11 And it's just dbo current customers.
• 01:15 And then, the next line is set and this is what you want to update.
• 01:19 We want to update last name and
• 01:22 we want to set it equal to lets say Smithertonly.
• 01:28 Okay, now here is the tricky part you have to type where, and
• 01:32 then give it a condition.
• 01:33 And if you don't do this, everything will get updated and you don't want that.
• 01:37 So you have to tell it exactly what to update.
• 01:39 We're saying update the last name column to Smithertonly.
• 01:43 If we don't tell it which specific record to update, it will update all of them, and
• 01:47 we don't want that.
• 01:48 So normally, when we design our database, we would give each of these like an ID
• 01:52 that was unique and we could use that in order to do this.
• 01:56 We did not do that so lets say where first name equals Tracy.
• 02:02 Change this to like, where the first name is like Tracy and
• 02:06 use the equal to with text, of course.
• 02:08 Okay so, now, we've executed it and it's Smithertonly and
• 02:13 none of the other records have changed.
• 02:16 So, pretty simple update, name your table,
• 02:20 set the thing equal to what you want to change.
• 02:23 Let's change this back to Smitherton.
• 02:26 We execute it again, boom Smitherton.
• 02:29 Don't forget your where statement right here.
• 02:33 Or else like I said, all of these columns will get changed.
• 02:36 And we don't want that.
• 02:37 So that's the update statement.
• 02:39 In the next video, we'll look at the delete statement.

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