Working With Data Types

Quick reference

• 00:05 In this video, I wanna talk about Data Types.
• 00:07 So we've got our database, we've got our table, we've got our columns and rows.
• 00:10 Now, each column has to have a name, it also has to have a data type.
• 00:14 And a data type tells us what kind of data we have,
• 00:18 what is the type of data, data type.
• 00:20 For instance, we can add another column here, let's call it Age and 39.
• 00:24 So, 39 is a number and we have to, when we design our database,
• 00:28 when we set this up at the beginning we have to tell our database what kind of
• 00:33 data we expect in each field, right?
• 00:35 So in our Age field, we know this is gonna be a number, so
• 00:38 we're gonna tell it hey, it's gonna be a number.
• 00:41 Well, you have to know the types of data, it's just not a number,
• 00:44 in this case it would be an integer.
• 00:46 So, those different names and
• 00:47 those different types of data are what we're gonna talk about in this video.
• 00:51 So we have text in some of these, we have numbers in this one,
• 00:54 we have both numbers and text in this field right here, in this column.
• 00:59 So what's going on here?
• 00:59 So, in the world of database, there are many different types of data that we can
• 01:04 use and each type of database categorizes them slightly differently.
• 01:08 MySQL uses certain types of data or numbers.
• 01:12 SQL Server calls it something slightly different.
• 01:15 Every database handles data types differently.
• 01:17 So, my point is don't try and memorize this, because you can't.
• 01:21 If you switch from different servers, you're not gonna remember, SQL refers to
• 01:25 integers as integers, Postgres refers to them as floats, and on and on and on.
• 01:30 So, anytime you design a database, the first thing you wanna do is just look up
• 01:34 the different types of data for that specific server.
• 01:37 So we just go to Google, and in this course, we're gonna be using SQL Server,
• 01:41 Microsoft SQL Server.
• 01:42 So I would just type in something like, SQL Server database data types.
• 01:46 And you're gonna see all kinds of stuff.
• 01:49 There's the official one for Microsoft, that's a good one.
• 01:51 TutorialsPoint, they always have good ones.
• 01:53 So I'll just pull this one up and we'll look at this real quick.
• 01:56 There's not enough time for us to go into all of these in great detail but
• 01:59 you can see SQL Server offers six categories.
• 02:01 Actually they're seven, there's a miscellaneous one at the end.
• 02:04 But, they're broken into six main categories.
• 02:07 We have exact, number types, and in this one we're mainly gonna be using this int,
• 02:11 I-N-T which stands for integer.
• 02:13 Which is basically just a whole number without decimal point,
• 02:16 approximate number types, and I'll talk about these in just a second.
• 02:19 Date and Time, Character Strings, that's basically text.
• 02:23 And here are the main ones we're gonna be using are varchar and text.
• 02:26 Text, we'll use this,
• 02:28 it has a lot of limitations that we'll see as we go through the course.
• 02:31 Varchar stands for
• 02:32 Variable Characters and it's just strings of characters of different lengths.
• 02:37 And, you see there's max on here, you can designate exactly what length you want or
• 02:41 you just leave that off and it will just do the max.
• 02:44 A Unicode Character String, it's basically text but for Unicode.
• 02:48 And that deals a lot with different languages,
• 02:51 they might have slightly different alphabets.
• 02:54 Unicode deals with those types of things.
• 02:56 Binary Data Types, yes or no, true, false, that sort of thing.
• 03:00 And then we have Miscellaneous Data Types, timestamps, and XML,
• 03:03 and different things like that.
• 03:05 So you're not usually gonna use a lot of these miscellaneous.
• 03:09 You're not gonna use a lot of these, any of these.
• 03:11 The big ones you're gonna look at are character strings and numbers.
• 03:16 So if you know you're, back in the day, computer processing power was
• 03:20 not very big, and there was not a lot of storage on computers.
• 03:24 So every time you could keep your data as small as possible and
• 03:28 we could tell our database, only accept numbers with two digits.
• 03:33 Well, for that, we know the exact data type, it's a two digit number, right?
• 03:38 We can specify exactly how many bits and bytes and things.
• 03:41 These days it's not all that important, so personally I just use,
• 03:45 sort of approximate numbers and also approximate character strings.
• 03:49 I don't generally tell my databases to expect words of seven characters for
• 03:55 each column or whatever.
• 03:57 You'll learn more about this stuff as we go, but these are basic,
• 04:01 take a few minutes and look through these and Google a couple of different ones,
• 04:05 maybe read the Microsoft Docs.
• 04:07 And as we start to use SQL Server, you'll see these in action, and
• 04:10 then they'll make a lot of sense.
• 04:11 It's just a matter of saying, this is gonna be an integer,
• 04:14 this is gonna be text, this is gonna be a character, stuff like that.
• 04:17 So, that is data types, and
• 04:19 it's sort of the last important thing to understand about databases.
• 04:23 So databases have tables, columns, and rows.
• 04:25 In each of those columns, we have data of certain types, and
• 04:29 each column can only have a certain type of data.
• 04:32 So in the Age column, we would only put numbers, right?
• 04:35 We will not put John in an Age column because John is not a number.
• 04:39 So, just common sense, right?
• 04:41 So, that's Data Types.
• 04:43 In the next video, we'll start setting up Microsoft SQL Server 2016.
• 04:47 It's gonna be a lot of fun, and that's all for this video.

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