Database Design 35 - Introduction to Database Normalization — Transcript

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1. 0:00hey what's up everybody welcome back and
2. 0:02yes I know it is way past the deadline
3. 0:04for me to get my luscious Mane trimmed I
4. 0:08know you guys all love it but I'm just
5. 0:10going to keep it for a while so I know
6. 0:13it doesn't look too bad but I mean it it
7. 0:14really is bad I mean if I can pull my
8. 0:16hair past my lips that's it's kind of
9. 0:18bad but anyways this video is going to
10. 0:21be pretty simple I just want to
11. 0:24introduce a topic so in the next three
12. 0:26or so videos when we go over it it's
13. 0:29going to be like kind of not all new to
14. 0:32you you'll kind of have an idea of
15. 0:33what's going on so we're going over
16. 0:35what's known as
17. 0:36normalization so normalization is a
18. 0:39process where we go through our our
19. 0:43database plan that we have and we start
20. 0:46correcting things that may cause data
21. 0:48Integrity problems or just repeating
22. 0:51data etc etc whatever you want to
23. 0:55say the normal forms are basically like
24. 0:58a checklist that you're going to follow
25. 1:00and when you get to the end you'll have
26. 1:02a pretty good designed database so yeah
27. 1:06there's three main forms and these are
28. 1:09named very conveniently I have to admit
29. 1:13first normal
30. 1:15form second normal form and guess what
31. 1:18the third one is yeah you guessed it
32. 1:22third normal frame I'm kidding it's form
33. 1:25that'd be weird though all right so we
34. 1:27got first normal form second normal form
35. 1:29and third normal form
36. 1:30these are the three steps of
37. 1:32normalization for databases now if you
38. 1:34really really really want to get into
39. 1:36database design you're just like man I
40. 1:38love this stuff I got to get more well
41. 1:40there's tons and more steps you can add
42. 1:41and make things all complicated if you
43. 1:43really want but for our practical
44. 1:45purposes these are the only three that
45. 1:47you're going to really really need and I
46. 1:50know there's like a glare right here
47. 1:51because of these lights and I know I'm
48. 1:55just working on it so give me a couple
49. 1:56videos and I I'll try to work on my
50. 1:58lighting a bit but for now first normal
51. 2:01form second normal form third normal
52. 2:04form why do we have these well it's
53. 2:07because we want a systematic way to
54. 2:11follow to uh produce a normalized or a
55. 2:15good structure database all right
56. 2:18there's a couple things you should know
57. 2:19when it comes to normalization we still
58. 2:22have to talk about the idea of things
59. 2:24being Atomic we want everything to be
60. 2:26Atomic you also have to kind of think
61. 2:28about data dependent
62. 2:30on other data so if you think of like
63. 2:33let's say a primary key you got 608 just
64. 2:37a number that could refer to anything
65. 2:38that could be a person an order an event
66. 2:42whatever it is it's just a primary key
67. 2:44and that also is going to have different
68. 2:47columns in the table which have
69. 2:49different attributes about whatever this
70. 2:51thing is so let's say it's a person and
71. 2:54we have a column for the name and let's
72. 2:56say this dude's name is Caleb what a
73. 2:58dumb name right
74. 3:01uh this depends upon the primary
75. 3:05key so what I mean by that is if we
76. 3:07change the primary key we're going to
77. 3:09also change the person right so let's
78. 3:11say we have 609 well this is going to be
79. 3:15a completely different person right
80. 3:19because they're two separate entities
81. 3:21this one's referring to some guy over
82. 3:23here and this one is referring to some
83. 3:26guy over here two separate entities
84. 3:30you can also think oh by the way that
85. 3:31that process or that uh thing this is
86. 3:35called
87. 3:36dependency so the next three videos
88. 3:38we'll be going over the first normal
89. 3:39form second normal form and the third
90. 3:41normal form the other main thing is that
91. 3:45these are kind of comprehensive I guess
92. 3:46you could
93. 3:49say so what that means is once you have
94. 3:53first normal
95. 3:56form now you can go on to the second
96. 4:00normal form but you can't go jump in
97. 4:02right here you have to have it in first
98. 4:05normal form before you can get into
99. 4:07second normal form same thing for second
100. 4:09normal form into the third normal form
101. 4:13so that means if you have a database
102. 4:15that is in third normal form it is also
103. 4:18in second normal form and in first
104. 4:20normal form so I know I'm like getting
105. 4:23all this technical on terms and junk so
106. 4:25if it's freaking you out don't worry
107. 4:27it's really simple got to get my my hair
108. 4:29out out of my my face all right but
109. 4:33basically it's a it's um a list of steps
110. 4:37a list of things to do and basically you
111. 4:40can't do this step two until you do step
112. 4:43one so this here second normal form
113. 4:45that's step two can't do this until you
114. 4:48do that so you got to go through the
115. 4:50process and then once you're at third
116. 4:51normal form things are good to go so
117. 4:54yeah that's really all I have to say
118. 4:56peace