okay, we have a. now what? suppose i need these two values every week on new data
TRANSCRIPT
Okay, we have a
Okay, we have a
Now what?
Suppose I need these two valuesEvery week
on new data
Don’t paste!
• Make repeatable
analyses (without
clicking)• Easily add data
Structured query language
Structured query language
• Developed at IBM
Structured query language
• Developed at IBM• Usually NOT considered
a programming language
Structured query language
• Developed at IBM• Usually NOT considered
a programming language
• But a “domain specific language”
Structured query language
• Developed at IBM• Usually NOT considered
a programming language
• But a “domain specific language”
• Aimed at analyzing and manipulating DATA
Suppose I need these two valuesEvery week
on new data
Where is
like ‘filter’
in Excel
But we need
temperature?
In Excel, we
did a lookup
Temperatur
e is here
To fix a bit (move
rows up)
This results in
Carthesian
product
This is called a ‘JOIN’
Very similar to
VLOOKUP
We have a
temperatur
e field now
We have the
filter
We still need to
show: Machine &
temperature
Benefit over Excel:
We can have
multiple such
queries
Benefit over Excel:
We can have
multiple such
queries
We have the
right data
We have the
right dataBut! We
need ‘pivot like’
summary on average
AVG of what?
Of everything?
Per machine?
AVG of what?
Of everything?
Per machine?
Almost there!
Almost there!
Suppose I need these two valuesEvery week
on new data
Remember lecture
1?
• Make repeatable
analyses (without
clicking)• Easily add data
Can’t pick
field names now
We made an easily
repeatable
analysis!