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| author | Elizabeth Alexander Hunt <me@liz.coffee> | 2026-07-02 11:55:17 -0700 |
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| committer | Elizabeth Alexander Hunt <me@liz.coffee> | 2026-07-02 11:55:17 -0700 |
| commit | 6bf4b90c90f15f4ab60833bddf5b5756d1a6b1f6 (patch) | |
| tree | ed97e39ec77c5231ffd2c394493e68d00ddac5a4 /Homework/cs5800/Homeworks/hw-4.org | |
| download | misc-undergrad-6bf4b90c90f15f4ab60833bddf5b5756d1a6b1f6.tar.gz misc-undergrad-6bf4b90c90f15f4ab60833bddf5b5756d1a6b1f6.zip | |
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| -rw-r--r-- | Homework/cs5800/Homeworks/hw-4.org | 90 |
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diff --git a/Homework/cs5800/Homeworks/hw-4.org b/Homework/cs5800/Homeworks/hw-4.org new file mode 100644 index 0000000..3c6f8ba --- /dev/null +++ b/Homework/cs5800/Homeworks/hw-4.org @@ -0,0 +1,90 @@ +#+TITLE: Homework 4 +#+AUTHOR: Logan Hunt +#+DATE: October 8, 20222 + +* Question One +The number of super keys is the cardinality of the set of tuples of attributes that contain at least the clientId. In this case, that is: + +1. ~(clientId)~ +2. ~(clientId, name)~ +3. ~(clientId, phone)~ +4. ~(clientId, address)~ +5. ~(clientId, name, phone)~ +6. ~(clientId, name, address)~ +7. ~(clientId, phone, address)~ +8. ~(clientId, name, phone, address)~ + +Therefore there are eight super keys. + +* Question Two +There is only one primary key which is ~(clientId, empId, packageId)~. + +* Question Three +Salesman has two candidate keys empId and name, if we assume that each salesperson has a unique name. If not, then empId is the only candidate key (therefore, the primary key!). + +* Question Four +#+BEGIN_SRC sql +select clientId, name, phone, address from Client where name="Peter Smith"; +#+END_SRC + +* Question Five +#+BEGIN_SRC sql +select videoCode from Video where videoLength < 2; +#+END_SRC + +* Question Six +Making the assumption that all addresses are formatted as "<street no> <street address>". For example "12345 John Blvd": + +#+BEGIN_SRC sql +select siteCode, type, address, phone from Site + where right(address, locate(' ', address)-1) = "University Dr"; +#+END_SRC + +* Question Seven +#+BEGIN_SRC sql +select administrator.empId, administrator.name, administrator.gender from administers + join administrator on administrator.empId=administers.empId + where siteCode=111; +#+END_SRC + +* Question Eight +#+BEGIN_SRC sql +select salesman.empId, client.clientId, client.name, client.phone from client + join purchases on purchases.clientId = client.clientId + join salesman on salesman.empId = purchases.empId + where salesman.name="John"; +#+END_SRC + +* Question Nine +#+BEGIN_SRC sql +select digital_display.serialNo from digital_display + join locates on locates.serialNo=digital_display.serialNo + join site on site.siteCode=locates.siteCode + where site.siteCode = 112; +#+END_SRC + +* Question Ten +#+BEGIN_SRC sql +select distinct(digital_display.schedulerSystem) from digital_display + join locates on locates.serialNo=digital_display.serialNo + join site on site.siteCode=locates.siteCode + where site.siteCode = 112; +#+END_SRC + +* Question Eleven +#+BEGIN_SRC sql +select * from model where screenSize > 10 and weight < 3 +#+END_SRC + +* Question Twelve +#+BEGIN_SRC sql +select digital_display.serialNo, digitial_display.modelNo, digitial_display.schedulerSystem from digitial_display + join locates on locates.serialNo=digital_display.serialNo + join site on site.siteCode=locates.siteCode + where site.type="bar"; +#+END_SRC + +* Question Thirteen +#+BEGIN_SRC sql +select empId, day from adm_work_hours where hours > 8; +#+END_SRC sql |
