databases your phone bill is a database …. m.cosgrave@ucc.ie @mikecosgrave

Databases

Your Phone Bill is a database…

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

Date Time Number Calling Duration

08-02-12 14:15 5556453 5551234 2:20

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

Flat File

Date Time Number Calling Duration20-10-11 16:39 5556453 5551234 2:20

20-10-11 17:10 5556453 5553456 1:23

20-10-11 17:12 4443456 4356324 2:14

20-10-11 17:12 2345873 0044202345 1:43:15

21-10-11 02:12 4567432 5679876 2:14

21_10_11 02:15 4567432 5679876 3:45

21-10-11 08:43 4536857 189056789 3:10

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

Date Time Number Calling Duration20-10-11 16:39 5556453 5551234 2:20

20-10-11 17:10 5556453 5553456 1:23

20-10-11 17:12 4443456 4356324 2:14

20-10-11 17:12 2345873 0044202345 1:43:15

21-10-11 02:12 4567432 5679876 2:14

21_10_11 02:15 4567432 5679876 3:45

21-10-11 08:43 5556453 189056789 3:10

Name House Street Town County Number5556453

CALLS

CUSTOMERS

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

• Entities• Relationships• One to many• Records• Tables

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

Date Time Number Calling Duration20-10-11 16:39 5556453 5551234 2:20

20-10-11 17:10 5556453 5553456 1:23

20-10-11 17:12 4443456 4356324 2:14

20-10-11 17:12 2345873 0044202345 1:43:15

21-10-11 02:12 4567432 5679876 2:14

21_10_11 02:15 4567432 5679876 3:45

21-10-11 08:43 5556453 189056789 3:10

Name House Street Town County Number5556453

CALLS

CUSTOMERS

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

Date Time Number Calling Duration20-10-11 16:39 5556453 5551234 http://

www.census.nationalarchives.ie/reels/nai000888383/

20-10-11 17:10 5556453 5553456 1:23

20-10-11 17:12 4443456 4356324 2:14

20-10-11 17:12 2345873 0044202345 1:43:15

21-10-11 02:12 4567432 5679876 2:14

21_10_11 02:15 4567432 5679876 3:45

21-10-11 08:43 5556453 189056789 3:10

Name House Street Town County Number5556453

CALLS

CUSTOMERS

SELECT ALL from CUSTOMERS, CALLS where Customers.number = calls.number and call.number=5556453

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

Finding Entities and Relationships

1946 Foreign Office List – service historiesPeople, postings, etcWhat are the Entities? The relationships?Draw an ER Diagram

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• Sample solutions to ER Diag exercise

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1901 Census of Ireland

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1901 Census Forms

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

1901 Census Forms

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Here’s one I prepared earlier..1901 Census in LibreOffice BaseParts of Database• Tables• Queries• Forms• Reports

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

Query By Example

• Show QBE

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Structured Query Language

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Interrogating data• Individuals• Families• Buildings

– Landholder– Class of Building– List of specific out buildings

• So how would you dig out– Literacy by Age?– Literacy by occupation?– Literacy by homeownership?– Religion and home ownership?– Children not in school?– Live in servants?– Servants and class of house?

m.cosgrave@ucc.ie www.mikecosgrave.com @mikecosgrave

• SQL Exercise

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Hollerith, 1890 Census, Hollerith Cards

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Coding, Datatypes

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• Coding exercise