Films · Computer science · SQL
Prof. Dr. Dirk Schieborn
AM3 Data Analysis and Machine Learning · Reutlingen University
Lecture film · AM3
Hamburg Customers, Flat Keys, Dead Links: Subqueries and Keys in SQL
Lecture film · AM3
Hamburg Customers, Flat Keys, Dead Links: Subqueries and Keys in SQL
Prof. Dr. Dirk Schieborn
AM3 Data Analysis and Machine Learning · Reutlingen University
A subquery is read from the inside out, and its result is a table. A foreign key turns a reference into a rule that the database watches over.
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More films: Signature · Prof. Dr. Dirk Schieborn
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Hamburg Customers, Flat Keys, Dead Links: Subqueries and Keys in SQL
Prof. Dr. Dirk SchiebornAM3 Data Analysis and Machine Learning · Reutlingen UniversityAn explainer film in six chapters, made from a real lecture: what NULL means and why it distorts the average, how short names for tables shorten a query and what the same statement looks like with join and on, why the database starts at from, how union throws two results into one pot, how to read a subquery from the inside out, and how primary and foreign keys prevent dead references. Pause anywhere and ask.
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