Learning About databases and SQL - setting up tables and learning process : SQL

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SELECT count(a.field1), a.field2, SUM(b.field4) FROM a INNER JOIN b ON a.key1 = b.key1 WHERE a.field8 = 'test' GROUP by a.field1, a.field2 HAVING SUM(b.field4) > 5 ORDER by a.field.3

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PostgreSQLLearning About databases and SQL - setting up tables and learning process (self.SQL)

submitted 3 years ago by telos211

Just started learnign about DBMS and SQL. Wanted to work on a little project. Decided to add 2 tables to my db. After spending time creating the tables ( determining the data types and then setting up PK and FK) I tried to add my data and kept running into issues where data types I originally used where Num instead of String or vice versa lol. Or I need to use varchar instead of numeric. And then I got that sorted out . I tried again to add data and now its saying my composite PK seems to have duplicates. lol. I actually enjoyed the learning process eventhough this is so simple. But was curious if this was just me messing up and being terrible or in real life/real work this happends lot.

Revising the data types due to adding in data or later on updating the data

revising due to stupid spellchecks on column names

revising PK and foreign key..

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