done for class today

11-26-18.sql

@@ -0,0 +1,49 @@
+UPDATE manager
+SET mresbuilding = 'B4'
+WHERE managerid = 'M34';
+
+-- dropping constraints is a good way to keep data but remove the foreign keys,
+-- typically constraints are done if the database is expected to be modified in the future.
+
+
+SELECT a.buildingid, a.aptno, c.ccname
+FROM apartment a
+LEFT OUTER JOIN corpclient c
+ON a.ccid = c.ccid;
+
+
+SELECT a.buildingid, a.aptno, c.ccname
+FROM apartment a
+RIGHT OUTER JOIN corpclient c
+ON a.ccid = c.ccid;
+
+-- a good diagram.
+-- https://i.stack.imgur.com/1UKp7.png
+-- BTW, FULL_OUTERMOST_JOIN is not in MySQL. Use a union of left and right outer joins.
+
+-- UNION eliminates duplicates
+
+-- JOIN doesn't actually require foreign keys. It just requires matched types
+-- FK's exist rather for you to keep your data organized and enforce integrity
+
+-- see q44 (we've modified it to have s.smembername, below)
+
+SELECT m.managerid, m.fname, m.mlname, s.smemberid, s.smembername
+FROM manager m, staffmember s
+WHERE m.mfname = s.smembername;
+
+-- q45. IS NULL
+
+SELECT *
+FROM manager
+WHERE mbonus IS NULL;
+
+-- Good for optional queries
+
+-- q46 EXISTS
+-- meh according to prof. Doesn't like it, always a better way
+
+-- IS NOT NULL (replaced q47)
+SELECT *
+FROM manager
+WHERE mbonus IS NOT NULL;