############################################### # # # Prepared Statements test on # # "nested sets" representing hierarchies # # # ############################################### # Source: http://kris.koehntopp.de/artikel/sql-self-references (dated 1999) # Source: http://dbmsmag.com/9603d06.html (dated 1996) --disable_warnings drop table if exists t1; --enable_warnings # "Nested Set": This table represents an employee list with a hierarchy tree. # The tree is not modeled by "parent" links but rather by showing the "left" # and "right" border of any person's "region". By convention, "l" < "r". # As it is a tree, these "regions" of two persons A and B are either disjoint, # or A's region is completely contained in B's (B.l < A.l < A.r < B.r: # B is A's boss), or vice versa. # Any other overlaps violate the model. See the references for more info. create table t1 ( id INTEGER AUTO_INCREMENT PRIMARY KEY, emp CHAR(10) NOT NULL, salary DECIMAL(6,2) NOT NULL, l INTEGER NOT NULL, r INTEGER NOT NULL); prepare st_ins from 'insert into t1 set emp = ?, salary = ?, l = ?, r = ?'; # Initial employee list: # Jerry ( Bert () Chuck ( Donna () Eddie () Fred () ) ) set @arg_nam= 'Jerry'; set @arg_sal= 1000; set @arg_l= 1; set @arg_r= 12; execute st_ins using @arg_nam, @arg_sal, @arg_l, @arg_r ; set @arg_nam= 'Bert'; set @arg_sal= 900; set @arg_l= 2; set @arg_r= 3; execute st_ins using @arg_nam, @arg_sal, @arg_l, @arg_r ; set @arg_nam= 'Chuck'; set @arg_sal= 900; set @arg_l= 4; set @arg_r= 11; execute st_ins using @arg_nam, @arg_sal, @arg_l, @arg_r ; set @arg_nam= 'Donna'; set @arg_sal= 800; set @arg_l= 5; set @arg_r= 6; execute st_ins using @arg_nam, @arg_sal, @arg_l, @arg_r ; set @arg_nam= 'Eddie'; set @arg_sal= 700; set @arg_l= 7; set @arg_r= 8; execute st_ins using @arg_nam, @arg_sal, @arg_l, @arg_r ; set @arg_nam= 'Fred'; set @arg_sal= 600; set @arg_l= 9; set @arg_r= 10; execute st_ins using @arg_nam, @arg_sal, @arg_l, @arg_r ; select * from t1; # Three successive raises, each one is 100 units for managers, 10 percent for others. prepare st_raise_base from 'update t1 set salary = salary * ( 1 + ? ) where r - l = 1'; prepare st_raise_mgr from 'update t1 set salary = salary + ? where r - l > 1'; let $1= 3; set @arg_percent= .10; set @arg_amount= 100; while ($1) { execute st_raise_base using @arg_percent; execute st_raise_mgr using @arg_amount; dec $1; } select * from t1; # Now, increase salary to a multiple of 50 (checks for bug#6138) prepare st_round from 'update t1 set salary = salary + ? - ( salary MOD ? )'; set @arg_round= 50; execute st_round using @arg_round, @arg_round; select * from t1; drop table t1; # End of 4.1 tests