aboutsummaryrefslogtreecommitdiffstats
path: root/lib/mnesia/doc/src/company_o.erl
diff options
context:
space:
mode:
Diffstat (limited to 'lib/mnesia/doc/src/company_o.erl')
-rw-r--r--lib/mnesia/doc/src/company_o.erl144
1 files changed, 144 insertions, 0 deletions
diff --git a/lib/mnesia/doc/src/company_o.erl b/lib/mnesia/doc/src/company_o.erl
new file mode 100644
index 0000000000..3c7ad0d5e5
--- /dev/null
+++ b/lib/mnesia/doc/src/company_o.erl
@@ -0,0 +1,144 @@
+%% ``The contents of this file are subject to the Erlang Public License,
+%% Version 1.1, (the "License"); you may not use this file except in
+%% compliance with the License. You should have received a copy of the
+%% Erlang Public License along with this software. If not, it can be
+%% retrieved via the world wide web at http://www.erlang.org/.
+%%
+%% Software distributed under the License is distributed on an "AS IS"
+%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+%% the License for the specific language governing rights and limitations
+%% under the License.
+%%
+%% The Initial Developer of the Original Code is Ericsson Utvecklings AB.
+%% Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
+%% AB. All Rights Reserved.''
+%%
+%% $Id$
+%%
+-module(company_o).
+-compile(export_all).
+
+-import(mnesia, [transaction/1]).
+
+%0
+-include_lib("stdlib/include/qlc.hrl").
+-include("company_o.hrl").
+
+
+sinit() ->
+ mnesia:create_schema([node()]).
+
+init() ->
+ mnesia:create_table(employee,
+ [{attributes, record_info(fields, employee)}]),
+ mnesia:create_table(dept,
+ [{attributes, record_info(fields, dept)}]),
+ mnesia:create_table(project,
+ [{attributes, record_info(fields, project)}]).
+
+%0
+
+
+
+%1
+
+insert_emp(Emp, DeptId, ProjNames) ->
+ Fun = fun() ->
+ mnesia:write(Emp#employee{dept = DeptId,
+ projects = ProjNames})
+ end,
+ mnesia:transaction(Fun).
+
+
+%1
+
+%2
+females() ->
+ F = fun() ->
+ Q = qlc:q([E#employee.name || E <- mnesia:table(employee),
+ E#employee.sex == female]),
+ qlc:e(Q)
+ end,
+ mnesia:transaction(F).
+%2
+
+%3
+female_bosses() ->
+ F = fun() -> qlc:e(qlc:q(
+ [{E#employee.name, Boss#employee.name} ||
+ E <- mnesia:table(employee),
+ Boss <- mnesia:table(employee),
+ Boss#employee.emp_no == E#employee.manager,
+ E#employee.sex == female]
+ ))
+ end,
+ mnesia:transaction(F).
+
+
+%4
+raise_females(Amount) ->
+ F = fun() ->
+ Q = qlc:q([E || E <- mnesia:table(employee),
+ E#employee.sex == female]),
+ Fs = qlc:e(Q),
+ over_write(Fs, Amount)
+ end,
+ mnesia:transaction(F).
+
+over_write([E|Tail], Amount) ->
+ Salary = E#employee.salary + Amount,
+ New = E#employee{salary = Salary},
+ mnesia:write(New),
+ 1 + over_write(Tail, Amount);
+over_write([], _) ->
+ 0.
+%4
+
+%5
+raise(Eno, Raise) ->
+ F = fun() ->
+ [E] = mnesia:read({employee, Eno}),
+ Salary = E#employee.salary + Raise,
+ New = E#employee{salary = Salary},
+ mnesia:write(New)
+ end,
+ mnesia:transaction(F).
+%5
+
+
+%6
+bad_raise(Eno, Raise) ->
+ F = fun() ->
+ [E] = mnesia:read({employee, Eno}),
+ Salary = E#employee.salary + Raise,
+ New = E#employee{salary = Salary},
+ io:format("Trying to write ... ~n", []),
+ mnesia:write(New)
+ end,
+ mnesia:transaction(F).
+%6
+
+%9
+get_emps(Salary, Dep) ->
+ Q = qlc:q(
+ [E || E <- mnesia:table(employee),
+ E#employee.salary > Salary,
+ E#employee.dept == Dep]
+ ),
+ F = fun() -> qlc:e(Q) end,
+ transaction(F).
+%9
+
+%10
+get_emps2(Salary, Dep) ->
+ Epat0 = mnesia:table_info(employee, wild_pattern),
+ Epat = Epat0#employee{dept = Dep},
+ F = fun() ->
+ All = mnesia:match_object(Epat),
+ [E || E <-All, E#employee.salary > Salary ]
+ end,
+ mnesia:transaction(F).
+
+
+%10
+