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+# syscat.py - parses some system catalogs
+# inspired from the PostgreSQL tutorial
+# adapted to Python 1995 by Pascal ANDRE
+
+print """
+__________________________________________________________________
+MODULE SYSCAT.PY : PARSES SOME POSTGRESQL SYSTEM CATALOGS
+
+This module is designed for being imported from python prompt
+
+In order to run the samples included here, first create a connection
+using : cnx = advanced.DB(...)
+
+The "..." should be replaced with whatever arguments you need to open an
+existing database. Usually all you need is the name of the database and,
+in fact, if it is the same as your login name, you can leave it empty.
+
+then start the demo with: syscat.demo(cnx)
+
+Some results may be empty, depending on your base status."
+
+__________________________________________________________________
+"""
+
+from pg import DB
+import sys
+
+# waits for a key
+def wait_key():
+ print "Press <enter>"
+ sys.stdin.read(1)
+
+# lists all simple indices
+def list_simple_ind(pgcnx):
+ result = pgcnx.query("""SELECT bc.relname AS class_name,
+ ic.relname AS index_name, a.attname
+ FROM pg_class bc, pg_class ic, pg_index i, pg_attribute a
+ WHERE i.indrelid = bc.oid AND i.indexrelid = bc.oid
+ AND i.indkey[0] = a.attnum AND a.attrelid = bc.oid
+ AND i.indproc = '0'::oid
+ ORDER BY class_name, index_name, attname""")
+ return result
+
+# list all user defined attributes and their type in user-defined classes
+def list_all_attr(pgcnx):
+ result = pgcnx.query("""SELECT c.relname, a.attname, t.typname
+ FROM pg_class c, pg_attribute a, pg_type t
+ WHERE c.relkind = 'r' and c.relname !~ '^pg_'
+ AND c.relname !~ '^Inv' and a.attnum > 0
+ AND a.attrelid = c.oid and a.atttypid = t.oid
+ ORDER BY relname, attname""")
+ return result
+
+# list all user defined base type
+def list_user_base_type(pgcnx):
+ result = pgcnx.query("""SELECT u.usename, t.typname
+ FROM pg_type t, pg_user u
+ WHERE u.usesysid = int2in(int4out(t.typowner))
+ AND t.typrelid = '0'::oid and t.typelem = '0'::oid
+ AND u.usename <> 'postgres' order by usename, typname""")
+ return result
+
+# list all right-unary operators
+def list_right_unary_operator(pgcnx):
+ result = pgcnx.query("""SELECT o.oprname AS right_unary,
+ lt.typname AS operand, result.typname AS return_type
+ FROM pg_operator o, pg_type lt, pg_type result
+ WHERE o.oprkind='r' and o.oprleft = lt.oid
+ AND o.oprresult = result.oid
+ ORDER BY operand""")
+ return result
+
+# list all left-unary operators
+def list_left_unary_operator(pgcnx):
+ result = pgcnx.query("""SELECT o.oprname AS left_unary,
+ rt.typname AS operand, result.typname AS return_type
+ FROM pg_operator o, pg_type rt, pg_type result
+ WHERE o.oprkind='l' AND o.oprright = rt.oid
+ AND o.oprresult = result.oid
+ ORDER BY operand""")
+ return result
+
+# list all binary operators
+def list_binary_operator(pgcnx):
+ result = pgcnx.query("""SELECT o.oprname AS binary_op,
+ rt.typname AS right_opr, lt.typname AS left_opr,
+ result.typname AS return_type
+ FROM pg_operator o, pg_type rt, pg_type lt, pg_type result
+ WHERE o.oprkind = 'b' AND o.oprright = rt.oid
+ AND o.oprleft = lt.oid AND o.oprresult = result.oid""")
+ return result
+
+# returns the name, args and return type from all function of lang l
+def list_lang_func(pgcnx, l):
+ result = pgcnx.query("""SELECT p.proname, p.pronargs, t.typname
+ FROM pg_proc p, pg_language l, pg_type t
+ WHERE p.prolang = l.oid AND p.prorettype = t.oid
+ AND l.lanname = '%s'
+ ORDER BY proname""" % l)
+ return result
+
+# lists all the aggregate functions and the type to which they can be applied
+def list_agg_func(pgcnx):
+ result = pgcnx.query("""SELECT a.aggname, t.typname
+ FROM pg_aggregate a, pg_type t
+ WHERE a.aggbasetype = t.oid
+ ORDER BY aggname, typname""")
+ return result
+
+# lists all the operator classes that can be used with each access method as
+# well as the operators that can be used with the respective operator classes
+def list_op_class(pgcnx):
+ result = pgcnx.query("""SELECT am.amname, opc.opcname, opr.oprname
+ FROM pg_am am, pg_amop amop, pg_opclass opc, pg_operator opr
+ WHERE amop.amopid = am.oid and amop.amopclaid = opc.oid
+ AND amop.amopopr = opr.oid order by amname, opcname, oprname""")
+ return result
+
+# demo function - runs all examples
+def demo(pgcnx):
+ import sys, os
+ save_stdout = sys.stdout
+ sys.stdout = os.popen("more", "w")
+ print "Listing simple indices ..."
+ print list_simple_ind(pgcnx)
+ print "Listing all attributes ..."
+ print list_all_attr(pgcnx)
+ print "Listing all user-defined base types ..."
+ print list_user_base_type(pgcnx)
+ print "Listing all left-unary operators defined ..."
+ print list_left_unary_operator(pgcnx)
+ print "Listing all right-unary operators defined ..."
+ print list_right_unary_operator(pgcnx)
+ print "Listing all binary operators ..."
+ print list_binary_operator(pgcnx)
+ print "Listing C external function linked ..."
+ print list_lang_func(pgcnx, 'C')
+ print "Listing C internal functions ..."
+ print list_lang_func(pgcnx, 'internal')
+ print "Listing SQL functions defined ..."
+ print list_lang_func(pgcnx, 'sql')
+ print "Listing 'aggregate functions' ..."
+ print list_agg_func(pgcnx)
+ print "Listing 'operator classes' ..."
+ print list_op_class(pgcnx)
+ del sys.stdout
+ sys.stdout = save_stdout