Pg : add some SQL helpers

PgDB.py

@@ -1,8 +1,11 @@
 #!/usr/bin/python
+# -*- coding: utf-8 -*-
 
 import psycopg2
 import logging
 import sys
+import traceback
+import datetime
 
 class PgDB(object):
 
@@ -13,6 +16,9 @@ class PgDB(object):
 
 	con = 0
 
+	date_format = '%Y-%m-%d'
+	datetime_format = '%Y-%m-%d %H:%M:%S'
+
 	def __init__(self,host,user,pwd,db):
 		self.host = host
 		self.user = user
@@ -51,7 +57,7 @@ class PgDB(object):
 			self.con.commit()
 			return True
 		except Exception, e:
-			logging.error('Erreur durant la requete sql %s : %s' % (sql,e))
+			logging.error(u'Error during SQL request "%s" :\n\n%s' % (sql.decode('utf-8', 'ignore'), traceback.format_exc()))
 			self.con.rollback()
 			return False
 
@@ -62,5 +68,112 @@ class PgDB(object):
 			results = cursor.fetchall()
 			return results
 		except Exception, e:
-			logging.error('Erreur durant la requete sql %s : %s' % (sql,e))
+			logging.error(u'Error during SQL request "%s" :\n\n%s' % (sql.decode('utf-8', 'ignore'), traceback.format_exc()))
 			return False
+
+	#
+	# SQL helpers
+	#
+	def _quote_value(self, value):
+		if type(value) is int or type(value) is float:
+			return unicode(value)
+
+		if type(value) is str:
+			value = unicode(value)
+		elif type(value) is datetime.datetime:
+			value = unicode(self._format_datetime(value))
+		elif type(value) is datetime.date:
+			value = unicode(self._format_date(value))
+
+		return u"'%s'" % value.replace(u"'",u"''")
+
+	def _format_where_clauses(self, where_clauses, where_op=u'AND'):
+		if type(where_clauses) is str:
+			return where_clauses
+		elif type(where_clauses) is list:
+			return (u" %s " % where_op).join(where_clauses)
+		elif type(where_clauses) is dict:
+			return (u" %s " % where_op).join(map(lambda x: "%s=%s" % (x, _quote_value(where_clauses[x])), where_clauses))
+		logging.error('Unsupported where clauses type %s' % type(where_clauses))
+		return False
+
+	def _format_datetime(self, datetime):
+		return datetime.strftime(self.datetime_format)
+
+	def _format_date(self, date):
+		return date.strftime(self.date_format)
+
+	def time2datetime(self, time):
+		return self._format_datetime(datetime.fromtimestamp(int(time)))
+
+	def time2date(self, time):
+		return self._format_date(datetime.fromtimestamp(int(time)))
+
+	def insert(self, table, values, just_try=False):
+		sql=u"INSERT INTO %s (%s) VALUES (%s)" % (table, u', '.join(values.keys()), u", ".join(map(lambda x: self._quote_value(values[x]), values)))
+
+		if just_try:
+			logging.debug(u"Just-try mode : execute INSERT query : %s" % sql)
+			return True
+
+		logging.debug(sql)
+		if not self.doSQL(sql):
+			logging.error(u"Fail to execute INSERT query (SQL : %s)" % sql)
+			return False
+		return True
+
+	def update(self, table, values, where_clauses, where_op=u'AND', just_try=False):
+		where=self._format_where_clauses(where_clauses, where_op=where_op)
+		if not where:
+			return False
+
+		sql=u"UPDATE %s SET  %s WHERE %s" % (table, u", ".join(map(lambda x: "%s=%s" % (x, self._quote_value(values[x])), values)), where)
+
+		if just_try:
+			logging.debug(u"Just-try mode : execute UPDATE query : %s" % sql)
+			return True
+
+		logging.debug(sql)
+		if not self.doSQL(sql):
+			logging.error(u"Fail to execute UPDATE query (SQL : %s)" % sql)
+			return False
+		return True
+
+	def delete(self, table, where_clauses, where_op=u'AND', just_try=False):
+		where=self._format_where_clauses(where_clauses, where_op=where_op)
+		if not where:
+			return False
+
+		sql=u"DELETE FROM %s WHERE %s" % (table, where)
+
+		if just_try:
+			logging.debug(u"Just-try mode : execute DELETE query : %s" % sql)
+			return True
+
+		logging.debug(sql)
+		if not self.doSQL(sql):
+			logging.error(u"Fail to execute DELETE query (SQL : %s)" % sql)
+			return False
+		return True
+
+	def select(self, table, where_clauses=None, fields=None, where_op=u'AND', order_by=None, just_try=False):
+		sql = u"SELECT "
+		if fields is None:
+			sql += "*"
+		elif type(fields) in (str, unicode):
+			sql += fields
+		else:
+			sql += u", ".join(fields)
+
+		sql += u" FROM " + table
+		if where_clauses:
+			where=self._format_where_clauses(where_clauses, where_op=where_op)
+			if not where:
+				return False
+
+			sql += u" WHERE " + where
+
+		if order_by:
+			sql += u"ORDER %s" % order_by
+
+		return self.doSelect(sql)