# +--------------------------------------------------------------------------+
# | Licensed Materials - Property of IBM |
# | |
# | (C) Copyright IBM Corporation 2009-2018. |
# +--------------------------------------------------------------------------+
# | This module complies with Django 1.0 and is |
# | Licensed under the Apache License, Version 2.0 (the "License"); |
# | you may not use this file except in compliance with the License. |
# | You may obtain a copy of the License at |
# | http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable |
# | law or agreed to in writing, software distributed under the License is |
# | distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
# | KIND, either express or implied. See the License for the specific |
# | language governing permissions and limitations under the License. |
# +--------------------------------------------------------------------------+
# | Authors: Ambrish Bhargava, Tarun Pasrija, Rahul Priyadarshi, |
# | Hemlata Bhatt, Vyshakh A |
# +--------------------------------------------------------------------------+
try:
from django.db.backends import BaseDatabaseOperations
except ImportError:
from django.db.backends.base.operations import BaseDatabaseOperations
from ibm_db_django import query
from django import VERSION as djangoVersion
import sys, datetime
try:
import pytz
except ImportError:
pytz = None
if ( djangoVersion[0:2] > ( 1, 1 ) ):
from django.db import utils
_IS_JYTHON = sys.platform.startswith( 'java' )
if( djangoVersion[0:2] >= ( 1, 4 ) ):
from django.utils.timezone import is_aware, is_naive, utc
from django.conf import settings
if _IS_JYTHON:
dbms_name = 'dbname'
else:
dbms_name = 'dbms_name'
class DatabaseOperations ( BaseDatabaseOperations ):
def __init__( self, connection ):
if( djangoVersion[0:2] >= ( 1, 4 ) ):
super( DatabaseOperations, self ).__init__(self)
else:
super( DatabaseOperations, self ).__init__()
self.connection = connection
if( djangoVersion[0:2] >= ( 1, 2 ) ):
compiler_module = "ibm_db_django.compiler"
def cache_key_culling_sql(self):
return '''SELECT cache_key
FROM (SELECT cache_key, ( ROW_NUMBER() OVER() ) AS ROWNUM FROM %s ORDER BY cache_key)
WHERE ROWNUM = %%s + 1
'''
def check_aggregate_support( self, aggregate ):
# In DB2 data type of the result is the same as the data type of the argument values for AVG aggregation
# But Django aspect in Float regardless of data types of argument value
# http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/index.jsp?topic=/com.ibm.db2.luw.apdv.cli.doc/doc/c0007645.html
if aggregate.sql_function == 'AVG':
aggregate.sql_template = '%(function)s(DOUBLE(%(field)s))'
#In DB2 equivalent sql function of STDDEV_POP is STDDEV
elif aggregate.sql_function == 'STDDEV_POP':
aggregate.sql_function = 'STDDEV'
#In DB2 equivalent sql function of VAR_SAMP is VARIENCE
elif aggregate.sql_function == 'VAR_POP':
aggregate.sql_function = 'VARIANCE'
#DB2 doesn't have sample standard deviation function
elif aggregate.sql_function == 'STDDEV_SAMP':
raise NotImplementedError("sample standard deviation function not supported")
#DB2 doesn't have sample variance function
elif aggregate.sql_function == 'VAR_SAMP':
raise NotImplementedError("sample variance function not supported")
def get_db_converters(self, expression):
converters =super(DatabaseOperations, self).get_db_converters(expression)
field_type = expression.output_field.get_internal_type()
if field_type in ( 'BinaryField', ):
converters.append(self.convert_binaryfield_value)
# else:
# converters.append(self.convert_empty_values)
"""Get a list of functions needed to convert field data.
Some field types on some backends do not provide data in the correct
format, this is the hook for coverter functions.
"""
return converters
def convert_empty_values(self, value, expression, context):
# Oracle stores empty strings as null. We need to undo this in
# order to adhere to the Django convention of using the empty
# string instead of null, but only if the field accepts the
# empty string.
field = expression.output_field
if value is None and field.empty_strings_allowed:
value = ''
if field.get_internal_type() == 'BinaryField':
value = b''
return value
def combine_expression( self, operator, sub_expressions ):
if operator == '%%':
return 'MOD(%s, %s)' % ( sub_expressions[0], sub_expressions[1] )
elif operator == '&':
return 'BITAND(%s, %s)' % ( sub_expressions[0], sub_expressions[1] )
elif operator == '|':
return 'BITOR(%s, %s)' % ( sub_expressions[0], sub_expressions[1] )
elif operator == '^':
return 'POWER(%s, %s)' % ( sub_expressions[0], sub_expressions[1] )
elif operator == '-':
if( djangoVersion[0:2] >= ( 2 , 0) ):
strr= str(sub_expressions[1])
sub_expressions[1] = strr.replace('+', '-')
else:
sub_expressions[1] = str.replace('+', '-')
return super( DatabaseOperations, self ).combine_expression( operator, sub_expressions )
else:
if( djangoVersion[0:2] >= (2 , 0)):
strr= str(sub_expressions[1])
sub_expressions[1]=strr.replace('+', '-')
else:
sub_expressions[1] = str.replace('+', '-')
return super( DatabaseOperations, self ).combine_expression( operator, sub_expressions )
if( djangoVersion[0:2] >= ( 1, 8 ) ):
def convert_binaryfield_value( self,value, expression,connections, context ):
return value
else:
def convert_binaryfield_value( self,value, expression, context ):
# field_type = field.get_internal_type()
# if field_type in ( 'BooleanField', 'NullBooleanField' ):
# if value in ( 0, 1 ):
# return bool( value )
#else:
return value
if( djangoVersion[0:2] >= ( 1, 8 ) ):
def format_for_duration_arithmetic(self, sql):
return ' %s MICROSECONDS' % sql
# Function to extract day, month or year from the date.
# Reference: http://publib.boulder.ibm.com/infocenter/db2luw/v9r5/topic/com.ibm.db2.luw.sql.ref.doc/doc/r0023457.html
def date_extract_sql( self, lookup_type, field_name ):
if lookup_type.upper() == 'WEEK_DAY':
return " DAYOFWEEK(%s) " % ( field_name )
else:
return " %s(%s) " % ( lookup_type.upper(), field_name )
def _get_utcoffset(self, tzname):
if pytz is None and tzname is not None:
NotSupportedError("Not supported without pytz")
else:
hr = 0
min = 0
tz = pytz.timezone(tzname)
td = tz.utcoffset(datetime.datetime(2012,1,1))
if td.days is -1:
min = (td.seconds % (60*60))/60 - 60
if min:
hr = td.seconds/(60*60) - 23
else:
hr = td.seconds/(60*60) - 24
else:
hr = td.seconds/(60*60)
min = (td.seconds % (60*60))/60
return hr, min
# Function to extract time zone-aware day, month or day of week from timestamps
def datetime_extract_sql(self, lookup_type, field_name, tzname):
if settings.USE_TZ:
hr, min = self._get_utcoffset(tzname)
if hr < 0:
field_name = "%s - %s HOURS - %s MINUTES" % (field_name, -hr, -min)
else:
field_name = "%s + %s HOURS + %s MINUTES" % (field_name, hr, min)
if lookup_type.upper() == 'WEEK_DAY':
return " DAYOFWEEK(%s) " % ( field_name ), []
else:
return " %s(%s) " % ( lookup_type.upper(), field_name ), []
# Truncating the date value on the basic of lookup type.
# e.g If input is 2008-12-04 and month then output will be 2008-12-01 00:00:00
# Reference: http://www.ibm.com/developerworks/data/library/samples/db2/0205udfs/index.html
def date_trunc_sql( self, lookup_type, field_name ):
sql = "TIMESTAMP(DATE(SUBSTR(CHAR(%s), 1, %d) || '%s'), TIME('00:00:00'))"
if lookup_type.upper() == 'DAY':
sql = sql % ( field_name, 10, '' )
elif lookup_type.upper() == 'MONTH':
sql = sql % ( field_name, 7, '-01' )
elif lookup_type.upper() == 'YEAR':
sql = sql % ( field_name, 4, '-01-01' )
if( djangoVersion[0:2] < ( 1, 6 ) ):
return sql
else:
return sql
# Truncating the time zone-aware timestamps value on the basic of lookup type
def datetime_trunc_sql( self, lookup_type, field_name, tzname ):
sql = "TIMESTAMP(SUBSTR(CHAR(%s), 1, %d) || '%s')"
if settings.USE_TZ:
hr, min = self._get_utcoffset(tzname)
if hr < 0:
field_name = "%s - %s HOURS - %s MINUTES" % (field_name, -hr, -min)
else:
field_name = "%s + %s HOURS + %s MINUTES" % (field_name, hr, min)
if lookup_type.upper() == 'SECOND':
sql = sql % ( field_name, 19, '.000000' )
if lookup_type.upper() == 'MINUTE':
sql = sql % ( field_name, 16, '.00.000000' )
elif lookup_type.upper() == 'HOUR':
sql = sql % ( field_name, 13, '.00.00.000000' )
elif lookup_type.upper() == 'DAY':
sql = sql % ( field_name, 10, '-00.00.00.000000' )
elif lookup_type.upper() == 'MONTH':
sql = sql % ( field_name, 7, '-01-00.00.00.000000' )
elif lookup_type.upper() == 'YEAR':
sql = sql % ( field_name, 4, '-01-01-00.00.00.000000' )
return sql, []
if( djangoVersion[0:2] >= ( 1, 8 ) ):
def date_interval_sql( self, timedelta ):
return " %d days + %d seconds + %d microseconds" % (
timedelta.days, timedelta.seconds, timedelta.microseconds), []
else:
def date_interval_sql( self, sql, connector, timedelta ):
date_interval_token = []
date_interval_token.append( sql )
date_interval_token.append( str( timedelta.days ) + " DAYS" )
if timedelta.seconds > 0:
date_interval_token.append( str( timedelta.seconds ) + " SECONDS" )
if timedelta.microseconds > 0:
date_interval_token.append( str( timedelta.microseconds ) + " MICROSECONDS" )
sql = "( %s )" % connector.join( date_interval_token )
return sql
#As casting is not required, so nothing is required to do in this function.
def datetime_cast_sql( self ):
return "%s"
def deferrable_sql( self ):
if getattr(self.connection.connection, dbms_name) == 'DB2':
return "ON DELETE NO ACTION NOT ENFORCED"
else:
return ""
# Function to return SQL from dropping foreign key.
def drop_foreignkey_sql( self ):
return "DROP FOREIGN KEY"
# Dropping auto generated property of the identity column.
def drop_sequence_sql( self, table ):
return "ALTER TABLE %s ALTER COLUMN ID DROP IDENTITY" % ( self.quote_name( table ) )
#This function casts the field and returns it for use in the where clause
def field_cast_sql( self, db_type, internal_type=None ):
if db_type == 'CLOB':
return "VARCHAR(%s, 4096)"
else:
return " %s"
def fulltext_search_sql( self, field_name ):
sql = "WHERE %s = ?" % field_name
return sql
# Function to return value of auto-generated field of last executed insert query.
def last_insert_id( self, cursor, table_name, pk_name ):
if not _IS_JYTHON:
return cursor.last_identity_val
else:
operation = 'SELECT IDENTITY_VAL_LOCAL() FROM SYSIBM.SYSDUMMY1'
cursor.execute( operation )
row = cursor.fetchone()
last_identity_val = None
if row is not None:
last_identity_val = int( row[0] )
return last_identity_val
# In case of WHERE clause, if the search is required to be case insensitive then converting
# left hand side field to upper.
def lookup_cast( self, lookup_type, internal_type=None ):
if lookup_type in ( 'iexact', 'icontains', 'istartswith', 'iendswith' ):
return "UPPER(%s)"
return "%s"
# As DB2 v91 specifications,
# Maximum length of a table name and Maximum length of a column name is 128
# http://publib.boulder.ibm.com/infocenter/db2e/v9r1/index.jsp?topic=/com.ibm.db2e.doc/db2elimits.html
def max_name_length( self ):
return 128
# As DB2 v97 specifications,
# Maximum length of a database name is 8
#http://publib.boulder.ibm.com/infocenter/db2luw/v9r7/topic/com.ibm.db2.luw.sql.ref.doc/doc/r0001029.html
def max_db_name_length( self ):
return 8
def no_limit_value( self ):
return None
# Method to point custom query class implementation.
def query_class( self, DefaultQueryClass ):
return query.query_class( DefaultQueryClass )
# Function to quote the name of schema, table and column.
def quote_name( self, name = None):
name = name.upper()
if( name.startswith( "\"" ) & name.endswith( "\"" ) ):
return name
if( name.startswith( "\"" ) ):
return "%s\"" % name
if( name.endswith( "\"" ) ):
return "\"%s" % name
return "\"%s\"" % name
# SQL to return RANDOM number.
# Reference: http://publib.boulder.ibm.com/infocenter/db2luw/v8/topic/com.ibm.db2.udb.doc/admin/r0000840.htm
def random_function_sql( self ):
return "SYSFUN.RAND()"
def regex_lookup(self, lookup_type):
if lookup_type == 'regex':
return '''xmlcast( xmlquery('fn:matches(xs:string($c), "%%s")' passing %s as "c") as varchar(5)) = 'true' db2regexExtraField(%s)'''
else:
return '''xmlcast( xmlquery('fn:matches(xs:string($c), "%%s", "i")' passing %s as "c") as varchar(5)) = 'true' db2regexExtraField(%s)'''
# As save-point is supported by DB2, following function will return SQL to create savepoint.
def savepoint_create_sql( self, sid ):
return "SAVEPOINT %s ON ROLLBACK RETAIN CURSORS" % sid
# Function to commit savepoint.
def savepoint_commit_sql( self, sid ):
return "RELEASE TO SAVEPOINT %s" % sid
# Function to rollback savepoint.
def savepoint_rollback_sql( self, sid ):
return "ROLLBACK TO SAVEPOINT %s" % sid
# Deleting all the rows from the list of tables provided and resetting all the
# sequences.
def sql_flush( self, style, tables, sequences, allow_cascade=False ):
curr_schema = self.connection.connection.get_current_schema().upper()
sqls = []
if tables:
#check for zOS DB2 server
if getattr(self.connection.connection, dbms_name) != 'DB2':
fk_tab = 'TABNAME'
fk_tabschema = 'TABSCHEMA'
fk_const = 'CONSTNAME'
fk_systab = 'SYSCAT.TABCONST'
type_check_string = "type = 'F' and"
sqls.append( '''CREATE PROCEDURE FKEY_ALT_CONST(django_tabname VARCHAR(128), curr_schema VARCHAR(128))
LANGUAGE SQL
P1: BEGIN
DECLARE fktable varchar(128);
DECLARE fkconst varchar(128);
DECLARE row_count integer;
DECLARE alter_fkey_sql varchar(350);
DECLARE cur1 CURSOR for SELECT %(fk_tab)s, %(fk_const)s FROM %(fk_systab)s WHERE %(type_check_string)s %(fk_tabschema)s = curr_schema and ENFORCED = 'N';
DECLARE cur2 CURSOR for SELECT %(fk_tab)s, %(fk_const)s FROM %(fk_systab)s WHERE %(type_check_string)s %(fk_tab)s = django_tabname and %(fk_tabschema)s = curr_schema and ENFORCED = 'Y';
IF ( django_tabname = '' ) THEN
SET row_count = 0;
SELECT count( * ) INTO row_count FROM %(fk_systab)s WHERE %(type_check_string)s %(fk_tabschema)s = curr_schema and ENFORCED = 'N';
IF ( row_count > 0 ) THEN
OPEN cur1;
WHILE( row_count > 0 ) DO
FETCH cur1 INTO fktable, fkconst;
IF ( LOCATE( ' ', fktable ) > 0 ) THEN
SET alter_fkey_sql = 'ALTER TABLE ' || '\"' || fktable || '\"' ||' ALTER FOREIGN KEY ';
ELSE
SET alter_fkey_sql = 'ALTER TABLE ' || fktable || ' ALTER FOREIGN KEY ';
END IF;
IF ( LOCATE( ' ', fkconst ) > 0) THEN
SET alter_fkey_sql = alter_fkey_sql || '\"' || fkconst || '\"' || ' ENFORCED';
ELSE
SET alter_fkey_sql = alter_fkey_sql || fkconst || ' ENFORCED';
END IF;
execute immediate alter_fkey_sql;
SET row_count = row_count - 1;
END WHILE;
CLOSE cur1;
END IF;
ELSE
SET row_count = 0;
SELECT count( * ) INTO row_count FROM %(fk_systab)s WHERE %(type_check_string)s %(fk_tab)s = django_tabname and %(fk_tabschema)s = curr_schema and ENFORCED = 'Y';
IF ( row_count > 0 ) THEN
OPEN cur2;
WHILE( row_count > 0 ) DO
FETCH cur2 INTO fktable, fkconst;
IF ( LOCATE( ' ', fktable ) > 0 ) THEN
SET alter_fkey_sql = 'ALTER TABLE ' || '\"' || fktable || '\"' ||' ALTER FOREIGN KEY ';
ELSE
SET alter_fkey_sql = 'ALTER TABLE ' || fktable || ' ALTER FOREIGN KEY ';
END IF;
IF ( LOCATE( ' ', fkconst ) > 0) THEN
SET alter_fkey_sql = alter_fkey_sql || '\"' || fkconst || '\"' || ' NOT ENFORCED';
ELSE
SET alter_fkey_sql = alter_fkey_sql || fkconst || ' NOT ENFORCED';
END IF;
execute immediate alter_fkey_sql;
SET row_count = row_count - 1;
END WHILE;
CLOSE cur2;
END IF;
END IF;
END P1''' % {'fk_tab':fk_tab, 'fk_tabschema':fk_tabschema, 'fk_const':fk_const, 'fk_systab':fk_systab, 'type_check_string':type_check_string} )
if getattr(self.connection.connection, dbms_name) != 'DB2':
for table in tables:
sqls.append( "CALL FKEY_ALT_CONST( '%s', '%s' );" % ( table.upper(), curr_schema ) )
else:
sqls = []
for table in tables:
sqls.append( style.SQL_KEYWORD( "DELETE" ) + " " +
style.SQL_KEYWORD( "FROM" ) + " " +
style.SQL_TABLE( "%s" % self.quote_name( table ) ) )
if getattr(self.connection.connection, dbms_name) != 'DB2':
sqls.append( "CALL FKEY_ALT_CONST( '' , '%s' );" % ( curr_schema, ) )
sqls.append( "DROP PROCEDURE FKEY_ALT_CONST;" )
for sequence in sequences:
if( sequence['column'] != None ):
sqls.append( style.SQL_KEYWORD( "ALTER TABLE" ) + " " +
style.SQL_TABLE( "%s" % self.quote_name( sequence['table'] ) ) +
" " + style.SQL_KEYWORD( "ALTER COLUMN" ) + " %s "
% self.quote_name( sequence['column'] ) +
style.SQL_KEYWORD( "RESTART WITH 1" ) )
return sqls
else:
return []
# Table many contains rows when this is get called, hence resetting sequence
# to a large value (10000).
def sequence_reset_sql( self, style, model_list ):
from django.db import models
cursor = self.connection.cursor()
sqls = []
for model in model_list:
table = model._meta.db_table
for field in model._meta.local_fields:
if isinstance( field, models.AutoField ):
max_sql = "SELECT MAX(%s) FROM %s" % ( self.quote_name( field.column ), self.quote_name( table ) )
cursor.execute( max_sql )
max_id = [row[0] for row in cursor.fetchall()]
if max_id[0] == None:
max_id[0] = 0
sqls.append( style.SQL_KEYWORD( "ALTER TABLE" ) + " " +
style.SQL_TABLE( "%s" % self.quote_name( table ) ) +
" " + style.SQL_KEYWORD( "ALTER COLUMN" ) + " %s "
% self.quote_name( field.column ) +
style.SQL_KEYWORD( "RESTART WITH %s" % ( max_id[0] + 1 ) ) )
break
for field in model._meta.many_to_many:
m2m_table = field.m2m_db_table()
if( djangoVersion[0:2] < ( 1, 9 ) ):
if field.rel is not None and hasattr(field.rel,'through'):
flag = field.rel.through
else:
flag = False
else:
if field.remote_field is not None and hasattr(field.remote_field,'through'):
flag= field.remote_field.through
else:
flag = False
if not flag:
max_sql = "SELECT MAX(%s) FROM %s" % ( self.quote_name( 'ID' ), self.quote_name( table ) )
cursor.execute( max_sql )
max_id = [row[0] for row in cursor.fetchall()]
if max_id[0] == None:
max_id[0] = 0
sqls.append( style.SQL_KEYWORD( "ALTER TABLE" ) + " " +
style.SQL_TABLE( "%s" % self.quote_name( m2m_table ) ) +
" " + style.SQL_KEYWORD( "ALTER COLUMN" ) + " %s "
% self.quote_name( 'ID' ) +
style.SQL_KEYWORD( "RESTART WITH %s" % ( max_id[0] + 1 ) ) )
if cursor:
cursor.close()
return sqls
# Returns sqls to reset the passed sequences
def sequence_reset_by_name_sql(self, style, sequences):
sqls = []
for seq in sequences:
sqls.append( style.SQL_KEYWORD( "ALTER TABLE" ) + " " +
style.SQL_TABLE( "%s" % self.quote_name( seq.get('table') ) ) +
" " + style.SQL_KEYWORD( "ALTER COLUMN" ) + " %s " % self.quote_name( seq.get('column') ) +
style.SQL_KEYWORD( "RESTART WITH %s" % ( 1 ) ))
return sqls
def tablespace_sql( self, tablespace, inline = False ):
# inline is used for column indexes defined in-line with column definition, like:
# CREATE TABLE "TABLE1" ("ID_OTHER" VARCHAR(20) NOT NULL UNIQUE) IN "TABLESPACE1";
# couldn't find support for this in create table
# (http://publib.boulder.ibm.com/infocenter/db2luw/v9/topic/com.ibm.db2.udb.admin.doc/doc/r0000927.htm)
if inline:
sql = ""
else:
sql = "IN %s" % self.quote_name( tablespace )
return sql
def value_to_db_datetime( self, value ):
if value is None:
return None
if( djangoVersion[0:2] <= ( 1, 3 ) ):
#DB2 doesn't support time zone aware datetime
if ( value.tzinfo is not None ):
raise ValueError( "Timezone aware datetime not supported" )
else:
return value
else:
if is_aware(value):
if settings.USE_TZ:
value = value.astimezone( utc ).replace( tzinfo=None )
else:
raise ValueError( "Timezone aware datetime not supported" )
return unicode( value )
def value_to_db_time( self, value ):
if value is None:
return None
if( djangoVersion[0:2] <= ( 1, 3 ) ):
#DB2 doesn't support time zone aware time
if ( value.tzinfo is not None ):
raise ValueError( "Timezone aware time not supported" )
else:
return value
else:
if is_aware(value):
raise ValueError( "Timezone aware time not supported" )
else:
return value
def year_lookup_bounds_for_date_field( self, value ):
if sys.version_info.major >= 3:
lower_bound = datetime.date(int(value), 1, 1)
upper_bound = datetime.date(int(value), 12, 31)
else:
lower_bound = datetime.date(long(value), 1, 1)
upper_bound = datetime.date(long(value), 12, 31)
return [lower_bound, upper_bound]
def bulk_insert_sql(self, fields, num_values):
if sys.version_info.major >= 3:
var_param=(int)
else:
var_param=(int,long)
values_sql = "( %s )" %(", ".join( ["%s"] * len(fields)))
if isinstance(num_values,var_param):
bulk_values_sql = "VALUES " + ", ".join([values_sql] * (num_values) )
else:
bulk_values_sql = "VALUES " + ", ".join([values_sql] * len(num_values) )
return bulk_values_sql
def for_update_sql(self, nowait=False):
#DB2 doesn't support nowait select for update
if nowait:
if ( djangoVersion[0:2] > ( 1, 1 ) ):
raise utils.DatabaseError( "Nowait Select for update not supported " )
else:
raise ValueError( "Nowait Select for update not supported " )
else:
return 'WITH RS USE AND KEEP UPDATE LOCKS'
def distinct_sql(self, fields):
if fields:
raise ValueError( "distinct_on_fields not supported" )
else:
return 'DISTINCT'
