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Code Issues 16 Releases Wiki Activity

Fixed Oracle backend not to use extra_select for limit/offset type queries, which fixes a majority of the currently failing tests. Thanks, Ramiro Morales. 

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8445 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This commit is contained in:
Matt Boersma 2008-08-19 23:04:34 +00:00
parent e7769c36e9
commit db76b1e89d
1 changed files with 33 additions and 49 deletions
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82
django/db/backends/oracle/query.py
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@ -92,61 +92,45 @@ def query_class(QueryClass, Database):
# the SQL needed to use limit/offset w/Oracle.
do_offset = with_limits and (self.high_mark is not None
or self.low_mark)
# If no offsets, just return the result of the base class
# `as_sql`.
if not do_offset:
return super(OracleQuery, self).as_sql(with_limits=False,
with_col_aliases=with_col_aliases)
# `get_columns` needs to be called before `get_ordering` to
# populate `_select_alias`.
self.pre_sql_setup()
out_cols = self.get_columns()
ordering = self.get_ordering()
# Getting the "ORDER BY" SQL for the ROW_NUMBER() result.
if ordering:
rn_orderby = ', '.join(ordering)
else:
# Oracle's ROW_NUMBER() function always requires an
# order-by clause. So we need to define a default
# order-by, since none was provided.
qn = self.quote_name_unless_alias
opts = self.model._meta
rn_orderby = '%s.%s' % (qn(opts.db_table), qn(opts.fields[0].db_column or opts.fields[0].column))
# Getting the selection SQL and the params, which has the `rn`
# extra selection SQL.
self.extra_select['rn'] = 'ROW_NUMBER() OVER (ORDER BY %s )' % rn_orderby
sql, params = super(OracleQuery, self).as_sql(with_limits=False,
with_col_aliases=True)
with_col_aliases=with_col_aliases or do_offset)
if do_offset:
# Get the "ORDER BY" SQL for the ROW_NUMBER() result.
ordering = self.get_ordering()
if ordering:
rn_orderby = ', '.join(ordering)
else:
# Oracle's ROW_NUMBER() function always requires an
# order-by clause. So we need to define a default
# order-by, since none was provided.
qn = self.quote_name_unless_alias
opts = self.model._meta
rn_orderby = '%s.%s' % (qn(opts.db_table),
qn(opts.fields[0].db_column or opts.fields[0].column))
# Constructing the result SQL, using the initial select SQL
# obtained above.
result = ['SELECT * FROM (%s)' % sql]
# Collect all the selected column names or aliases.
outer_cols = []
for col in self.get_columns(True):
if ' AS ' in col:
outer_cols.append(col.split(' AS ', 1)[1])
else:
outer_cols.append(col.rsplit('.', 1)[1])
# Place WHERE condition on `rn` for the desired range.
result.append('WHERE rn > %d' % self.low_mark)
if self.high_mark is not None:
result.append('AND rn <= %d' % self.high_mark)
# Rewrite the original SQL query to select ROW_NUMBER() and involve
# it in the WHERE clause, then wrap everything in an outer SELECT
# statement that omits the "rn" column. This is the canonical way
# to emulate LIMIT and OFFSET on Oracle.
sql = 'SELECT ROW_NUMBER() OVER (ORDER BY %s) rn, %s' % (rn_orderby, sql[7:])
result = ['SELECT %s FROM (%s)' % (', '.join(outer_cols), sql)]
# Returning the SQL w/params.
return ' '.join(result), params
# Place WHERE condition on `rn` for the desired range.
result.append('WHERE rn > %d' % self.low_mark)
if self.high_mark is not None:
result.append('AND rn <= %d' % self.high_mark)
def set_limits(self, low=None, high=None):
super(OracleQuery, self).set_limits(low, high)
sql = ' '.join(result)
# We need to select the row number for the LIMIT/OFFSET sql.
# A placeholder is added to extra_select now, because as_sql is
# too late to be modifying extra_select. However, the actual sql
# depends on the ordering, so that is generated in as_sql.
self.extra_select['rn'] = '1'
def clear_limits(self):
super(OracleQuery, self).clear_limits()
if 'rn' in self.extra_select:
del self.extra_select['rn']
return sql, params
_classes[QueryClass] = OracleQuery
return OracleQuery