def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
return Ref(name, self.annotation_select[name])
else:
return self.annotation_select[name]
else:
field_list = name.split(LOOKUP_SEP)
field, sources, opts, join_list, path = self.setup_joins(
field_list, self.get_meta(),
self.get_initial_alias(), reuse)
targets, _, join_list = self.trim_joins(sources, join_list, path)
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
if reuse is not None:
reuse.update(join_list)
col = targets[0].get_col(join_list[-1], sources[0])
return col
python类Ref()的实例源码
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
return Ref(name, self.annotation_select[name])
else:
return self.annotation_select[name]
else:
field_list = name.split(LOOKUP_SEP)
field, sources, opts, join_list, path = self.setup_joins(
field_list, self.get_meta(),
self.get_initial_alias(), reuse)
targets, _, join_list = self.trim_joins(sources, join_list, path)
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
if reuse is not None:
reuse.update(join_list)
col = targets[0].get_col(join_list[-1], sources[0])
return col
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
return Ref(name, self.annotation_select[name])
else:
return self.annotation_select[name]
else:
field_list = name.split(LOOKUP_SEP)
field, sources, opts, join_list, path = self.setup_joins(
field_list, self.get_meta(),
self.get_initial_alias(), reuse)
targets, _, join_list = self.trim_joins(sources, join_list, path)
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
if reuse is not None:
reuse.update(join_list)
col = targets[0].get_col(join_list[-1], sources[0])
return col
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
return Ref(name, self.annotation_select[name])
else:
return self.annotation_select[name]
else:
field_list = name.split(LOOKUP_SEP)
field, sources, opts, join_list, path = self.setup_joins(
field_list, self.get_meta(),
self.get_initial_alias(), reuse)
targets, _, join_list = self.trim_joins(sources, join_list, path)
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
if reuse is not None:
reuse.update(join_list)
col = targets[0].get_col(join_list[-1], sources[0])
return col
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
return Ref(name, self.annotation_select[name])
else:
return self.annotation_select[name]
else:
field_list = name.split(LOOKUP_SEP)
field, sources, opts, join_list, path = self.setup_joins(
field_list, self.get_meta(),
self.get_initial_alias(), reuse)
targets, _, join_list = self.trim_joins(sources, join_list, path)
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
if reuse is not None:
reuse.update(join_list)
col = targets[0].get_col(join_list[-1], sources[0])
return col
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
return Ref(name, self.annotation_select[name])
else:
return self.annotation_select[name]
else:
field_list = name.split(LOOKUP_SEP)
field, sources, opts, join_list, path = self.setup_joins(
field_list, self.get_meta(),
self.get_initial_alias(), reuse)
targets, _, join_list = self.trim_joins(sources, join_list, path)
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
if reuse is not None:
reuse.update(join_list)
col = targets[0].get_col(join_list[-1], sources[0])
return col
def resolve_ref(self, name, allow_joins=True, reuse=None, summarize=False):
if not allow_joins and LOOKUP_SEP in name:
raise FieldError("Joined field references are not permitted in this query")
if name in self.annotations:
if summarize:
# Summarize currently means we are doing an aggregate() query
# which is executed as a wrapped subquery if any of the
# aggregate() elements reference an existing annotation. In
# that case we need to return a Ref to the subquery's annotation.
return Ref(name, self.annotation_select[name])
else:
return self.annotation_select[name]
else:
field_list = name.split(LOOKUP_SEP)
field, sources, opts, join_list, path = self.setup_joins(
field_list, self.get_meta(),
self.get_initial_alias(), reuse)
targets, _, join_list = self.trim_joins(sources, join_list, path)
if len(targets) > 1:
raise FieldError("Referencing multicolumn fields with F() objects "
"isn't supported")
if reuse is not None:
reuse.update(join_list)
col = targets[0].get_col(join_list[-1], sources[0])
return col
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, Col):
# Reference to column. Make sure the referenced column
# is selected.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_exprs.append(Ref(col_alias, expr))
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, Col):
# Reference to column. Make sure the referenced column
# is selected.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_exprs.append(Ref(col_alias, expr))
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, Col):
# Reference to column. Make sure the referenced column
# is selected.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_exprs.append(Ref(col_alias, expr))
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, Col):
# Reference to column. Make sure the referenced column
# is selected.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_exprs.append(Ref(col_alias, expr))
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, Col):
# Reference to column. Make sure the referenced column
# is selected.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_exprs.append(Ref(col_alias, expr))
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
# FIXME: These conditions are fairly arbitrary. Identify a better
# method of having expressions decide which code path they should
# take.
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, (WhereNode, Lookup)):
# Decompose the subexpressions further. The code here is
# copied from the else clause, but this condition must appear
# before the contains_aggregate/is_summary condition below.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
elif isinstance(expr, Col) or (expr.contains_aggregate and not expr.is_summary):
# Reference to column. Make sure the referenced column
# is selected.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_exprs.append(Ref(col_alias, expr))
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
def rewrite_cols(self, annotation, col_cnt):
# We must make sure the inner query has the referred columns in it.
# If we are aggregating over an annotation, then Django uses Ref()
# instances to note this. However, if we are annotating over a column
# of a related model, then it might be that column isn't part of the
# SELECT clause of the inner query, and we must manually make sure
# the column is selected. An example case is:
# .aggregate(Sum('author__awards'))
# Resolving this expression results in a join to author, but there
# is no guarantee the awards column of author is in the select clause
# of the query. Thus we must manually add the column to the inner
# query.
orig_exprs = annotation.get_source_expressions()
new_exprs = []
for expr in orig_exprs:
# FIXME: These conditions are fairly arbitrary. Identify a better
# method of having expressions decide which code path they should
# take.
if isinstance(expr, Ref):
# Its already a Ref to subquery (see resolve_ref() for
# details)
new_exprs.append(expr)
elif isinstance(expr, (WhereNode, Lookup)):
# Decompose the subexpressions further. The code here is
# copied from the else clause, but this condition must appear
# before the contains_aggregate/is_summary condition below.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
elif isinstance(expr, Col) or (expr.contains_aggregate and not expr.is_summary):
# Reference to column. Make sure the referenced column
# is selected.
col_cnt += 1
col_alias = '__col%d' % col_cnt
self.annotations[col_alias] = expr
self.append_annotation_mask([col_alias])
new_exprs.append(Ref(col_alias, expr))
else:
# Some other expression not referencing database values
# directly. Its subexpression might contain Cols.
new_expr, col_cnt = self.rewrite_cols(expr, col_cnt)
new_exprs.append(new_expr)
annotation.set_source_expressions(new_exprs)
return annotation, col_cnt
