| # Copyright 2016 The Chromium Authors. All rights reserved. |
| # Use of this source code is govered by a BSD-style |
| # license that can be found in the LICENSE file or at |
| # https://developers.google.com/open-source/licenses/bsd |
| |
| """Convert a user's issue search AST into SQL clauses. |
| |
| The main query is done on the Issues table. |
| + Some simple conditions are implemented as WHERE conditions on the Issue |
| table rows. These are generated by the _Compare() function. |
| + More complex conditions are implemented via a "LEFT JOIN ... ON ..." clause |
| plus a check in the WHERE clause to select only rows where the join's ON |
| condition was satisfied. These are generated by appending a clause to |
| the left_joins list plus calling _CompareAlreadyJoined(). Each such left |
| join defines a unique alias to keep it separate from other conditions. |
| |
| The functions that generate SQL snippets need to insert table names, column |
| names, alias names, and value placeholders into the generated string. These |
| functions use the string format() method and the "{varname}" syntax to avoid |
| confusion with the "%s" syntax used for SQL value placeholders. |
| """ |
| |
| import logging |
| |
| from framework import sql |
| from proto import ast_pb2 |
| from proto import tracker_pb2 |
| from services import tracker_fulltext |
| |
| |
| NATIVE_SEARCHABLE_FIELDS = { |
| 'id': 'local_id', |
| 'stars': 'star_count', |
| 'attachments': 'attachment_count', |
| 'opened': 'opened', |
| 'closed': 'closed', |
| 'modified': 'modified', |
| 'spam': 'is_spam' |
| } |
| |
| |
| def BuildSQLQuery(query_ast): |
| """Translate the user's query into an SQL query. |
| |
| Args: |
| query_ast: user query abstract syntax tree parsed by query2ast.py. |
| |
| Returns: |
| A pair of lists (left_joins, where) to use when building the SQL SELECT |
| statement. Each of them is a list of (str, [val, ...]) pairs. |
| """ |
| left_joins = [] |
| where = [] |
| # TODO(jrobbins): Handle "OR" in queries. For now, we just process the |
| # first conjunction and assume that it is the only one. |
| assert len(query_ast.conjunctions) == 1, 'TODO(jrobbins) handle "OR" queries' |
| conj = query_ast.conjunctions[0] |
| |
| for cond_num, cond in enumerate(conj.conds): |
| cond_left_joins, cond_where = _ProcessCond(cond_num, cond) |
| left_joins.extend(cond_left_joins) |
| where.extend(cond_where) |
| |
| return left_joins, where |
| |
| |
| def _ProcessBlockedOnIDCond(cond, alias, _user_alias): |
| """Convert a blockedon_id=issue_id cond to SQL.""" |
| return _GetBlockIDCond(cond, alias, blocking_id=False) |
| |
| |
| def _ProcessBlockingIDCond(cond, alias, _user_alias): |
| """Convert a blocking_id:1,2 cond to SQL.""" |
| return _GetBlockIDCond(cond, alias, blocking_id=True) |
| |
| |
| def _GetBlockIDCond(cond, alias, blocking_id=False): |
| """Convert either a blocking_id or blockedon_id cond to SQL. |
| |
| If blocking_id is False then it is treated as a blockedon_id request, |
| otherwise it is treated as a blocking_id request. |
| """ |
| matching_issue_col = 'issue_id' if blocking_id else 'dst_issue_id' |
| ret_issue_col = 'dst_issue_id' if blocking_id else 'issue_id' |
| |
| kind_cond_str, kind_cond_args = _Compare( |
| alias, ast_pb2.QueryOp.EQ, tracker_pb2.FieldTypes.STR_TYPE, 'kind', |
| ['blockedon']) |
| left_joins = [( |
| ('IssueRelation AS {alias} ON Issue.id = {alias}.%s AND ' |
| '{kind_cond}' % ret_issue_col).format( |
| alias=alias, kind_cond=kind_cond_str), kind_cond_args)] |
| |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| if field_values: |
| where = [_Compare( |
| alias, ast_pb2.QueryOp.EQ, field_type, matching_issue_col, |
| field_values)] |
| else: |
| # If no field values are specified display all issues which have the |
| # property. |
| where = [_CompareAlreadyJoined(alias, cond.op, ret_issue_col)] |
| |
| return left_joins, where |
| |
| |
| def _GetFieldTypeAndValues(cond): |
| """Returns the field type and values to use from the condition. |
| |
| This function should be used when we do not know what values are present on |
| the condition. Eg: cond.int_values could be set if ast2ast.py preprocessing is |
| first done. If that preprocessing is not done then str_values could be set |
| instead. |
| If both int values and str values exist on the condition then the int values |
| are returned. |
| """ |
| if cond.int_values: |
| return tracker_pb2.FieldTypes.INT_TYPE, cond.int_values |
| else: |
| return tracker_pb2.FieldTypes.STR_TYPE, cond.str_values |
| |
| |
| def _ProcessOwnerCond(cond, alias, _user_alias): |
| """Convert an owner:substring cond to SQL.""" |
| left_joins = [( |
| 'User AS {alias} ON (Issue.owner_id = {alias}.user_id ' |
| 'OR Issue.derived_owner_id = {alias}.user_id)'.format( |
| alias=alias), [])] |
| where = [_Compare(alias, cond.op, tracker_pb2.FieldTypes.STR_TYPE, 'email', |
| cond.str_values)] |
| |
| return left_joins, where |
| |
| |
| def _ProcessOwnerIDCond(cond, _alias, _user_alias): |
| """Convert an owner_id=user_id cond to SQL.""" |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| explicit_str, explicit_args = _Compare( |
| 'Issue', cond.op, field_type, 'owner_id', field_values) |
| derived_str, derived_args = _Compare( |
| 'Issue', cond.op, field_type, 'derived_owner_id', field_values) |
| if cond.op in (ast_pb2.QueryOp.NE, ast_pb2.QueryOp.NOT_TEXT_HAS): |
| where = [(explicit_str, explicit_args), (derived_str, derived_args)] |
| else: |
| if cond.op == ast_pb2.QueryOp.IS_NOT_DEFINED: |
| op = ' AND ' |
| else: |
| op = ' OR ' |
| where = [ |
| ('(' + explicit_str + op + derived_str + ')', |
| explicit_args + derived_args)] |
| |
| return [], where |
| |
| |
| def _ProcessReporterCond(cond, alias, _user_alias): |
| """Convert a reporter:substring cond to SQL.""" |
| left_joins = [( |
| 'User AS {alias} ON Issue.reporter_id = {alias}.user_id'.format( |
| alias=alias), [])] |
| where = [_Compare(alias, cond.op, tracker_pb2.FieldTypes.STR_TYPE, 'email', |
| cond.str_values)] |
| |
| return left_joins, where |
| |
| |
| def _ProcessReporterIDCond(cond, _alias, _user_alias): |
| """Convert a reporter_ID=user_id cond to SQL.""" |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| where = [_Compare( |
| 'Issue', cond.op, field_type, 'reporter_id', field_values)] |
| return [], where |
| |
| |
| def _ProcessCcCond(cond, alias, user_alias): |
| """Convert a cc:substring cond to SQL.""" |
| email_cond_str, email_cond_args = _Compare( |
| user_alias, cond.op, tracker_pb2.FieldTypes.STR_TYPE, 'email', |
| cond.str_values) |
| # Note: email_cond_str will have parens, if needed. |
| left_joins = [( |
| '(Issue2Cc AS {alias} JOIN User AS {user_alias} ' |
| 'ON {alias}.cc_id = {user_alias}.user_id AND {email_cond}) ' |
| 'ON Issue.id = {alias}.issue_id AND ' |
| 'Issue.shard = {alias}.issue_shard'.format( |
| alias=alias, user_alias=user_alias, email_cond=email_cond_str), |
| email_cond_args)] |
| where = [_CompareAlreadyJoined(user_alias, cond.op, 'email')] |
| |
| return left_joins, where |
| |
| |
| def _ProcessCcIDCond(cond, alias, _user_alias): |
| """Convert a cc_id=user_id cond to SQL.""" |
| join_str = ( |
| 'Issue2Cc AS {alias} ON Issue.id = {alias}.issue_id AND ' |
| 'Issue.shard = {alias}.issue_shard'.format( |
| alias=alias)) |
| if cond.op in (ast_pb2.QueryOp.IS_DEFINED, ast_pb2.QueryOp.IS_NOT_DEFINED): |
| left_joins = [(join_str, [])] |
| else: |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| cond_str, cond_args = _Compare( |
| alias, ast_pb2.QueryOp.EQ, field_type, 'cc_id', field_values) |
| left_joins = [(join_str + ' AND ' + cond_str, cond_args)] |
| |
| where = [_CompareAlreadyJoined(alias, cond.op, 'cc_id')] |
| return left_joins, where |
| |
| |
| def _ProcessStarredByCond(cond, alias, user_alias): |
| """Convert a starredby:substring cond to SQL.""" |
| email_cond_str, email_cond_args = _Compare( |
| user_alias, cond.op, tracker_pb2.FieldTypes.STR_TYPE, 'email', |
| cond.str_values) |
| # Note: email_cond_str will have parens, if needed. |
| left_joins = [( |
| '(IssueStar AS {alias} JOIN User AS {user_alias} ' |
| 'ON {alias}.user_id = {user_alias}.user_id AND {email_cond}) ' |
| 'ON Issue.id = {alias}.issue_id'.format( |
| alias=alias, user_alias=user_alias, email_cond=email_cond_str), |
| email_cond_args)] |
| where = [_CompareAlreadyJoined(user_alias, cond.op, 'email')] |
| |
| return left_joins, where |
| |
| |
| def _ProcessStarredByIDCond(cond, alias, _user_alias): |
| """Convert a starredby_id=user_id cond to SQL.""" |
| join_str = 'IssueStar AS {alias} ON Issue.id = {alias}.issue_id'.format( |
| alias=alias) |
| if cond.op in (ast_pb2.QueryOp.IS_DEFINED, ast_pb2.QueryOp.IS_NOT_DEFINED): |
| left_joins = [(join_str, [])] |
| else: |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| cond_str, cond_args = _Compare( |
| alias, ast_pb2.QueryOp.EQ, field_type, 'user_id', field_values) |
| left_joins = [(join_str + ' AND ' + cond_str, cond_args)] |
| |
| where = [_CompareAlreadyJoined(alias, cond.op, 'user_id')] |
| return left_joins, where |
| |
| |
| def _ProcessCommentByCond(cond, alias, user_alias): |
| """Convert a commentby:substring cond to SQL.""" |
| email_cond_str, email_cond_args = _Compare( |
| user_alias, cond.op, tracker_pb2.FieldTypes.STR_TYPE, 'email', |
| cond.str_values) |
| # Note: email_cond_str will have parens, if needed. |
| left_joins = [( |
| '(Comment AS {alias} JOIN User AS {user_alias} ' |
| 'ON {alias}.commenter_id = {user_alias}.user_id AND {email_cond}) ' |
| 'ON Issue.id = {alias}.issue_id'.format( |
| alias=alias, user_alias=user_alias, email_cond=email_cond_str), |
| email_cond_args)] |
| where = [_CompareAlreadyJoined(user_alias, cond.op, 'email')] |
| |
| return left_joins, where |
| |
| |
| def _ProcessCommentByIDCond(cond, alias, _user_alias): |
| """Convert a commentby_id=user_id cond to SQL.""" |
| left_joins = [( |
| 'Comment AS {alias} ON Issue.id = {alias}.issue_id'.format( |
| alias=alias), [])] |
| if cond.op in (ast_pb2.QueryOp.IS_DEFINED, ast_pb2.QueryOp.IS_NOT_DEFINED): |
| where = [_CompareAlreadyJoined(alias, cond.op, 'commenter_id')] |
| else: |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| where = [_Compare(alias, cond.op, field_type, 'commenter_id', field_values)] |
| |
| return left_joins, where |
| |
| |
| def _ProcessStatusIDCond(cond, _alias, _user_alias): |
| """Convert a status_id=ID cond to SQL.""" |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| explicit_str, explicit_args = _Compare( |
| 'Issue', cond.op, field_type, 'status_id', field_values) |
| derived_str, derived_args = _Compare( |
| 'Issue', cond.op, field_type, 'derived_status_id', field_values) |
| if cond.op in (ast_pb2.QueryOp.IS_NOT_DEFINED, ast_pb2.QueryOp.NE): |
| where = [(explicit_str, explicit_args), (derived_str, derived_args)] |
| else: |
| where = [ |
| ('(' + explicit_str + ' OR ' + derived_str + ')', |
| explicit_args + derived_args)] |
| |
| return [], where |
| |
| |
| def _ProcessLabelIDCond(cond, alias, _user_alias): |
| """Convert a label_id=ID cond to SQL.""" |
| join_str = ( |
| 'Issue2Label AS {alias} ON Issue.id = {alias}.issue_id AND ' |
| 'Issue.shard = {alias}.issue_shard'.format(alias=alias)) |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| cond_str, cond_args = _Compare( |
| alias, ast_pb2.QueryOp.EQ, field_type, 'label_id', field_values) |
| left_joins = [(join_str + ' AND ' + cond_str, cond_args)] |
| where = [_CompareAlreadyJoined(alias, cond.op, 'label_id')] |
| return left_joins, where |
| |
| |
| def _ProcessComponentIDCond(cond, alias, _user_alias): |
| """Convert a component_id=ID cond to SQL.""" |
| # This is a built-in field, so it shadows any other fields w/ the same name. |
| join_str = ( |
| 'Issue2Component AS {alias} ON Issue.id = {alias}.issue_id AND ' |
| 'Issue.shard = {alias}.issue_shard'.format(alias=alias)) |
| if cond.op in (ast_pb2.QueryOp.IS_DEFINED, ast_pb2.QueryOp.IS_NOT_DEFINED): |
| left_joins = [(join_str, [])] |
| else: |
| field_type, field_values = _GetFieldTypeAndValues(cond) |
| cond_str, cond_args = _Compare( |
| alias, ast_pb2.QueryOp.EQ, field_type, 'component_id', field_values) |
| left_joins = [(join_str + ' AND ' + cond_str, cond_args)] |
| |
| where = [_CompareAlreadyJoined(alias, cond.op, 'component_id')] |
| return left_joins, where |
| |
| |
| def _ProcessCustomFieldCond(cond, alias, user_alias): |
| """Convert a custom field cond to SQL.""" |
| # TODO(jrobbins): handle ambiguous field names that map to multiple |
| # field definitions, especially for cross-project search. |
| field_def = cond.field_defs[0] |
| val_type = field_def.field_type |
| |
| join_str = ( |
| 'Issue2FieldValue AS {alias} ON Issue.id = {alias}.issue_id AND ' |
| 'Issue.shard = {alias}.issue_shard AND ' |
| '{alias}.field_id = %s'.format(alias=alias)) |
| left_joins = [(join_str, [field_def.field_id])] |
| if val_type == tracker_pb2.FieldTypes.INT_TYPE: |
| where = [_Compare(alias, cond.op, val_type, 'int_value', cond.int_values)] |
| elif val_type == tracker_pb2.FieldTypes.STR_TYPE: |
| where = [_Compare(alias, cond.op, val_type, 'str_value', cond.str_values)] |
| elif val_type == tracker_pb2.FieldTypes.USER_TYPE: |
| if cond.int_values or cond.op in ( |
| ast_pb2.QueryOp.IS_DEFINED, ast_pb2.QueryOp.IS_NOT_DEFINED): |
| where = [_Compare(alias, cond.op, val_type, 'user_id', cond.int_values)] |
| else: |
| email_cond_str, email_cond_args = _Compare( |
| user_alias, cond.op, val_type, 'email', cond.str_values) |
| left_joins.append(( |
| 'User AS {user_alias} ON {alias}.user_id = {user_alias}.user_id ' |
| 'AND {email_cond}'.format( |
| alias=alias, user_alias=user_alias, email_cond=email_cond_str), |
| email_cond_args)) |
| where = [_CompareAlreadyJoined(user_alias, cond.op, 'email')] |
| |
| return left_joins, where |
| |
| |
| def _ProcessAttachmentCond(cond, alias, _user_alias): |
| """Convert has:attachment and -has:attachment cond to SQL.""" |
| if cond.op in (ast_pb2.QueryOp.IS_DEFINED, ast_pb2.QueryOp.IS_NOT_DEFINED): |
| left_joins = [] |
| where = [_Compare('Issue', cond.op, tracker_pb2.FieldTypes.INT_TYPE, |
| 'attachment_count', cond.int_values)] |
| else: |
| field_def = cond.field_defs[0] |
| val_type = field_def.field_type |
| left_joins = [ |
| ('Attachment AS {alias} ON Issue.id = {alias}.issue_id AND ' |
| '{alias}.deleted = %s'.format(alias=alias), |
| [False])] |
| where = [_Compare(alias, cond.op, val_type, 'filename', cond.str_values)] |
| |
| return left_joins, where |
| |
| |
| _PROCESSORS = { |
| 'owner': _ProcessOwnerCond, |
| 'owner_id': _ProcessOwnerIDCond, |
| 'reporter': _ProcessReporterCond, |
| 'reporter_id': _ProcessReporterIDCond, |
| 'cc': _ProcessCcCond, |
| 'cc_id': _ProcessCcIDCond, |
| 'starredby': _ProcessStarredByCond, |
| 'starredby_id': _ProcessStarredByIDCond, |
| 'commentby': _ProcessCommentByCond, |
| 'commentby_id': _ProcessCommentByIDCond, |
| 'status_id': _ProcessStatusIDCond, |
| 'label_id': _ProcessLabelIDCond, |
| 'component_id': _ProcessComponentIDCond, |
| 'blockedon_id': _ProcessBlockedOnIDCond, |
| 'blocking_id': _ProcessBlockingIDCond, |
| 'attachment': _ProcessAttachmentCond, |
| } |
| |
| |
| def _ProcessCond(cond_num, cond): |
| """Translate one term of the user's search into an SQL query. |
| |
| Args: |
| cond_num: integer cond number used to make distinct local variable names. |
| cond: user query cond parsed by query2ast.py. |
| |
| Returns: |
| A pair of lists (left_joins, where) to use when building the SQL SELECT |
| statement. Each of them is a list of (str, [val, ...]) pairs. |
| """ |
| alias = 'Cond%d' % cond_num |
| user_alias = 'User%d' % cond_num |
| # Note: a condition like [x=y] has field_name "x", there may be multiple |
| # field definitions that match "x", but they will all have field_name "x". |
| field_def = cond.field_defs[0] |
| assert all(field_def.field_name == fd.field_name for fd in cond.field_defs) |
| |
| if field_def.field_name in NATIVE_SEARCHABLE_FIELDS: |
| col = NATIVE_SEARCHABLE_FIELDS[field_def.field_name] |
| where = [_Compare( |
| 'Issue', cond.op, field_def.field_type, col, |
| cond.str_values or cond.int_values)] |
| return [], where |
| |
| elif field_def.field_name in _PROCESSORS: |
| proc = _PROCESSORS[field_def.field_name] |
| return proc(cond, alias, user_alias) |
| |
| elif field_def.field_id: # it is a search on a custom field |
| return _ProcessCustomFieldCond(cond, alias, user_alias) |
| |
| elif (field_def.field_name in tracker_fulltext.ISSUE_FULLTEXT_FIELDS or |
| field_def.field_name == 'any_field'): |
| pass # handled by full-text search. |
| |
| else: |
| logging.error('untranslated search cond %r', cond) |
| |
| return [], [] |
| |
| |
| def _Compare(alias, op, val_type, col, vals): |
| """Return an SQL comparison for the given values. For use in WHERE or ON. |
| |
| Args: |
| alias: String name of the table or alias defined in a JOIN clause. |
| op: One of the operators defined in ast_pb2.py. |
| val_type: One of the value types defined in ast_pb2.py. |
| col: string column name to compare to vals. |
| vals: list of values that the user is searching for. |
| |
| Returns: |
| (cond_str, cond_args) where cond_str is a SQL condition that may contain |
| some %s placeholders, and cond_args is the list of values that fill those |
| placeholders. If the condition string contains any AND or OR operators, |
| the whole expression is put inside parens. |
| |
| Raises: |
| NoPossibleResults: The user's query is impossible to ever satisfy, e.g., |
| it requires matching an empty set of labels. |
| """ |
| vals_ph = sql.PlaceHolders(vals) |
| if col in ['label', 'status', 'email']: |
| alias_col = 'LOWER(%s.%s)' % (alias, col) |
| else: |
| alias_col = '%s.%s' % (alias, col) |
| |
| def Fmt(cond_str): |
| return cond_str.format(alias_col=alias_col, vals_ph=vals_ph) |
| |
| no_value = (0 if val_type in [tracker_pb2.FieldTypes.DATE_TYPE, |
| tracker_pb2.FieldTypes.INT_TYPE] else '') |
| if op == ast_pb2.QueryOp.IS_DEFINED: |
| return Fmt('({alias_col} IS NOT NULL AND {alias_col} != %s)'), [no_value] |
| if op == ast_pb2.QueryOp.IS_NOT_DEFINED: |
| return Fmt('({alias_col} IS NULL OR {alias_col} = %s)'), [no_value] |
| |
| if val_type in [tracker_pb2.FieldTypes.DATE_TYPE, |
| tracker_pb2.FieldTypes.INT_TYPE]: |
| if op == ast_pb2.QueryOp.TEXT_HAS: |
| op = ast_pb2.QueryOp.EQ |
| if op == ast_pb2.QueryOp.NOT_TEXT_HAS: |
| op = ast_pb2.QueryOp.NE |
| |
| if op == ast_pb2.QueryOp.EQ: |
| if not vals: |
| raise NoPossibleResults('Column %s has no possible value' % alias_col) |
| elif len(vals) == 1: |
| cond_str = Fmt('{alias_col} = %s') |
| else: |
| cond_str = Fmt('{alias_col} IN ({vals_ph})') |
| return cond_str, vals |
| |
| if op == ast_pb2.QueryOp.NE: |
| if not vals: |
| return 'TRUE', [] # a no-op that matches every row. |
| elif len(vals) == 1: |
| comp = Fmt('{alias_col} != %s') |
| else: |
| comp = Fmt('{alias_col} NOT IN ({vals_ph})') |
| return '(%s IS NULL OR %s)' % (alias_col, comp), vals |
| |
| # Note: These operators do not support quick-OR |
| val = vals[0] |
| |
| if op == ast_pb2.QueryOp.GT: |
| return Fmt('{alias_col} > %s'), [val] |
| if op == ast_pb2.QueryOp.LT: |
| return Fmt('{alias_col} < %s'), [val] |
| if op == ast_pb2.QueryOp.GE: |
| return Fmt('{alias_col} >= %s'), [val] |
| if op == ast_pb2.QueryOp.LE: |
| return Fmt('{alias_col} <= %s'), [val] |
| |
| if op == ast_pb2.QueryOp.TEXT_MATCHES: |
| return Fmt('{alias_col} LIKE %s'), [val] |
| if op == ast_pb2.QueryOp.NOT_TEXT_MATCHES: |
| return Fmt('({alias_col} IS NULL OR {alias_col} NOT LIKE %s)'), [val] |
| |
| if op == ast_pb2.QueryOp.TEXT_HAS: |
| return Fmt('{alias_col} LIKE %s'), ['%' + val + '%'] |
| if op == ast_pb2.QueryOp.NOT_TEXT_HAS: |
| return (Fmt('({alias_col} IS NULL OR {alias_col} NOT LIKE %s)'), |
| ['%' + val + '%']) |
| |
| logging.error('unknown op: %r', op) |
| |
| |
| def _CompareAlreadyJoined(alias, op, col): |
| """Return a WHERE clause comparison that checks that a join succeeded.""" |
| def Fmt(cond_str): |
| return cond_str.format(alias_col='%s.%s' % (alias, col)) |
| |
| if op in (ast_pb2.QueryOp.EQ, ast_pb2.QueryOp.TEXT_HAS, |
| ast_pb2.QueryOp.TEXT_MATCHES, ast_pb2.QueryOp.IS_DEFINED): |
| return Fmt('{alias_col} IS NOT NULL'), [] |
| |
| if op in (ast_pb2.QueryOp.NE, ast_pb2.QueryOp.NOT_TEXT_HAS, |
| ast_pb2.QueryOp.NOT_TEXT_MATCHES, |
| ast_pb2.QueryOp.IS_NOT_DEFINED): |
| return Fmt('{alias_col} IS NULL'), [] |
| |
| logging.error('unknown op: %r', op) |
| |
| |
| class Error(Exception): |
| """Base class for errors from this module.""" |
| |
| |
| class NoPossibleResults(Error): |
| """The query could never match any rows from the database, so don't try..""" |