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ae01f49 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 | import sqlparse
from collections import namedtuple
from sqlparse.sql import IdentifierList, Identifier, Function
from sqlparse.tokens import Keyword, DML, Punctuation
TableReference = namedtuple(
"TableReference", ["schema", "name", "alias", "is_function"]
)
TableReference.ref = property(
lambda self: self.alias or (
self.name
if self.name.islower() or self.name[0] == '"'
else '"' + self.name + '"'
)
)
# This code is borrowed from sqlparse example script.
# <url>
def is_subselect(parsed):
if not parsed.is_group:
return False
for item in parsed.tokens:
if item.ttype is DML and item.value.upper() in (
"SELECT",
"INSERT",
"UPDATE",
"CREATE",
"DELETE",
):
return True
return False
def _identifier_is_function(identifier):
return any(isinstance(t, Function) for t in identifier.tokens)
def extract_from_part(parsed, stop_at_punctuation=True):
tbl_prefix_seen = False
for item in parsed.tokens:
if tbl_prefix_seen:
if is_subselect(item):
yield from extract_from_part(item, stop_at_punctuation)
elif stop_at_punctuation and item.ttype is Punctuation:
return
# An incomplete nested select won't be recognized correctly as a
# sub-select. eg: 'SELECT * FROM (SELECT id FROM user'. This causes
# the second FROM to trigger this elif condition resulting in a
# `return`. So we need to ignore the keyword if the keyword
# FROM.
# Also 'SELECT * FROM abc JOIN def' will trigger this elif
# condition. So we need to ignore the keyword JOIN and its variants
# INNER JOIN, FULL OUTER JOIN, etc.
elif (
item.ttype is Keyword and
item.value.upper() != "FROM" and
(not item.value.upper().endswith("JOIN"))
):
tbl_prefix_seen = False
else:
yield item
elif item.ttype is Keyword or item.ttype is Keyword.DML:
item_val = item.value.upper()
if item_val in (
"COPY",
"FROM",
"INTO",
"UPDATE",
"TABLE",
) or item_val.endswith("JOIN"):
tbl_prefix_seen = True
# 'SELECT a, FROM abc' will detect FROM as part of the column list.
# So this check here is necessary.
elif isinstance(item, IdentifierList):
for identifier in item.get_identifiers():
if identifier.ttype is Keyword and \
identifier.value.upper() == "FROM":
tbl_prefix_seen = True
break
def extract_table_identifiers(token_stream, allow_functions=True):
"""yields tuples of TableReference namedtuples"""
# We need to do some massaging of the names because postgres is case-
# insensitive and '"Foo"' is not the same table as 'Foo' (while 'foo' is)
def parse_identifier(item):
name = item.get_real_name()
schema_name = item.get_parent_name()
alias = item.get_alias()
if not name:
schema_name = None
name = item.get_name()
alias = alias or name
schema_quoted = schema_name and item.value[0] == '"'
if schema_name and not schema_quoted:
schema_name = schema_name.lower()
quote_count = item.value.count('"')
name_quoted = quote_count > 2 or (quote_count and not schema_quoted)
alias_quoted = alias and item.value[-1] == '"'
if alias_quoted or name_quoted and not alias and name.islower():
alias = '"' + (alias or name) + '"'
if name and not name_quoted and not name.islower():
if not alias:
alias = name
name = name.lower()
return schema_name, name, alias
try:
for item in token_stream:
if isinstance(item, IdentifierList):
for identifier in item.get_identifiers():
# Sometimes Keywords (such as FROM ) are classified as
# identifiers which don't have the get_real_name() method.
try:
schema_name = identifier.get_parent_name()
real_name = identifier.get_real_name()
is_function = allow_functions and \
_identifier_is_function(identifier)
except AttributeError:
continue
if real_name:
yield TableReference(
schema_name, real_name, identifier.get_alias(),
is_function
)
elif isinstance(item, Identifier):
schema_name, real_name, alias = parse_identifier(item)
is_function = allow_functions and _identifier_is_function(item)
yield TableReference(schema_name, real_name, alias,
is_function)
elif isinstance(item, Function):
schema_name, real_name, alias = parse_identifier(item)
yield TableReference(None, real_name, alias, allow_functions)
except StopIteration:
return
# extract_tables is inspired from examples in the sqlparse lib.
def extract_tables(sql):
"""Extract the table names from an SQL statment.
Returns a list of TableReference namedtuples
"""
parsed = sqlparse.parse(sql)
if not parsed:
return ()
# INSERT statements must stop looking for tables at the sign of first
# Punctuation. eg: INSERT INTO abc (col1, col2) VALUES (1, 2)
# abc is the table name, but if we don't stop at the first lparen, then
# we'll identify abc, col1 and col2 as table names.
insert_stmt = parsed[0].token_first().value.lower() == "insert"
stream = extract_from_part(parsed[0], stop_at_punctuation=insert_stmt)
# Kludge: sqlparse mistakenly identifies insert statements as
# function calls due to the parenthesized column list, e.g. interprets
# "insert into foo (bar, baz)" as a function call to foo with arguments
# (bar, baz). So don't allow any identifiers in insert statements
# to have is_function=True
identifiers = extract_table_identifiers(stream,
allow_functions=not insert_stmt)
# In the case 'sche.<cursor>', we get an empty TableReference; remove that
return tuple(i for i in identifiers if i.name)
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