# -*- coding: utf-8 -*-
#
# Copyright (C) 2016 Andi Albrecht, albrecht.andi@gmail.com
#
# This module is part of python-sqlparse and is released under
# the BSD License: https://opensource.org/licenses/BSD-3-Clause
"""This module contains classes representing syntactical elements of SQL."""
from __future__ import print_function
import re
from sqlparse import tokens as T
from sqlparse.compat import string_types, text_type, unicode_compatible
from sqlparse.utils import imt, remove_quotes
@unicode_compatible
class Token(object):
"""Base class for all other classes in this module.
It represents a single token and has two instance attributes:
``value`` is the unchange value of the token and ``ttype`` is
the type of the token.
"""
__slots__ = ('value', 'ttype', 'parent', 'normalized', 'is_keyword',
'is_group', 'is_whitespace')
def __init__(self, ttype, value):
value = text_type(value)
self.value = value
self.ttype = ttype
self.parent = None
self.is_group = False
self.is_keyword = ttype in T.Keyword
self.is_whitespace = self.ttype in T.Whitespace
self.normalized = value.upper() if self.is_keyword else value
def __str__(self):
return self.value
# Pending tokenlist __len__ bug fix
# def __len__(self):
# return len(self.value)
def __repr__(self):
cls = self._get_repr_name()
value = self._get_repr_value()
q = u'"' if value.startswith("'") and value.endswith("'") else u"'"
return u"<{cls} {q}{value}{q} at 0x{id:2X}>".format(
id=id(self), **locals())
def _get_repr_name(self):
return str(self.ttype).split('.')[-1]
def _get_repr_value(self):
raw = text_type(self)
if len(raw) > 7:
raw = raw[:6] + '...'
return re.sub(r'\s+', ' ', raw)
def flatten(self):
"""Resolve subgroups."""
yield self
def match(self, ttype, values, regex=False):
"""Checks whether the token matches the given arguments.
*ttype* is a token type. If this token doesn't match the given token
type.
*values* is a list of possible values for this token. The values
are OR'ed together so if only one of the values matches ``True``
is returned. Except for keyword tokens the comparison is
case-sensitive. For convenience it's ok to pass in a single string.
If *regex* is ``True`` (default is ``False``) the given values are
treated as regular expressions.
"""
type_matched = self.ttype is ttype
if not type_matched or values is None:
return type_matched
if isinstance(values, string_types):
values = (values,)
if regex:
# TODO: Add test for regex with is_keyboard = false
flag = re.IGNORECASE if self.is_keyword else 0
values = (re.compile(v, flag) for v in values)
for pattern in values:
if pattern.search(self.normalized):
return True
return False
if self.is_keyword:
values = (v.upper() for v in values)
return self.normalized in values
def within(self, group_cls):
"""Returns ``True`` if this token is within *group_cls*.
Use this method for example to check if an identifier is within
a function: ``t.within(sql.Function)``.
"""
parent = self.parent
while parent:
if isinstance(parent, group_cls):
return True
parent = parent.parent
return False
def is_child_of(self, other):
"""Returns ``True`` if this token is a direct child of *other*."""
return self.parent == other
def has_ancestor(self, other):
"""Returns ``True`` if *other* is in this tokens ancestry."""
parent = self.parent
while parent:
if parent == other:
return True
parent = parent.parent
return False
@unicode_compatible
class TokenList(Token):
"""A group of tokens.
It has an additional instance attribute ``tokens`` which holds a
list of child-tokens.
"""
__slots__ = 'tokens'
def __init__(self, tokens=None):
self.tokens = tokens or []
[setattr(token, 'parent', self) for token in tokens]
super(TokenList, self).__init__(None, text_type(self))
self.is_group = True
def __str__(self):
return u''.join(token.value for token in self.flatten())
# weird bug
# def __len__(self):
# return len(self.tokens)
def __iter__(self):
return iter(self.tokens)
def __getitem__(self, item):
return self.tokens[item]
def _get_repr_name(self):
return type(self).__name__
def _pprint_tree(self, max_depth=None, depth=0, f=None):
"""Pretty-print the object tree."""
indent = u' | ' * depth
for idx, token in enumerate(self.tokens):
cls = token._get_repr_name()
value = token._get_repr_value()
q = u'"' if value.startswith("'") and value.endswith("'") else u"'"
print(u"{indent}{idx:2d} {cls} {q}{value}{q}"
.format(**locals()), file=f)
if token.is_group and (max_depth is None or depth < max_depth):
token._pprint_tree(max_depth, depth + 1, f)
def get_token_at_offset(self, offset):
"""Returns the token that is on position offset."""
idx = 0
for token in self.flatten():
end = idx + len(token.value)
if idx <= offset < end:
return token
idx = end
def flatten(self):
"""Generator yielding ungrouped tokens.
This method is recursively called for all child tokens.
"""
for token in self.tokens:
if token.is_group:
for item in token.flatten():
yield item
else:
yield token
def get_sublists(self):
for token in self.tokens:
if token.is_group:
yield token
@property
def _groupable_tokens(self):
return self.tokens
def _token_matching(self, funcs, start=0, end=None, reverse=False):
"""next token that match functions"""
if start is None:
return None
if not isinstance(funcs, (list, tuple)):
funcs = (funcs,)
if reverse:
assert end is None
for idx in range(start - 2, -1, -1):
token = self.tokens[idx]
for func in funcs:
if func(token):
return idx, token
else:
for idx, token in enumerate(self.tokens[start:end], start=start):
for func in funcs:
if func(token):
return idx, token
return None, None
def token_first(self, skip_ws=True, skip_cm=False):
"""Returns the first child token.
If *skip_ws* is ``True`` (the default), whitespace
tokens are ignored.
if *skip_cm* is ``True`` (default: ``False``), comments are
ignored too.
"""
# this on is inconsistent, using Comment instead of T.Comment...
funcs = lambda tk: not ((skip_ws and tk.is_whitespace) or
(skip_cm and imt(tk, t=T.Comment, i=Comment)))
return self._token_matching(funcs)[1]
def token_next_by(self, i=None, m=None, t=None, idx=-1, end=None):
funcs = lambda tk: imt(tk, i, m, t)
idx += 1
return self._token_matching(funcs, idx, end)
def token_not_matching(self, funcs, idx):
funcs = (funcs,) if not isinstance(funcs, (list, tuple)) else funcs
funcs = [lambda tk: not func(tk) for func in funcs]
return self._token_matching(funcs, idx)
def token_matching(self, funcs, idx):
return self._token_matching(funcs, idx)[1]
def token_prev(self, idx, skip_ws=True, skip_cm=False):
"""Returns the previous token relative to *idx*.
If *skip_ws* is ``True`` (the default) whitespace tokens are ignored.
If *skip_cm* is ``True`` comments are ignored.
``None`` is returned if there's no previous token.
"""
return self.token_next(idx, skip_ws, skip_cm, _reverse=True)
# TODO: May need to re-add default value to idx
def token_next(self, idx, skip_ws=True, skip_cm=False, _reverse=False):
"""Returns the next token relative to *idx*.
If *skip_ws* is ``True`` (the default) whitespace tokens are ignored.
If *skip_cm* is ``True`` comments are ignored.
``None`` is returned if there's no next token.
"""
if idx is None:
return None, None
idx += 1 # alot of code usage current pre-compensates for this
funcs = lambda tk: not ((skip_ws and tk.is_whitespace) or
(skip_cm and imt(tk, t=T.Comment, i=Comment)))
return self._token_matching(funcs, idx, reverse=_reverse)
def token_index(self, token, start=0):
"""Return list index of token."""
start = start if isinstance(start, int) else self.token_index(start)
return start + self.tokens[start:].index(token)
def group_tokens(self, grp_cls, start, end, include_end=True,
extend=False):
"""Replace tokens by an instance of *grp_cls*."""
start_idx = start
start = self.tokens[start_idx]
end_idx = end + include_end
# will be needed later for new group_clauses
# while skip_ws and tokens and tokens[-1].is_whitespace:
# tokens = tokens[:-1]
if extend and isinstance(start, grp_cls):
subtokens = self.tokens[start_idx + 1:end_idx]
grp = start
grp.tokens.extend(subtokens)
del self.tokens[start_idx + 1:end_idx]
grp.value = text_type(start)
else:
subtokens = self.tokens[start_idx:end_idx]
grp = grp_cls(subtokens)
self.tokens[start_idx:end_idx] = [grp]
grp.parent = self
for token in subtokens:
token.parent = grp
return grp
def insert_before(self, where, token):
"""Inserts *token* before *where*."""
if not isinstance(where, int):
where = self.token_index(where)
token.parent = self
self.tokens.insert(where, token)
def insert_after(self, where, token, skip_ws=True):
"""Inserts *token* after *where*."""
if not isinstance(where, int):
where = self.token_index(where)
nidx, next_ = self.token_next(where, skip_ws=skip_ws)
token.parent = self
if next_ is None:
self.tokens.append(token)
else:
self.tokens.insert(nidx, token)
def has_alias(self):
"""Returns ``True`` if an alias is present."""
return self.get_alias() is not None
def get_alias(self):
"""Returns the alias for this identifier or ``None``."""
# "name AS alias"
kw_idx, kw = self.token_next_by(m=(T.Keyword, 'AS'))
if kw is not None:
return self._get_first_name(kw_idx + 1, keywords=True)
# "name alias" or "complicated column expression alias"
_, ws = self.token_next_by(t=T.Whitespace)
if len(self.tokens) > 2 and ws is not None:
return self._get_first_name(reverse=True)
def get_name(self):
"""Returns the name of this identifier.
This is either it's alias or it's real name. The returned valued can
be considered as the name under which the object corresponding to
this identifier is known within the current statement.
"""
return self.get_alias() or self.get_real_name()
def get_real_name(self):
"""Returns the real name (object name) of this identifier."""
# a.b
dot_idx, _ = self.token_next_by(m=(T.Punctuation, '.'))
return self._get_first_name(dot_idx)
def get_parent_name(self):
"""Return name of the parent object if any.
A parent object is identified by the first occuring dot.
"""
dot_idx, _ = self.token_next_by(m=(T.Punctuation, '.'))
_, prev_ = self.token_prev(dot_idx)
return remove_quotes(prev_.value) if prev_ is not None else None
def _get_first_name(self, idx=None, reverse=False, keywords=False):
"""Returns the name of the first token with a name"""
tokens = self.tokens[idx:] if idx else self.tokens
tokens = reversed(tokens) if reverse else tokens
types = [T.Name, T.Wildcard, T.String.Symbol]
if keywords:
types.append(T.Keyword)
for token in tokens:
if token.ttype in types:
return remove_quotes(token.value)
elif isinstance(token, (Identifier, Function)):
return token.get_name()
class Statement(TokenList):
"""Represents a SQL statement."""
def get_type(self):
"""Returns the type of a statement.
The returned value is a string holding an upper-cased reprint of
the first DML or DDL keyword. If the first token in this group
isn't a DML or DDL keyword "UNKNOWN" is returned.
Whitespaces and comments at the beginning of the statement
are ignored.
"""
first_token = self.token_first(skip_cm=True)
if first_token is None:
# An "empty" statement that either has not tokens at all
# or only whitespace tokens.
return 'UNKNOWN'
elif first_token.ttype in (T.Keyword.DML, T.Keyword.DDL):
return first_token.normalized
elif first_token.ttype == T.Keyword.CTE:
# The WITH keyword should be followed by either an Identifier or
# an IdentifierList containing the CTE definitions; the actual
# DML keyword (e.g. SELECT, INSERT) will follow next.
fidx = self.token_index(first_token)
tidx, token = self.token_next(fidx, skip_ws=True)
if isinstance(token, (Identifier, IdentifierList)):
_, dml_keyword = self.token_next(tidx, skip_ws=True)
if dml_keyword.ttype == T.Keyword.DML:
return dml_keyword.normalized
# Hmm, probably invalid syntax, so return unknown.
return 'UNKNOWN'
class Identifier(TokenList):
"""Represents an identifier.
Identifiers may have aliases or typecasts.
"""
def is_wildcard(self):
"""Return ``True`` if this identifier contains a wildcard."""
_, token = self.token_next_by(t=T.Wildcard)
return token is not None
def get_typecast(self):
"""Returns the typecast or ``None`` of this object as a string."""
midx, marker = self.token_next_by(m=(T.Punctuation, '::'))
nidx, next_ = self.token_next(midx, skip_ws=False)
return next_.value if next_ else None
def get_ordering(self):
"""Returns the ordering or ``None`` as uppercase string."""
_, ordering = self.token_next_by(t=T.Keyword.Order)
return ordering.normalized if ordering else None
def get_array_indices(self):
"""Returns an iterator of index token lists"""
for token in self.tokens:
if isinstance(token, SquareBrackets):
# Use [1:-1] index to discard the square brackets
yield token.tokens[1:-1]
class IdentifierList(TokenList):
"""A list of :class:`~sqlparse.sql.Identifier`\'s."""
def get_identifiers(self):
"""Returns the identifiers.
Whitespaces and punctuations are not included in this generator.
"""
for token in self.tokens:
if not (token.is_whitespace or token.match(T.Punctuation, ',')):
yield token
class Parenthesis(TokenList):
"""Tokens between parenthesis."""
M_OPEN = T.Punctuation, '('
M_CLOSE = T.Punctuation, ')'
@property
def _groupable_tokens(self):
return self.tokens[1:-1]
class SquareBrackets(TokenList):
"""Tokens between square brackets"""
M_OPEN = T.Punctuation, '['
M_CLOSE = T.Punctuation, ']'
@property
def _groupable_tokens(self):
return self.tokens[1:-1]
class Assignment(TokenList):
"""An assignment like 'var := val;'"""
class If(TokenList):
"""An 'if' clause with possible 'else if' or 'else' parts."""
M_OPEN = T.Keyword, 'IF'
M_CLOSE = T.Keyword, 'END IF'
class For(TokenList):
"""A 'FOR' loop."""
M_OPEN = T.Keyword, ('FOR', 'FOREACH')
M_CLOSE = T.Keyword, 'END LOOP'
class Comparison(TokenList):
"""A comparison used for example in WHERE clauses."""
@property
def left(self):
return self.tokens[0]
@property
def right(self):
return self.tokens[-1]
class Comment(TokenList):
"""A comment."""
def is_multiline(self):
return self.tokens and self.tokens[0].ttype == T.Comment.Multiline
class Where(TokenList):
"""A WHERE clause."""
M_OPEN = T.Keyword, 'WHERE'
M_CLOSE = T.Keyword, ('ORDER', 'GROUP', 'LIMIT', 'UNION', 'EXCEPT',
'HAVING', 'RETURNING', 'INTO')
class Case(TokenList):
"""A CASE statement with one or more WHEN and possibly an ELSE part."""
M_OPEN = T.Keyword, 'CASE'
M_CLOSE = T.Keyword, 'END'
def get_cases(self, skip_ws=False):
"""Returns a list of 2-tuples (condition, value).
If an ELSE exists condition is None.
"""
CONDITION = 1
VALUE = 2
ret = []
mode = CONDITION
for token in self.tokens:
# Set mode from the current statement
if token.match(T.Keyword, 'CASE'):
continue
elif skip_ws and token.ttype in T.Whitespace:
continue
elif token.match(T.Keyword, 'WHEN'):
ret.append(([], []))
mode = CONDITION
elif token.match(T.Keyword, 'THEN'):
mode = VALUE
elif token.match(T.Keyword, 'ELSE'):
ret.append((None, []))
mode = VALUE
elif token.match(T.Keyword, 'END'):
mode = None
# First condition without preceding WHEN
if mode and not ret:
ret.append(([], []))
# Append token depending of the current mode
if mode == CONDITION:
ret[-1][0].append(token)
elif mode == VALUE:
ret[-1][1].append(token)
# Return cases list
return ret
class Function(TokenList):
"""A function or procedure call."""
def get_parameters(self):
"""Return a list of parameters."""
parenthesis = self.tokens[-1]
for token in parenthesis.tokens:
if isinstance(token, IdentifierList):
return token.get_identifiers()
elif imt(token, i=(Function, Identifier), t=T.Literal):
return [token, ]
return []
class Begin(TokenList):
"""A BEGIN/END block."""
M_OPEN = T.Keyword, 'BEGIN'
M_CLOSE = T.Keyword, 'END'
class Operation(TokenList):
"""Grouping of operations"""
