"""
sqlobject.sqlbuilder
--------------------
:author: Ian Bicking <ianb@colorstudy.com>
Builds SQL expressions from normal Python expressions.
Disclaimer
----------
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
Instructions
------------
To begin a SQL expression, you must use some sort of SQL object -- a
field, table, or SQL statement (``SELECT``, ``INSERT``, etc.) You can
then use normal operators, with the exception of: `and`, `or`, `not`,
and `in`. You can use the `AND`, `OR`, `NOT`, and `IN` functions
instead, or you can also use `&`, `|`, and `~` for `and`, `or`, and
`not` respectively (however -- the precidence for these operators
doesn't work as you would want, so you must use many parenthesis).
To create a sql field, table, or constant/function, use the namespaces
`table`, `const`, and `func`. For instance, ``table.address`` refers
to the ``address`` table, and ``table.address.state`` refers to the
``state`` field in the address table. ``const.NULL`` is the ``NULL``
SQL constant, and ``func.NOW()`` is the ``NOW()`` function call
(`const` and `func` are actually identicle, but the two names are
provided for clarity). Once you create this object, expressions
formed with it will produce SQL statements.
The ``sqlrepr(obj)`` function gets the SQL representation of these
objects, as well as the proper SQL representation of basic Python
types (None==NULL).
There are a number of DB-specific SQL features that this does not
implement. There are a bunch of normal ANSI features also not present
-- particularly left joins, among others. You may wish to only use
this to generate ``WHERE`` clauses.
See the bottom of this module for some examples, and run it (i.e.
``python sql.py``) to see the results of those examples.
"""
########################################
## Constants
########################################
import fnmatch
import operator
import re
import threading
import types
import weakref
import classregistry
from converters import sqlrepr,registerConverter
class VersionError(Exception):
pass
class NoDefault:
pass
class SQLObjectState(object):
def __init__(self, soObject):
self.soObject = weakref.proxy(soObject)
safeSQLRE = re.compile(r'^[a-zA-Z_][a-zA-Z0-9_\.]*$')
def sqlIdentifier(obj):
# some db drivers return unicode column names
return isinstance(obj, basestring) and bool(safeSQLRE.search(obj.strip()))
def execute(expr, executor):
if hasattr(expr, 'execute'):
return expr.execute(executor)
else:
return expr
########################################
## Expression generation
########################################
class SQLExpression:
def __add__(self, other):
return SQLOp("+", self, other)
def __radd__(self, other):
return SQLOp("+", other, self)
def __sub__(self, other):
return SQLOp("-", self, other)
def __rsub__(self, other):
return SQLOp("-", other, self)
def __mul__(self, other):
return SQLOp("*", self, other)
def __rmul__(self, other):
return SQLOp("*", other, self)
def __div__(self, other):
return SQLOp("/", self, other)
def __rdiv__(self, other):
return SQLOp("/", other, self)
def __pos__(self):
return SQLPrefix("+", self)
def __neg__(self):
return SQLPrefix("-", self)
def __pow__(self, other):
return SQLConstant("POW")(self, other)
def __rpow__(self, other):
return SQLConstant("POW")(other, self)
def __abs__(self):
return SQLConstant("ABS")(self)
def __mod__(self, other):
return SQLConstant("MOD")(self, other)
def __rmod__(self, other):
return SQLConstant("MOD")(other, self)
def __lt__(self, other):
return SQLOp("<", self, other)
def __le__(self, other):
return SQLOp("<=", self, other)
def __gt__(self, other):
return SQLOp(">", self, other)
def __ge__(self, other):
return SQLOp(">=", self, other)
def __eq__(self, other):
if other is None:
return ISNULL(self)
else:
return SQLOp("=", self, other)
def __ne__(self, other):
if other is None:
return ISNOTNULL(self)
else:
return SQLOp("<>", self, other)
def __and__(self, other):
return SQLOp("AND", self, other)
def __rand__(self, other):
return SQLOp("AND", other, self)
def __or__(self, other):
return SQLOp("OR", self, other)
def __ror__(self, other):
return SQLOp("OR", other, self)
def __invert__(self):
return SQLPrefix("NOT", self)
def __call__(self, *args):
return SQLCall(self, args)
def __repr__(self):
try:
return self.__sqlrepr__(None)
except AssertionError:
return '<%s %s>' % (
self.__class__.__name__, hex(id(self))[2:])
def __str__(self):
return repr(self)
def __cmp__(self, other):
raise VersionError, "Python 2.1+ required"
def __rcmp__(self, other):
raise VersionError, "Python 2.1+ required"
def startswith(self, s):
return STARTSWITH(self, s)
def endswith(self, s):
return ENDSWITH(self, s)
def contains(self, s):
return CONTAINSSTRING(self, s)
def components(self):
return []
def tablesUsed(self, db):
return self.tablesUsedSet(db)
def tablesUsedSet(self, db):
tables = set()
for table in self.tablesUsedImmediate():
if hasattr(table, '__sqlrepr__'):
table = sqlrepr(table, db)
tables.add(table)
for component in self.components():
tables.update(tablesUsedSet(component, db))
return tables
def tablesUsedImmediate(self):
return []
#######################################
# Converter for SQLExpression instances
#######################################
def SQLExprConverter(value, db):
return value.__sqlrepr__()
registerConverter(SQLExpression, SQLExprConverter)
def tablesUsedSet(obj, db):
if hasattr(obj, "tablesUsedSet"):
return obj.tablesUsedSet(db)
else:
return {}
operatorMap = {
"+": operator.add,
"/": operator.div,
"-": operator.sub,
"*": operator.mul,
"<": operator.lt,
"<=": operator.le,
"=": operator.eq,
"!=": operator.ne,
">=": operator.ge,
">": operator.gt,
"IN": operator.contains,
"IS": operator.eq,
}
class SQLOp(SQLExpression):
def __init__(self, op, expr1, expr2):
self.op = op.upper()
self.expr1 = expr1
self.expr2 = expr2
def __sqlrepr__(self, db):
s1 = sqlrepr(self.expr1, db)
s2 = sqlrepr(self.expr2, db)
if s1[0] != '(' and s1 != 'NULL':
s1 = '(' + s1 + ')'
if s2[0] != '(' and s2 != 'NULL':
s2 = '(' + s2 + ')'
return "(%s %s %s)" % (s1, self.op, s2)
def components(self):
return [self.expr1, self.expr2]
def execute(self, executor):
if self.op == "AND":
return execute(self.expr1, executor) \
and execute(self.expr2, executor)
elif self.op == "OR":
return execute(self.expr1, executor) \
or execute(self.expr2, executor)
else:
return operatorMap[self.op.upper()](execute(self.expr1, executor),
execute(self.expr2, executor))
registerConverter(SQLOp, SQLExprConverter)
class SQLCall(SQLExpression):
def __init__(self, expr, args):
self.expr = expr
self.args = args
def __sqlrepr__(self, db):
return "%s%s" % (sqlrepr(self.expr, db), sqlrepr(self.args, db))
def components(self):
return [self.expr] + list(self.args)
def execute(self, executor):
raise ValueError, "I don't yet know how to locally execute functions"
registerConverter(SQLCall, SQLExprConverter)
class SQLPrefix(SQLExpression):
def __init__(self, prefix, expr):
self.prefix = prefix
self.expr = expr
def __sqlrepr__(self, db):
return "%s %s" % (self.prefix, sqlrepr(self.expr, db))
def components(self):
return [self.expr]
def execute(self, executor):
expr = execute(self.expr, executor)
if prefix == "+":
return expr
elif prefix == "-":
return -expr
elif prefix.upper() == "NOT":
return not expr
registerConverter(SQLPrefix, SQLExprConverter)
class SQLConstant(SQLExpression):
def __init__(self, const):
self.const = const
def __sqlrepr__(self, db):
return self.const
def execute(self, executor):
raise ValueError, "I don't yet know how to execute SQL constants"
registerConverter(SQLConstant, SQLExprConverter)
class SQLTrueClauseClass(SQLExpression):
def __sqlrepr__(self, db):
return "1 = 1"
def execute(self, executor):
return 1
SQLTrueClause = SQLTrueClauseClass()
registerConverter(SQLTrueClauseClass, SQLExprConverter)
########################################
## Namespaces
########################################
class Field(SQLExpression):
def __init__(self, tableName, fieldName):
self.tableName = tableName
self.fieldName = fieldName
def __sqlrepr__(self, db):
return self.tableName + "." + self.fieldName
def tablesUsedImmediate(self):
return [self.tableName]
def execute(self, executor):
return executor.field(self.tableName, self.fieldName)
class SQLObjectField(Field):
def __init__(self, tableName, fieldName, original, soClass, column):
Field.__init__(self, tableName, fieldName)
self.original = original
self.soClass = soClass
self.column = column
def _from_python(self, value):
column = self.column
if not isinstance(value, SQLExpression) and column and column.from_python:
value = column.from_python(value, SQLObjectState(self.soClass))
return value
def __eq__(self, other):
if other is None:
return ISNULL(self)
other = self._from_python(other)
return SQLOp('=', self, other)
def __ne__(self, other):
if other is None:
return ISNOTNULL(self)
other = self._from_python(other)
return SQLOp('<>', self, other)
def startswith(self, s):
s = self._from_python(s)
return STARTSWITH(self, s)
def endswith(self, s):
s = self._from_python(s)
return ENDSWITH(self, s)
def contains(self, s):
s = self._from_python(s)
return CONTAINSSTRING(self, s)
registerConverter(SQLObjectField, SQLExprConverter)
class Table(SQLExpression):
FieldClass = Field
def __init__(self, tableName):
self.tableName = tableName
def __getattr__(self, attr):
if attr.startswith('__'):
raise AttributeError
return self.FieldClass(self.tableName, attr)
def __sqlrepr__(self, db):
if isinstance(self.tableName, str):
return self.tableName
return sqlrepr(self.tableName, db)
def execute(self, executor):
raise ValueError, "Tables don't have values"
class SQLObjectTable(Table):
FieldClass = SQLObjectField
def __init__(self, soClass):
self.soClass = soClass
assert soClass.sqlmeta.table, (
"Bad table name in class %r: %r"
% (soClass, soClass.sqlmeta.table))
Table.__init__(self, soClass.sqlmeta.table)
def __getattr__(self, attr):
if attr.startswith('__'):
raise AttributeError
if attr == 'id':
return self._getattrFromID(attr)
elif attr in self.soClass.sqlmeta.columns:
column = self.soClass.sqlmeta.columns[attr]
return self._getattrFromColumn(column, attr)
elif attr+'ID' in [k for (k, v) in self.soClass.sqlmeta.columns.items() if v.foreignKey]:
attr += 'ID'
column = self.soClass.sqlmeta.columns[attr]
return self._getattrFromColumn(column, attr)
else:
raise AttributeError("%s instance has no attribute '%s'" % (self.soClass.__name__, attr))
def _getattrFromID(self, attr):
return self.FieldClass(self.tableName, self.soClass.sqlmeta.idName, attr, self.soClass, None)
def _getattrFromColumn(self, column, attr):
return self.FieldClass(self.tableName, column.dbName, attr, self.soClass, column)
class SQLObjectTableWithJoins(SQLObjectTable):
def __getattr__(self, attr):
if attr+'ID' in [k for (k,v) in self.soClass.sqlmeta.columns.items() if v.foreignKey]:
column = self.soClass.sqlmeta.columns[attr+'ID']
return self._getattrFromForeignKey(column, attr)
elif attr in [x.joinMethodName for x in self.soClass.sqlmeta.joins]:
join = [x for x in self.soClass.sqlmeta.joins if x.joinMethodName == attr][0]
return self._getattrFromJoin(join, attr)
else:
return SQLObjectTable.__getattr__(self, attr)
def _getattrFromForeignKey(self, column, attr):
ret = getattr(self, column.name) == \
getattr(self.soClass, '_SO_class_'+column.foreignKey).q.id
return ret
def _getattrFromJoin(self, join, attr):
if hasattr(join, 'otherColumn'):
return AND(join.otherClass.q.id == Field(join.intermediateTable, join.otherColumn),
Field(join.intermediateTable, join.joinColumn) == self.soClass.q.id)
else:
return getattr(join.otherClass.q, join.joinColumn)==self.soClass.q.id
class TableSpace:
TableClass = Table
def __getattr__(self, attr):
if attr.startswith('__'):
raise AttributeError
return self.TableClass(attr)
class ConstantSpace:
def __getattr__(self, attr):
if attr.startswith('__'):
raise AttributeError
return SQLConstant(attr)
########################################
## Table aliases
########################################
class AliasField(Field):
def __init__(self, tableName, fieldName, alias, aliasTable):
Field.__init__(self, tableName, fieldName)
self.alias = alias
self.aliasTable = aliasTable
def __sqlrepr__(self, db):
fieldName = self.fieldName
if isinstance(fieldName, SQLExpression):
fieldName = sqlrepr(fieldName, db)
return self.alias + "." + fieldName
def tablesUsedImmediate(self):
return [self.aliasTable]
class AliasTable(Table):
as_string = '' # set it to "AS" if your database requires it
FieldClass = AliasField
_alias_lock = threading.Lock()
_alias_counter = 0
def __init__(self, table, alias=None):
if hasattr(table, "sqlmeta"):
tableName = SQLConstant(table.sqlmeta.table)
elif isinstance(table, (Select,Union)):
assert alias is not None, "Alias name cannot be constructed from Select instances, please provide 'alias' kw."
tableName = Subquery('', table)
table = None
else:
tableName = SQLConstant(table)
table = None
Table.__init__(self, tableName)
self.table = table
if alias is None:
self._alias_lock.acquire()
try:
AliasTable._alias_counter += 1
alias = "%s_alias%d" % (tableName, AliasTable._alias_counter)
finally:
self._alias_lock.release()
self.alias = alias
def __getattr__(self, attr):
if attr.startswith('__'):
raise AttributeError
if self.table:
attr = getattr(self.table.q, attr).fieldName
return self.FieldClass(self.tableName, attr, self.alias, self)
def __sqlrepr__(self, db):
return "%s %s %s" % (sqlrepr(self.tableName, db), self.as_string, self.alias)
class Alias(SQLExpression):
def __init__(self, table, alias=None):
self.q = AliasTable(table, alias)
def __sqlrepr__(self, db):
return sqlrepr(self.q, db)
def components(self):
return [self.q]
class Union(SQLExpression):
def __init__(self, *tables):
tabs = []
for t in tables:
if not isinstance(t, SQLExpression) and hasattr(t, 'sqlmeta'):
t = t.sqlmeta.table
if isinstance(t, Alias):
t = t.q
if isinstance(t, Table):
t = t.tableName
if not isinstance(t, SQLExpression):
t = SQLConstant(t.sqlmeta.table)
tabs.append(t)
self.tables = tabs
def __sqlrepr__(self, db):
return " UNION ".join([str(sqlrepr(t, db)) for t in self.tables])
########################################
## SQL Statements
########################################
class Select(SQLExpression):
def __init__(self, items=NoDefault, where=NoDefault, groupBy=NoDefault,
having=NoDefault, orderBy=NoDefault, limit=NoDefault,
join=NoDefault, lazyColumns=False, distinct=False,
start=0, end=None, reversed=False, forUpdate=False,
clause=NoDefault, staticTables=NoDefault, distinctOn=NoDefault):
self.ops = {}
if not isinstance(items, (list, tuple, types.GeneratorType)):
items = [items]
if clause is NoDefault and where is not NoDefault:
clause = where
if staticTables is NoDefault:
staticTables = []
self.ops['items'] = items
self.ops['clause'] = clause
self.ops['groupBy'] = groupBy
self.ops['having'] = having
self.ops['orderBy'] = orderBy
self.ops['limit'] = limit
self.ops['join'] = join
self.ops['lazyColumns'] = lazyColumns
self.ops['distinct'] = distinct
self.ops['distinctOn'] = distinctOn
self.ops['start'] = start
self.ops['end'] = end
self.ops['reversed'] = reversed
self.ops['forUpdate'] = forUpdate
self.ops['staticTables'] = staticTables
def clone(self, **newOps):
ops = self.ops.copy()
ops.update(newOps)
return self.__class__(**ops)
def newItems(self, items):
return self.clone(items=items)
def newClause(self, new_clause):
return self.clone(clause=new_clause)
def orderBy(self, orderBy):
return self.clone(orderBy=orderBy)
def unlimited(self):
return self.clone(limit=NoDefault, start=0, end=None)
def limit(self, limit):
self.clone(limit=limit)
def lazyColumns(self, value):
return self.clone(lazyColumns=value)
def reversed(self):
return self.clone(reversed=not self.ops.get('reversed', False))
def distinct(self):
return self.clone(distinct=True)
def filter(self, filter_clause):
if filter_clause is None:
# None doesn't filter anything, it's just a no-op:
return self
clause = self.ops['clause']
if isinstance(clause, basestring):
clause = SQLConstant('(%s)' % clause)
if clause == SQLTrueClause:
newClause = filter_clause
else:
newClause = AND(clause, filter_clause)
return self.newClause(newClause)
def __sqlrepr__(self, db):
select = "SELECT"
if self.ops['distinct']:
select += " DISTINCT"
if self.ops['distinctOn'] is not NoDefault:
select += " ON(%s)" % sqlrepr(self.ops['distinctOn'], db)
if not self.ops['lazyColumns']:
select += " %s" % ", ".join([str(sqlrepr(v, db)) for v in self.ops['items']])
else:
select += " %s" % sqlrepr(self.ops['items'][0], db)
join = []
join_str = ''
if self.ops['join'] is not NoDefault and self.ops['join'] is not None:
_join = self.ops['join']
if isinstance(_join, str):
join_str = " " + _join
elif isinstance(_join, SQLJoin):
join.append(_join)
else:
join.extend(_join)
tables = set()
for x in self.ops['staticTables']:
if isinstance(x, SQLExpression):
x = sqlrepr(x, db)
tables.add(x)
things = list(self.ops['items']) + join
if self.ops['clause'] is not NoDefault:
things.append(self.ops['clause'])
for thing in things:
if isinstance(thing, SQLExpression):
tables.update(tablesUsedSet(thing, db))
for j in join:
t1, t2 = sqlrepr(j.table1, db), sqlrepr(j.table2, db)
if t1 in tables: tables.remove(t1)
if t2 in tables: tables.remove(t2)
if tables:
select += " FROM %s" % ", ".join(tables)
elif join:
select += " FROM"
tablesYet = tables
for j in join:
if tablesYet and j.table1:
sep = ", "
else:
sep = " "
select += sep + sqlrepr(j, db)
tablesYet = True
if join_str:
select += join_str
if self.ops['clause'] is not NoDefault:
select += " WHERE %s" % sqlrepr(self.ops['clause'], db)
if self.ops['groupBy'] is not NoDefault:
groupBy = sqlrepr(self.ops['groupBy'], db)
if isinstance(self.ops['groupBy'], (list, tuple)):
groupBy = groupBy[1:-1] # Remove parens
select += " GROUP BY %s" % groupBy
if self.ops['having'] is not NoDefault:
select += " HAVING %s" % sqlrepr(self.ops['having'], db)
if self.ops['orderBy'] is not NoDefault and self.ops['orderBy'] is not None:
orderBy = self.ops['orderBy']
if self.ops['reversed']:
reverser = DESC
else:
reverser = lambda x: x
if isinstance(orderBy, (list, tuple)):
select += " ORDER BY %s" % ", ".join([sqlrepr(reverser(x), db) for x in orderBy])
else:
select += " ORDER BY %s" % sqlrepr(reverser(orderBy), db)
start, end = self.ops['start'], self.ops['end']
if self.ops['limit'] is not NoDefault:
end = start + self.ops['limit']
if start or end:
from dbconnection import dbConnectionForScheme
select = dbConnectionForScheme(db)._queryAddLimitOffset(select, start, end)
if self.ops['forUpdate']:
select += " FOR UPDATE"
return select
registerConverter(Select, SQLExprConverter)
class Insert(SQLExpression):
def __init__(self, table, valueList=None, values=None, template=NoDefault):
self.template = template
self.table = table
if valueList:
if values:
raise TypeError, "You may only give valueList *or* values"
self.valueList = valueList
else:
self.valueList = [values]
def __sqlrepr__(self, db):
if not self.valueList:
return ''
insert = "INSERT INTO %s" % self.table
allowNonDict = True
template = self.template
if (template is NoDefault) and isinstance(self.valueList[0], dict):
template = self.valueList[0].keys()
allowNonDict = False
if template is not NoDefault:
insert += " (%s)" % ", ".join(template)
insert += " VALUES "
listToJoin = []
listToJoin_app = listToJoin.append
for value in self.valueList:
if isinstance(value, dict):
if template is NoDefault:
raise TypeError, "You can't mix non-dictionaries with dictionaries in an INSERT if you don't provide a template (%s)" % repr(value)
value = dictToList(template, value)
elif not allowNonDict:
raise TypeError, "You can't mix non-dictionaries with dictionaries in an INSERT if you don't provide a template (%s)" % repr(value)
listToJoin_app("(%s)" % ", ".join([sqlrepr(v, db) for v in value]))
insert = "%s%s" % (insert, ", ".join(listToJoin))
return insert
registerConverter(Insert, SQLExprConverter)
def dictToList(template, dict):
list = []
for key in template:
list.append(dict[key])
if len(dict.keys()) > len(template):
raise TypeError, "Extra entries in dictionary that aren't asked for in template (template=%s, dict=%s)" % (repr(template), repr(dict))
return list
class Update(SQLExpression):
def __init__(self, table, values, template=NoDefault, where=NoDefault):
self.table = table
self.values = values
self.template = template
self.whereClause = where
def __sqlrepr__(self, db):
update = "%s %s" % (self.sqlName(), self.table)
update += " SET"
first = True
if self.template is not NoDefault:
for i in range(len(self.template)):
if first:
first = False
else:
update += ","
update += " %s=%s" % (self.template[i], sqlrepr(self.values[i], db))
else:
for key, value in self.values.items():
if first:
first = False
else:
update += ","
update += " %s=%s" % (key, sqlrepr(value, db))
if self.whereClause is not NoDefault:
update += " WHERE %s" % sqlrepr(self.whereClause, db)
return update
def sqlName(self):
return "UPDATE"
registerConverter(Update, SQLExprConverter)
class Delete(SQLExpression):
"""To be safe, this will signal an error if there is no where clause,
unless you pass in where=None to the constructor."""
def __init__(self, table, where=NoDefault):
self.table = table
if where is NoDefault:
raise TypeError, "You must give a where clause or pass in None to indicate no where clause"
self.whereClause = where
def __sqlrepr__(self, db):
whereClause = self.whereClause
if whereClause is None:
return "DELETE FROM %s" % self.table
if isinstance(whereClause, SQLExpression):
whereClause = sqlrepr(whereClause, db)
return "DELETE FROM %s WHERE %s" % (self.table, whereClause)
registerConverter(Delete, SQLExprConverter)
class Replace(Update):
def sqlName(self):
return "REPLACE"
registerConverter(Replace, SQLExprConverter)
########################################
## SQL Builtins
########################################
class DESC(SQLExpression):
def __init__(self, expr):
self.expr = expr
def __sqlrepr__(self, db):
if isinstance(self.expr, DESC):
return sqlrepr(self.expr.expr, db)
return '%s DESC' % sqlrepr(self.expr, db)
def AND(*ops):
if not ops:
return None
op1 = ops[0]
ops = ops[1:]
if ops:
return SQLOp("AND", op1, AND(*ops))
else:
return op1
def OR(*ops):
if not ops:
return None
op1 = ops[0]
ops = ops[1:]
if ops:
return SQLOp("OR", op1, OR(*ops))
else:
return op1
def NOT(op):
return SQLPrefix("NOT", op)
def _IN(item, list):
return SQLOp("IN", item, list)
def IN(item, list):
if isinstance(list, Select):
return INSubquery(item, list)
else:
return _IN(item, list)
def NOTIN(item, list):
if isinstance(list, Select):
return NOTINSubquery(item, list)
else:
return NOT(_IN(item, list))
def STARTSWITH(expr, pattern):
return LIKE(expr, _LikeQuoted(pattern) + '%', escape='\\')
def ENDSWITH(expr, pattern):
return LIKE(expr, '%' + _LikeQuoted(pattern), escape='\\')
def CONTAINSSTRING(expr, pattern):
return LIKE(expr, '%' + _LikeQuoted(pattern) + '%', escape='\\')
def ISNULL(expr):
return SQLOp("IS", expr, None)
def ISNOTNULL(expr):
return SQLOp("IS NOT", expr, None)
class ColumnAS(SQLOp):
''' Just like SQLOp('AS', expr, name) except without the parentheses '''
def __init__(self, expr, name):
if isinstance(name, basestring):
name = SQLConstant(name)
SQLOp.__init__(self, 'AS', expr, name)
def __sqlrepr__(self, db):
return "%s %s %s" % (sqlrepr(self.expr1, db), self.op, sqlrepr(self.expr2, db))
class _LikeQuoted:
# It assumes prefix and postfix are strings; usually just a percent sign.
# @@: I'm not sure what the quoting rules really are for all the
# databases
def __init__(self, expr):
self.expr = expr
self.prefix = ''
self.postfix = ''
def __radd__(self, s):
self.prefix = s + self.prefix
return self
def __add__(self, s):
self.postfix += s
return self
def __sqlrepr__(self, db):
s = self.expr
if isinstance(s, SQLExpression):
values = []
if self.prefix:
values.append("'%s'" % self.prefix)
s = _quote_like_special(sqlrepr(s, db), db)
values.append(s)
if self.postfix:
values.append("'%s'" % self.postfix)
if db == "mysql":
return "CONCAT(%s)" % ", ".join(values)
else:
return " || ".join(values)
elif isinstance(s, basestring):
s = _quote_like_special(sqlrepr(s, db)[1:-1], db)
return "'%s%s%s'" % (self.prefix, s, self.postfix)
else:
raise TypeError, "expected str, unicode or SQLExpression, got %s" % type(s)
def _quote_like_special(s, db):
if db == 'postgres':
escape = r'\\'
else:
escape = '\\'
s = s.replace('\\', r'\\').replace('%', escape+'%').replace('_', escape+'_')
return s
########################################
## SQL JOINs
########################################
class SQLJoin(SQLExpression):
def __init__(self, table1, table2, op=','):
if hasattr(table1, 'sqlmeta'):
table1 = table1.sqlmeta.table
if hasattr(table2, 'sqlmeta'):
table2 = table2.sqlmeta.table
if isinstance(table1, str):
table1 = SQLConstant(table1)
if isinstance(table2, str):
table2 = SQLConstant(table2)
self.table1 = table1
self.table2 = table2
self.op = op
def __sqlrepr__(self, db):
if self.table1:
return "%s%s %s" % (sqlrepr(self.table1, db), self.op, sqlrepr(self.table2, db))
else:
return "%s %s" % (self.op, sqlrepr(self.table2, db))
registerConverter(SQLJoin, SQLExprConverter)
def JOIN(table1, table2):
return SQLJoin(table1, table2, " JOIN")
def INNERJOIN(table1, table2):
return SQLJoin(table1, table2, " INNER JOIN")
def CROSSJOIN(table1, table2):
return SQLJoin(table1, table2, " CROSS JOIN")
def STRAIGHTJOIN(table1, table2):
return SQLJoin(table1, table2, " STRAIGHT JOIN")
def LEFTJOIN(table1, table2):
return SQLJoin(table1, table2, " LEFT JOIN")
def LEFTOUTERJOIN(table1, table2):
return SQLJoin(table1, table2, " LEFT OUTER JOIN")
def NATURALJOIN(table1, table2):
return SQLJoin(table1, table2, " NATURAL JOIN")
def NATURALLEFTJOIN(table1, table2):
return SQLJoin(table1, table2, " NATURAL LEFT JOIN")
def NATURALLEFTOUTERJOIN(table1, table2):
return SQLJoin(table1, table2, " NATURAL LEFT OUTER JOIN")
def RIGHTJOIN(table1, table2):
return SQLJoin(table1, table2, " RIGHT JOIN")
def RIGHTOUTERJOIN(table1, table2):
return SQLJoin(table1, table2, " RIGHT OUTER JOIN")
def NATURALRIGHTJOIN(table1, table2):
return SQLJoin(table1, table2, " NATURAL RIGHT JOIN")
def NATURALRIGHTOUTERJOIN(table1, table2):
return SQLJoin(table1, table2, " NATURAL RIGHT OUTER JOIN")
def FULLJOIN(table1, table2):
return SQLJoin(table1, table2, " FULL JOIN")
def FULLOUTERJOIN(table1, table2):
return SQLJoin(table1, table2, " FULL OUTER JOIN")
def NATURALFULLJOIN(table1, table2):
return SQLJoin(table1, table2, " NATURAL FULL JOIN")
def NATURALFULLOUTERJOIN(table1, table2):
return SQLJoin(table1, table2, " NATURAL FULL OUTER JOIN")
class SQLJoinConditional(SQLJoin):
"""Conditional JOIN"""
def __init__(self, table1, table2, op, on_condition=None, using_columns=None):
"""For condition you must give on_condition or using_columns but not both
on_condition can be a string or SQLExpression, for example
Table1.q.col1 == Table2.q.col2
using_columns can be a string or a list of columns, e.g.
(Table1.q.col1, Table2.q.col2)
"""
if not on_condition and not using_columns:
raise TypeError, "You must give ON condition or USING columns"
if on_condition and using_columns:
raise TypeError, "You must give ON condition or USING columns but not both"
SQLJoin.__init__(self, table1, table2, op)
self.on_condition = on_condition
self.using_columns = using_columns
def __sqlrepr__(self, db):
if self.on_condition:
on_condition = self.on_condition
if hasattr(on_condition, "__sqlrepr__"):
on_condition = sqlrepr(on_condition, db)
join = "%s %s ON %s" % (self.op, sqlrepr(self.table2, db), on_condition)
if self.table1:
join = "%s %s" % (sqlrepr(self.table1, db), join)
return join
elif self.using_columns:
using_columns = []
for col in self.using_columns:
if hasattr(col, "__sqlrepr__"):
col = sqlrepr(col, db)
using_columns.append(col)
using_columns = ", ".join(using_columns)
join = "%s %s USING (%s)" % (self.op, sqlrepr(self.table2, db), using_columns)
if self.table1:
join = "%s %s" % (sqlrepr(self.table1, db), join)
return join
else:
RuntimeError, "Impossible error"
registerConverter(SQLJoinConditional, SQLExprConverter)
def INNERJOINConditional(table1, table2, on_condition=None, using_columns=None):
return SQLJoinConditional(table1, table2, "INNER JOIN", on_condition, using_columns)
def LEFTJOINConditional(table1, table2, on_condition=None, using_columns=None):
return SQLJoinConditional(table1, table2, "LEFT JOIN", on_condition, using_columns)
def LEFTOUTERJOINConditional(table1, table2, on_condition=None, using_columns=None):
return SQLJoinConditional(table1, table2, "LEFT OUTER JOIN", on_condition, using_columns)
def RIGHTJOINConditional(table1, table2, on_condition=None, using_columns=None):
return SQLJoinConditional(table1, table2, "RIGHT JOIN", on_condition, using_columns)
def RIGHTOUTERJOINConditional(table1, table2, on_condition=None, using_columns=None):
return SQLJoinConditional(table1, table2, "RIGHT OUTER JOIN", on_condition, using_columns)
def FULLJOINConditional(table1, table2, on_condition=None, using_columns=None):
return SQLJoinConditional(table1, table2, "FULL JOIN", on_condition, using_columns)
def FULLOUTERJOINConditional(table1, table2, on_condition=None, using_columns=None):
return SQLJoinConditional(table1, table2, "FULL OUTER JOIN", on_condition, using_columns)
class SQLJoinOn(SQLJoinConditional):
"""Conditional JOIN ON"""
def __init__(self, table1, table2, op, on_condition):
SQLJoinConditional.__init__(self, table1, table2, op, on_condition)
registerConverter(SQLJoinOn, SQLExprConverter)
class SQLJoinUsing(SQLJoinConditional):
"""Conditional JOIN USING"""
def __init__(self, table1, table2, op, using_columns):
SQLJoinConditional.__init__(self, table1, table2, op, None, using_columns)
registerConverter(SQLJoinUsing, SQLExprConverter)
def INNERJOINOn(table1, table2, on_condition):
return SQLJoinOn(table1, table2, "INNER JOIN", on_condition)
def LEFTJOINOn(table1, table2, on_condition):
return SQLJoinOn(table1, table2, "LEFT JOIN", on_condition)
def LEFTOUTERJOINOn(table1, table2, on_condition):
return SQLJoinOn(table1, table2, "LEFT OUTER JOIN", on_condition)
def RIGHTJOINOn(table1, table2, on_condition):
return SQLJoinOn(table1, table2, "RIGHT JOIN", on_condition)
def RIGHTOUTERJOINOn(table1, table2, on_condition):
return SQLJoinOn(table1, table2, "RIGHT OUTER JOIN", on_condition)
def FULLJOINOn(table1, table2, on_condition):
return SQLJoinOn(table1, table2, "FULL JOIN", on_condition)
def FULLOUTERJOINOn(table1, table2, on_condition):
return SQLJoinOn(table1, table2, "FULL OUTER JOIN", on_condition)
def INNERJOINUsing(table1, table2, using_columns):
return SQLJoinUsing(table1, table2, "INNER JOIN", using_columns)
def LEFTJOINUsing(table1, table2, using_columns):
return SQLJoinUsing(table1, table2, "LEFT JOIN", using_columns)
def LEFTOUTERJOINUsing(table1, table2, using_columns):
return SQLJoinUsing(table1, table2, "LEFT OUTER JOIN", using_columns)
def RIGHTJOINUsing(table1, table2, using_columns):
return SQLJoinUsing(table1, table2, "RIGHT JOIN", using_columns)
def RIGHTOUTERJOINUsing(table1, table2, using_columns):
return SQLJoinUsing(table1, table2, "RIGHT OUTER JOIN", using_columns)
def FULLJOINUsing(table1, table2, using_columns):
return SQLJoinUsing(table1, table2, "FULL JOIN", using_columns)
def FULLOUTERJOINUsing(table1, table2, using_columns):
return SQLJoinUsing(table1, table2, "FULL OUTER JOIN", using_columns)
########################################
## Subqueries (subselects)
########################################
class OuterField(Field):
def tablesUsedImmediate(self):
return []
class OuterTable(Table):
FieldClass = OuterField
def __init__(self, table):
if hasattr(table, "sqlmeta"):
tableName = table.sqlmeta.table
else:
tableName = table
table = None
Table.__init__(self, tableName)
self.table = table
class Outer:
def __init__(self, table):
self.q = OuterTable(table)
class LIKE(SQLExpression):
op = "LIKE"
def __init__(self, expr, string, escape=None):
self.expr = expr
self.string = string
self.escape = escape
def __sqlrepr__(self, db):
escape = self.escape
like = "%s %s (%s)" % (sqlrepr(self.expr, db), self.op, sqlrepr(self.string, db))
if escape is None:
return "(%s)" % like
else:
return "(%s ESCAPE %s)" % (like, sqlrepr(escape, db))
def components(self):
return [self.expr, self.string]
def execute(self, executor):
if not hasattr(self, '_regex'):
# @@: Crude, not entirely accurate
dest = self.string
dest = dest.replace("%%", "\001")
dest = dest.replace("*", "\002")
dest = dest.replace("%", "*")
dest = dest.replace("\001", "%")
dest = dest.replace("\002", "[*]")
self._regex = re.compile(fnmatch.translate(dest), re.I)
return self._regex.search(execute(self.expr, executor))
class RLIKE(LIKE):
op = "RLIKE"
op_db = {
'firebird': 'RLIKE',
'maxdb': 'RLIKE',
'mysql': 'RLIKE',
'postgres': '~',
'sqlite': 'REGEXP'
}
def _get_op(self, db):
return self.op_db.get(db, 'LIKE')
def __sqlrepr__(self, db):
return "(%s %s (%s))" % (
sqlrepr(self.expr, db), self._get_op(db), sqlrepr(self.string, db)
)
def execute(self, executor):
self.op = self._get_op(self.db)
return LIKE.execute(self, executor)
class INSubquery(SQLExpression):
op = "IN"
def __init__(self, item, subquery):
self.item = item
self.subquery = subquery
def components(self):
return [self.item]
def __sqlrepr__(self, db):
return "%s %s (%s)" % (sqlrepr(self.item, db), self.op, sqlrepr(self.subquery, db))
class NOTINSubquery(INSubquery):
op = "NOT IN"
class Subquery(SQLExpression):
def __init__(self, op, subquery):
self.op = op
self.subquery = subquery
def __sqlrepr__(self, db):
return "%s (%s)" % (self.op, sqlrepr(self.subquery, db))
def EXISTS(subquery):
return Subquery("EXISTS", subquery)
def NOTEXISTS(subquery):
return Subquery("NOT EXISTS", subquery)
def SOME(subquery):
return Subquery("SOME", subquery)
def ANY(subquery):
return Subquery("ANY", subquery)
def ALL(subquery):
return Subquery("ALL", subquery)
####
class ImportProxyField(SQLObjectField):
def tablesUsedImmediate(self):
return [str(self.tableName)]
class ImportProxy(SQLExpression):
'''Class to be used in column definitions that rely on other tables that might
not yet be in a classregistry.
'''
FieldClass = ImportProxyField
def __init__(self, clsName, registry=None):
self.tableName = _DelayClass(self, clsName)
self.sqlmeta = _Delay_proxy(table=_DelayClass(self, clsName))
self.q = self
self.soClass = None
classregistry.registry(registry).addClassCallback(clsName,lambda foreign, me: setattr(me, 'soClass', foreign), self)
def __nonzero__(self):
return True
def __getattr__(self, attr):
if self.soClass is None:
return _Delay(self, attr)
return getattr(self.soClass.q, attr)
class _Delay(SQLExpression):
def __init__(self, proxy, attr):
self.attr = attr
self.proxy = proxy
def __sqlrepr__(self, db):
if self.proxy.soClass is None:
return '_DELAYED_' + self.attr
val = self._resolve()
if isinstance(val, SQLExpression):
val = sqlrepr(val, db)
return val
def tablesUsedImmediate(self):
return getattr(self._resolve(), 'tablesUsedImmediate', lambda: [])()
def components(self):
return getattr(self._resolve(), 'components', lambda: [])()
def _resolve(self):
return getattr(self.proxy, self.attr)
# For AliasTable etc
def fieldName(self):
class _aliasFieldName(SQLExpression):
def __init__(self, proxy):
self.proxy = proxy
def __sqlrepr__(self, db):
return self.proxy._resolve().fieldName
return _aliasFieldName(self)
fieldName = property(fieldName)
class _DelayClass(_Delay):
def _resolve(self):
return self.proxy.soClass.sqlmeta.table
class _Delay_proxy(object):
def __init__(self, **kw):
self.__dict__.update(kw)
######
########################################
## Global initializations
########################################
table = TableSpace()
const = ConstantSpace()
func = const
########################################
## Testing
########################################
if __name__ == "__main__":
tests = """
>>> AND(table.address.name == "Ian Bicking", table.address.zip > 30000)
>>> table.address.name
>>> AND(LIKE(table.address.name, "this"), IN(table.address.zip, [100, 200, 300]))
>>> Select([table.address.name, table.address.state], where=LIKE(table.address.name, "%ian%"))
>>> Select([table.user.name], where=AND(table.user.state == table.states.abbrev))
>>> Insert(table.address, [{"name": "BOB", "address": "3049 N. 18th St."}, {"name": "TIM", "address": "409 S. 10th St."}])
>>> Insert(table.address, [("BOB", "3049 N. 18th St."), ("TIM", "409 S. 10th St.")], template=('name', 'address'))
>>> Delete(table.address, where="BOB"==table.address.name)
>>> Update(table.address, {"lastModified": const.NOW()})
>>> Replace(table.address, [("BOB", "3049 N. 18th St."), ("TIM", "409 S. 10th St.")], template=('name', 'address'))
"""
for expr in tests.split('\n'):
if not expr.strip(): continue
if expr.startswith('>>> '):
expr = expr[4:]
|