dbexts.py

mallet是自然语言处理、机器学习领域的一个开源项目。

		""" display the table's primary keys """
		cur = self.begin()
		cur.primarykeys(schema, owner, table)
		self.commit(cur)
		self.display()

	def fk(self, primary_table=None, foreign_table=None, owner=None, schema=None):
		""" display the table's foreign keys """
		cur = self.begin()
		if primary_table and foreign_table:
			cur.foreignkeys(schema, owner, primary_table, schema, owner, foreign_table)
		elif primary_table:
			cur.foreignkeys(schema, owner, primary_table, schema, owner, None)
		elif foreign_table:
			cur.foreignkeys(schema, owner, None, schema, owner, foreign_table)
		self.commit(cur)
		self.display()

	def table(self, table=None, types=("TABLE",), owner=None, schema=None):
		"""If no table argument, displays a list of all tables.  If a table argument,
		displays the columns of the given table."""
		cur = self.begin()
		if table:
			cur.columns(schema, owner, table, None)
		else:
			cur.tables(schema, owner, None, types)
		self.commit(cur)
		self.display()

	def proc(self, proc=None, owner=None, schema=None):
		"""If no proc argument, displays a list of all procedures.  If a proc argument,
		displays the parameters of the given procedure."""
		cur = self.begin()
		if proc:
			cur.procedurecolumns(schema, owner, proc, None)
		else:
			cur.procedures(schema, owner, None)
		self.commit(cur)
		self.display()

	def stat(self, table, qualifier=None, owner=None, unique=0, accuracy=0):
		""" display the table's indicies """
		cur = self.begin()
		cur.statistics(qualifier, owner, table, unique, accuracy)
		self.commit(cur)
		self.display()

	def typeinfo(self, sqltype=None):
		""" display the types available for the database """
		cur = self.begin()
		cur.gettypeinfo(sqltype)
		self.commit(cur)
		self.display()

	def tabletypeinfo(self):
		""" display the table types available for the database """
		cur = self.begin()
		cur.gettabletypeinfo()
		self.commit(cur)
		self.display()

	def schema(self, table, full=0, sort=1, owner=None):
		"""Displays a Schema object for the table.  If full is true, then generates
		references to the table in addition to the standard fields.  If sort is true,
		sort all the items in the schema, else leave them in db dependent order."""
		print >> self.out, str(Schema(self, table, owner, full, sort))

	def bulkcopy(self, dst, table, include=[], exclude=[], autobatch=0, executor=executor):
		"""Returns a Bulkcopy object using the given table."""
		if type(dst) == type(""):
			dst = dbexts(dst, cfg=self.dbs)
		bcp = Bulkcopy(dst, table, include=include, exclude=exclude, autobatch=autobatch, executor=executor)
		return bcp

	def bcp(self, src, table, where='(1=1)', params=[], include=[], exclude=[], autobatch=0, executor=executor):
		"""Bulkcopy of rows from a src database to the current database for a given table and where clause."""
		if type(src) == type(""):
			src = dbexts(src, cfg=self.dbs)
		bcp = self.bulkcopy(self, table, include, exclude, autobatch, executor)
		num = bcp.transfer(src, where, params)
		return num

	def unload(self, filename, sql, delimiter=",", includeheaders=1):
		""" Unloads the delimited results of the query to the file specified, optionally including headers. """
		u = Unload(self, filename, delimiter, includeheaders)
		u.unload(sql)

class Bulkcopy:
	"""The idea for a bcp class came from http://object-craft.com.au/projects/sybase"""
	def __init__(self, dst, table, include=[], exclude=[], autobatch=0, executor=executor):
		self.dst = dst
		self.table = table
		self.total = 0
		self.rows = []
		self.autobatch = autobatch
		self.bindings = {}

		include = map(lambda x: x.lower(), include)
		exclude = map(lambda x: x.lower(), exclude)

		_verbose = self.dst.verbose
		self.dst.verbose = 0
		try:
			self.dst.table(self.table)
			if self.dst.results:
				colmap = {}
				for a in self.dst.results:
					colmap[a[3].lower()] = a[4]
				cols = self.__filter__(colmap.keys(), include, exclude)
				for a in zip(range(len(cols)), cols):
					self.bindings[a[0]] = colmap[a[1]]
				colmap = None
			else:
				cols = self.__filter__(include, include, exclude)
		finally:
			self.dst.verbose = _verbose

		self.executor = executor(table, cols)

	def __str__(self):
		return "[%s].[%s]" % (self.dst, self.table)

	def __repr__(self):
		return "[%s].[%s]" % (self.dst, self.table)

	def __getattr__(self, name):
		if name == 'columns':
			return self.executor.cols

	def __filter__(self, values, include, exclude):
		cols = map(lambda col: col.lower(), values)
		if exclude:
			cols = filter(lambda x, ex=exclude: x not in ex, cols)
		if include:
			cols = filter(lambda x, inc=include: x in inc, cols)
		return cols

	def format(self, column, type):
		self.bindings[column] = type

	def done(self):
		if len(self.rows) > 0:
			return self.batch()
		return 0

	def batch(self):
		self.executor.execute(self.dst, self.rows, self.bindings)
		cnt = len(self.rows)
		self.total += cnt
		self.rows = []
		return cnt

	def rowxfer(self, line):
		self.rows.append(line)
		if self.autobatch: self.batch()

	def transfer(self, src, where="(1=1)", params=[]):
		sql = "select %s from %s where %s" % (", ".join(self.columns), self.table, where)
		h, d = src.raw(sql, params)
		if d:
			map(self.rowxfer, d)
			return self.done()
		return 0

class Unload:
	"""Unloads a sql statement to a file with optional formatting of each value."""
	def __init__(self, db, filename, delimiter=",", includeheaders=1):
		self.db = db
		self.filename = filename
		self.delimiter = delimiter
		self.includeheaders = includeheaders
		self.formatters = {}

	def format(self, o):
		if not o:
			return ""
		o = str(o)
		if o.find(",") != -1:
			o = "\"\"%s\"\"" % (o)
		return o

	def unload(self, sql, mode="w"):
		headers, results = self.db.raw(sql)
		w = open(self.filename, mode)
		if self.includeheaders:
			w.write("%s\n" % (self.delimiter.join(map(lambda x: x[0], headers))))
		if results:
			for a in results:
				w.write("%s\n" % (self.delimiter.join(map(self.format, a))))
		w.flush()
		w.close()

class Schema:
	"""Produces a Schema object which represents the database schema for a table"""
	def __init__(self, db, table, owner=None, full=0, sort=1):
		self.db = db
		self.table = table
		self.owner = owner
		self.full = full
		self.sort = sort
		_verbose = self.db.verbose
		self.db.verbose = 0
		try:
			if table: self.computeschema()
		finally:
			self.db.verbose = _verbose

	def computeschema(self):
		self.db.table(self.table, owner=self.owner)
		self.columns = []
		# (column name, type_name, size, nullable)
		if self.db.results:
			self.columns = map(lambda x: (x[3], x[5], x[6], x[10]), self.db.results)
			if self.sort: self.columns.sort(lambda x, y: cmp(x[0], y[0]))

		self.db.fk(None, self.table)
		# (pk table name, pk column name, fk column name, fk name, pk name)
		self.imported = []
		if self.db.results:
			self.imported = map(lambda x: (x[2], x[3], x[7], x[11], x[12]), self.db.results)
			if self.sort: self.imported.sort(lambda x, y: cmp(x[2], y[2]))

		self.exported = []
		if self.full:
			self.db.fk(self.table, None)
			# (pk column name, fk table name, fk column name, fk name, pk name)
			if self.db.results:
				self.exported = map(lambda x: (x[3], x[6], x[7], x[11], x[12]), self.db.results)
				if self.sort: self.exported.sort(lambda x, y: cmp(x[1], y[1]))

		self.db.pk(self.table)
		self.primarykeys = []
		if self.db.results:
			# (column name, key_seq, pk name)
			self.primarykeys = map(lambda x: (x[3], x[4], x[5]), self.db.results)
			if self.sort: self.primarykeys.sort(lambda x, y: cmp(x[1], y[1]))

		try:
			self.indices = None
			self.db.stat(self.table)
			self.indices = []
			# (non-unique, name, type, pos, column name, asc)
			if self.db.results:
				idxdict = {}
				# mxODBC returns a row of None's, so filter it out
				idx = map(lambda x: (x[3], x[5].strip(), x[6], x[7], x[8]), filter(lambda x: x[5], self.db.results))
				def cckmp(x, y):
					c = cmp(x[1], y[1])
					if c == 0: c = cmp(x[3], y[3])
					return c
				# sort this regardless, this gets the indicies lined up
				idx.sort(cckmp)
				for a in idx:
					if not idxdict.has_key(a[1]):
						idxdict[a[1]] = []
					idxdict[a[1]].append(a)
				self.indices = idxdict.values()
				if self.sort: self.indices.sort(lambda x, y: cmp(x[0][1], y[0][1]))
		except:
			pass

	def __str__(self):
		d = []
		d.append("Table")
		d.append("  " + self.table)
		d.append("\nPrimary Keys")
		for a in self.primarykeys:
			d.append("  %s {%s}" % (a[0], a[2]))
		d.append("\nImported (Foreign) Keys")
		for a in self.imported:
			d.append("  %s (%s.%s) {%s}" % (a[2], a[0], a[1], a[3]))
		if self.full:
			d.append("\nExported (Referenced) Keys")
			for a in self.exported:
				d.append("  %s (%s.%s) {%s}" % (a[0], a[1], a[2], a[3]))
		d.append("\nColumns")
		for a in self.columns:
			nullable = choose(a[3], "nullable", "non-nullable")
			d.append("  %-20s %s(%s), %s" % (a[0], a[1], a[2], nullable))
		d.append("\nIndices")
		if self.indices is None:
			d.append(" (failed)")
		else:
			for a in self.indices:
				unique = choose(a[0][0], "non-unique", "unique")
				cname = ", ".join(map(lambda x: x[4], a))
				d.append("  %s index {%s} on (%s)" % (unique, a[0][1], cname))
		return "\n".join(d)

class IniParser:
	def __init__(self, cfg, key='name'):
		self.key = key
		self.records = {}
		self.ctypeRE = re.compile("\[(jdbc|odbc|default)\]")
		self.entryRE = re.compile("([a-zA-Z]+)[ \t]*=[ \t]*(.*)")
		self.cfg = cfg
		self.parse()

	def parse(self):
		fp = open(self.cfg, "r")
		data = fp.readlines()
		fp.close()
		lines = filter(lambda x: len(x) > 0 and x[0] not in ['#', ';'], map(lambda x: x.strip(), data))
		current = None
		for i in range(len(lines)):
			line = lines[i]
			g = self.ctypeRE.match(line)
			if g:	# a section header
				current = {}
				if not self.records.has_key(g.group(1)):
					self.records[g.group(1)] = []
				self.records[g.group(1)].append(current)
			else:
				g = self.entryRE.match(line)
				if g:
					current[g.group(1)] = g.group(2)

	def __getitem__(self, (ctype, skey)):
		if skey == self.key: return self.records[ctype][0][skey]
		t = filter(lambda x, p=self.key, s=skey: x[p] == s, self.records[ctype])
		if not t or len(t) > 1:
			raise KeyError, "invalid key ('%s', '%s')" % (ctype, skey)
		return t[0]

def random_table_name(prefix, num_chars):
	import random
	d = [prefix, '_']
	i = 0
	while i < num_chars:
		d.append(chr(int(100 * random.random()) % 26 + ord('A')))
		i += 1
	return "".join(d)

class ResultSetRow:
	def __init__(self, rs, row):
		self.row = row
		self.rs = rs
	def __getitem__(self, i):
		if type(i) == type(""):
			i = self.rs.index(i)
		return self.row[i]
	def __getslice__(self, i, j):
		if type(i) == type(""): i = self.rs.index(i)
		if type(j) == type(""): j = self.rs.index(j)
		return self.row[i:j]
	def __len__(self):
		return len(self.row)
	def __repr__(self):
		return str(self.row)

class ResultSet:
	def __init__(self, headers, results=[]):
		self.headers = map(lambda x: x.upper(), headers)
		self.results = results
	def index(self, i):
		return self.headers.index(i.upper())
	def __getitem__(self, i):
		return ResultSetRow(self, self.results[i])
	def __getslice__(self, i, j):
		return map(lambda x, rs=self: ResultSetRow(rs, x), self.results[i:j])
	def __repr__(self):
		return "<%s instance {cols [%d], rows [%d]} at %s>" % (self.__class__, len(self.headers), len(self.results), id(self))