[Sqlalchemy-commits] [1247] sqlalchemy/trunk/lib/sqlalchemy/databases/mssql.py: DOH !
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[Sqlalchemy-commits] [1247] sqlalchemy/trunk/lib/sqlalchemy/databases/mssql.py: DOH !
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From: <co...@sq...> - 2006-04-03 17:13:56
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head><style type="text/css"><!-- #msg dl { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; } #msg dt { float: left; width: 6em; font-weight: bold; } #msg dt:after { content:':';} #msg dl, #msg dt, #msg ul, #msg li { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; } #msg dl a { font-weight: bold} #msg dl a:link { color:#fc3; } #msg dl a:active { color:#ff0; } #msg dl a:visited { color:#cc6; } h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; } #msg pre { overflow: auto; background: #ffc; border: 1px #fc0 solid; padding: 6px; } #msg ul, pre { overflow: auto; } #patch { width: 100%; } #patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;} #patch .propset h4, #patch .binary h4 {margin:0;} #patch pre {padding:0;line-height:1.2em;margin:0;} #patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;} #patch .propset .diff, #patch .binary .diff {padding:10px 0;} #patch span {display:block;padding:0 10px;} #patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;} #patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;} #patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;} #patch .lines, .info {color:#888;background:#fff;} --></style> <title>[1247] sqlalchemy/trunk/lib/sqlalchemy/databases/mssql.py: DOH !</title> </head> <body> <div id="msg"> <dl> <dt>Revision</dt> <dd>1247</dd> <dt>Author</dt> <dd>zzzeek</dd> <dt>Date</dt> <dd>2006-04-03 12:13:42 -0500 (Mon, 03 Apr 2006)</dd> </dl> <h3>Log Message</h3> <pre>DOH !</pre> <h3>Added Paths</h3> <ul> <li><a href="#sqlalchemytrunklibsqlalchemydatabasesmssqlpy">sqlalchemy/trunk/lib/sqlalchemy/databases/mssql.py</a></li> </ul> </div> <div id="patch"> <h3>Diff</h3> <a id="sqlalchemytrunklibsqlalchemydatabasesmssqlpy"></a> <div class="addfile"><h4>Added: sqlalchemy/trunk/lib/sqlalchemy/databases/mssql.py (1246 => 1247)</h4> <pre class="diff"><span> <span class="info">--- sqlalchemy/trunk/lib/sqlalchemy/databases/mssql.py 2006-04-03 05:50:34 UTC (rev 1246) +++ sqlalchemy/trunk/lib/sqlalchemy/databases/mssql.py 2006-04-03 17:13:42 UTC (rev 1247) </span><span class="lines">@@ -0,0 +1,492 @@ </span><ins>+# mssql.py + +""" +notes: + supports both pymssql and adodbapi interfaces + + IDENTITY columns are supported by using SA schema.Sequence() objects. In other words: + Table('test', mss_engine, + Column('id', Integer, Sequence('blah',100,10), primary_key=True), + Column('name', String(20)) + ).create() + + would yield: + CREATE TABLE test ( + id INTEGER NOT NULL IDENTITY(100,10) PRIMARY KEY, + name VARCHAR(20) + ) + note that the start & increment values for sequences are optional and will default to 1,1 + + support for SET IDENTITY_INSERT ON mode (automagic on / off for INSERTs) + + support for auto-fetching of @@IDENTITY on insert + + select.limit implemented as SELECT TOP n + + +Known issues / TODO: + no support for more than one IDENTITY column per table + no support for table reflection of IDENTITY columns with (seed,increment) values other than (1,1) + no support for GUID type columns (yet) + pymssql has problems with transaction control that this module attempts to work around + pymssql has problems with binary and unicode data that this module does NOT work around + adodbapi fails testtypes.py unit test on unicode data too -- issue with the test? + +""" + +import sys, StringIO, string, types, re, datetime + +import sqlalchemy.sql as sql +import sqlalchemy.engine as engine +import sqlalchemy.schema as schema +import sqlalchemy.ansisql as ansisql +import sqlalchemy.types as sqltypes +from sqlalchemy import * + +try: + import adodbapi as dbmodule + # ADODBAPI has a non-standard Connection method + connect = dbmodule.Connection + make_connect_string = lambda keys: \ + [["Provider=SQLOLEDB;Data Source=%s;User Id=%s;Password=%s;Initial Catalog=%s" % ( + keys["host"], keys["user"], keys["password"], keys["database"])], {}] + do_commit = False +except: + try: + import pymssql as dbmodule + connect = dbmodule.connect + # pymmsql doesn't have a Binary method. we use string + dbmodule.Binary = lambda st: str(st) + make_connect_string = lambda keys: \ + [[], keys] + do_commit = True + except: + dbmodule = None + make_connect_string = lambda keys: [[],{}] + +class MSNumeric(sqltypes.Numeric): + def convert_result_value(self, value, engine): + return value + + def convert_bind_param(self, value, engine): + if value is None: + # Not sure that this exception is needed + return value + else: + return str(value) + + def get_col_spec(self): + return "NUMERIC(%(precision)s, %(length)s)" % {'precision': self.precision, 'length' : self.length} + +class MSFloat(sqltypes.Float): + def get_col_spec(self): + return "FLOAT(%(precision)s)" % {'precision': self.precision} + def convert_bind_param(self, value, engine): + """By converting to string, we can use Decimal types round-trip.""" + return str(value) + +class MSInteger(sqltypes.Integer): + def get_col_spec(self): + return "INTEGER" + +class MSSmallInteger(sqltypes.Smallinteger): + def get_col_spec(self): + return "SMALLINT" + +class MSDateTime(sqltypes.DateTime): + def get_col_spec(self): + return "DATETIME" + + def convert_bind_param(self, value, engine): + if hasattr(value, "isoformat"): + return value.isoformat(' ') + else: + return value + + def convert_result_value(self, value, engine): + # adodbapi will return datetimes with empty time values as datetime.date() objects. Promote them back to full datetime.datetime() + if value and not hasattr(value, 'second'): + return datetime.datetime(value.year, value.month, value.day) + return value + +class MSDate(sqltypes.Date): + def get_col_spec(self): + return "SMALLDATETIME" + + def convert_bind_param(self, value, engine): + if value and hasattr(value, "isoformat"): + return value.isoformat() + return value + + def convert_result_value(self, value, engine): + # pymssql will return SMALLDATETIME values as datetime.datetime(), truncate it back to datetime.date() + if value and hasattr(value, 'second'): + return value.date() + return value + +class MSText(sqltypes.TEXT): + def get_col_spec(self): + return "TEXT" +class MSString(sqltypes.String): + def get_col_spec(self): + return "VARCHAR(%(length)s)" % {'length' : self.length} +class MSChar(sqltypes.CHAR): + def get_col_spec(self): + return "CHAR(%(length)s)" % {'length' : self.length} +class MSBinary(sqltypes.Binary): + def get_col_spec(self): + return "IMAGE" +class MSBoolean(sqltypes.Boolean): + def get_col_spec(self): + return "BIT" + +colspecs = { + sqltypes.Integer : MSInteger, + sqltypes.Smallinteger: MSSmallInteger, + sqltypes.Numeric : MSNumeric, + sqltypes.Float : MSFloat, + sqltypes.DateTime : MSDateTime, + sqltypes.Date : MSDate, + sqltypes.String : MSString, + sqltypes.Binary : MSBinary, + sqltypes.Boolean : MSBoolean, + sqltypes.TEXT : MSText, + sqltypes.CHAR: MSChar, +} + +ischema_names = { + 'int' : MSInteger, + 'smallint' : MSSmallInteger, + 'varchar' : MSString, + 'char' : MSChar, + 'text' : MSText, + 'decimal' : MSNumeric, + 'numeric' : MSNumeric, + 'float' : MSFloat, + 'datetime' : MSDateTime, + 'smalldatetime' : MSDate, + 'binary' : MSBinary, + 'bit': MSBoolean, + 'real' : MSFloat, + 'image' : MSBinary +} + +def engine(opts, **params): + return MSSQLEngine(opts, **params) + +def descriptor(): + return {'name':'mssql', + 'description':'MSSQL', + 'arguments':[ + ('user',"Database Username",None), + ('password',"Database Password",None), + ('db',"Database Name",None), + ('host',"Hostname", None), + ]} + +class MSSQLEngine(ansisql.ANSISQLEngine): + def __init__(self, opts, module = None, **params): + if module is None: + self.module = dbmodule + self.opts = opts or {} + ansisql.ANSISQLEngine.__init__(self, **params) + + def connect_args(self): + return make_connect_string(self.opts) + + def type_descriptor(self, typeobj): + return sqltypes.adapt_type(typeobj, colspecs) + + def last_inserted_ids(self): + return self.context.last_inserted_ids + + def supports_sane_rowcount(self): + return True + + def compiler(self, statement, bindparams, **kwargs): + return MSSQLCompiler(statement, bindparams, engine=self, **kwargs) + + def schemagenerator(self, **params): + return MSSQLSchemaGenerator(self, **params) + + def schemadropper(self, **params): + return MSSQLSchemaDropper(self, **params) + + def get_default_schema_name(self): + return "dbo" + + def last_inserted_ids(self): + return self.context.last_inserted_ids + + def do_begin(self, connection): + """implementations might want to put logic here for turning autocommit on/off, etc.""" + if do_commit: + pass + + def _execute(self, c, statement, parameters): + try: + c.execute(statement, parameters) + self.context.rowcount = c.rowcount + c.DBPROP_COMMITPRESERVE = "Y" + except Exception, e: + # del c.parent # Close the Parent Connection, delete it from the pool + raise exceptions.SQLError(statement, parameters, e) + + + def do_rollback(self, connection): + """implementations might want to put logic here for turning autocommit on/off, etc.""" + if do_commit: + try: + # connection.rollback() for pymmsql failed sometimes--the begin tran doesn't show up + # this is a workaround that seems to be handle it. + r = self.raw_connection(connection) + r.query("if @@trancount > 0 rollback tran") + r.fetch_array() + r.query("begin tran") + r.fetch_array() + except: + pass + try: + del connection + except: + raise + + def raw_connection(self, connection): + """Pull the raw pymmsql connection out--sensative to "pool.ConnectionFairy" and pymssql.pymssqlCnx Classes""" + try: + return connection.connection.__dict__['_pymssqlCnx__cnx'] + except: + return connection.connection.adoConn + + def do_commit(self, connection): + """implementations might want to put logic here for turning autocommit on/off, etc. + do_commit is set for pymmsql connections--ADO seems to handle transactions without any issue + """ + # ADO Uses Implicit Transactions. + if do_commit: + # This is very pymssql specific. We use this instead of its commit, because it hangs on failed rollbacks. + # By using the "if" we don't assume an open transaction--much better. + r = self.raw_connection(connection) + r.query("if @@trancount > 0 commit tran") + r.fetch_array() + r.query("begin tran") + r.fetch_array() + else: + pass + #connection.supportsTransactions = 1 + try: + pass + #connection.adoConn.CommitTrans() + except: + pass + #connection.adoConn.execute("begin trans", {}) + #connection.adoConn.BeginTrans() + + def connection(self): + """returns a managed DBAPI connection from this SQLEngine's connection pool.""" + c = self._pool.connect() + c.supportsTransactions = 0 + return c + + def pre_exec(self, proxy, compiled, parameters, **kwargs): + """ MS-SQL has a special mode for inserting non-NULL values into IDENTITY columns. Activate it if needed. """ + if getattr(compiled, "isinsert", False): + self.context.IINSERT = False + self.context.HASIDENT = False + for c in compiled.statement.table.c: + if hasattr(c,'sequence'): + self.context.HASIDENT = True + if parameters.has_key(c.name): + self.context.IINSERT = True + break + if self.context.IINSERT: + proxy("SET IDENTITY_INSERT %s ON" % compiled.statement.table.name) + + def post_exec(self, proxy, compiled, parameters, **kwargs): + """ Turn off the INDENTITY_INSERT mode if it's been activated, and fetch recently inserted IDENTIFY values (works only for one column) """ + if getattr(compiled, "isinsert", False): + if self.context.IINSERT: + proxy("SET IDENTITY_INSERT %s OFF" % compiled.statement.table.name) + self.context.IINSERT = False + elif self.context.HASIDENT: + cursor = proxy("SELECT @@IDENTITY AS lastrowid") + row = cursor.fetchone() + self.context.last_inserted_ids = [row[0]] + self.context.HASIDENT = False + + def dbapi(self): + return self.module + + def reflecttable(self, table): + import sqlalchemy.databases.information_schema as ischema + + # Get base columns + if table.schema is not None: + current_schema = table.schema + else: + current_schema = self.get_default_schema_name() + + columns = ischema.gen_columns.toengine(self) + s = select([columns], + current_schema and sql.and_(columns.c.table_name==table.name, columns.c.table_schema==current_schema) or columns.c.table_name==table.name, + order_by=[columns.c.ordinal_position]) + + c = s.execute() + while True: + row = c.fetchone() + if row is None: + break + + (name, type, nullable, charlen, numericprec, numericscale, default) = ( + row[columns.c.column_name], + row[columns.c.data_type], + row[columns.c.is_nullable] == 'YES', + row[columns.c.character_maximum_length], + row[columns.c.numeric_precision], + row[columns.c.numeric_scale], + row[columns.c.column_default] + ) + + args = [] + for a in (charlen, numericprec, numericscale): + if a is not None: + args.append(a) + coltype = ischema_names[type] + + coltype = coltype(*args) + colargs= [] + if default is not None: + colargs.append(PassiveDefault(sql.text(default))) + + table.append_item(schema.Column(name, coltype, nullable=nullable, *colargs)) + + + # We also run an sp_columns to check for identity columns: + # FIXME: note that this only fetches the existence of an identity column, not it's properties like (seed, increment) + cursor = table.engine.execute("sp_columns " + table.name, {}) + while True: + row = cursor.fetchone() + if row is None: + break + col_name, type_name = row[3], row[5] + if type_name.endswith("identity"): + ic = table.c[col_name] + # setup a psuedo-sequence to represent the identity attribute - we interpret this at table.create() time as the identity attribute + ic.sequence = schema.Sequence(ic.name + '_identity') + + # Add constraints + RR = ischema.gen_ref_constraints.toengine(self) #information_schema.referential_constraints + TC = ischema.gen_constraints.toengine(self) #information_schema.table_constraints + C = ischema.gen_column_constraints.toengine(self).alias('C') #information_schema.constraint_column_usage: the constrained column + R = ischema.gen_column_constraints.toengine(self).alias('R') #information_schema.constraint_column_usage: the referenced column + + fromjoin = TC.join(RR, RR.c.constraint_name == TC.c.constraint_name).join(C, C.c.constraint_name == RR.c.constraint_name) + fromjoin = fromjoin.join(R, R.c.constraint_name == RR.c.unique_constraint_name) + + s = select([TC.c.constraint_type, C.c.table_schema, C.c.table_name, C.c.column_name, + R.c.table_schema, R.c.table_name, R.c.column_name], + and_(RR.c.constraint_schema == current_schema, C.c.table_name == table.name), + from_obj = [fromjoin] + ) + + c = s.execute() + + while True: + row = c.fetchone() + if row is None: + break + (type, constrained_column, referred_schema, referred_table, referred_column) = ( + row[colmap[0]], + row[colmap[3]], + row[colmap[4]], + row[colmap[5]], + row[colmap[6]] + ) + + if type=='PRIMARY KEY': + table.c[constrained_column]._set_primary_key() + elif type=='FOREIGN KEY': + remotetable = Table(referred_table, self, autoload = True, schema=referred_schema) + table.c[constrained_column].append_item(schema.ForeignKey(remotetable.c[referred_column])) + + + +class MSSQLCompiler(ansisql.ANSICompiler): + def __init__(self, *args, **kwargs): + super(MSSQLCompiler, self).__init__(*args, **kwargs) + self.tablealiases = {} + + def visit_select_precolumns(self, select): + """ MS-SQL puts TOP, it's version of LIMIT here """ + s = select.distinct and "DISTINCT " or "" + if (select.limit): + s += "TOP %s " % (select.limit,) + return s + + def limit_clause(self, select): + # Limit in mssql is after the select keyword; MSsql has no support for offset + return "" + + + def visit_table(self, table): + # alias schema-qualified tables + if self.tablealiases.has_key(table): + super(MSSQLCompiler, self).visit_table(table) + elif getattr(table, 'schema', None) is not None: + alias = table.alias() + self.tablealiases[table] = alias + alias.accept_visitor(self) + self.froms[('alias', table)] = self.froms[table] + for c in alias.c: + c.accept_visitor(self) + self.tablealiases[alias] = self.froms[table] + self.froms[table] = self.froms[alias] + + def visit_alias(self, alias): + # translate for schema-qualified table aliases + if self.froms.has_key(('alias', alias.original)): + self.froms[alias] = self.froms[('alias', alias.original)] + " AS " + alias.name + self.strings[alias] = "" + else: + super(MSSQLCompiler, self).visit_alias(alias) + + def visit_column(self, column): + # translate for schema-qualified table aliases + super(MSSQLCompiler, self).visit_column(column) + if column.table is not None and self.tablealiases.has_key(column.table): + self.strings[column] = \ + self.strings[self.tablealiases[column.table]._get_col_by_original(column.original)] + + +class MSSQLSchemaGenerator(ansisql.ANSISchemaGenerator): + def get_column_specification(self, column, override_pk=False, first_pk=False): + colspec = column.name + " " + column.type.get_col_spec() + + # install a IDENTITY Sequence if we have an implicit IDENTITY column + if column.primary_key and isinstance(column.type, types.Integer): + if column.default is None or (isinstance(column.default, schema.Sequence) and column.default.optional): + column.sequence = schema.Sequence(column.name + '_seq') + + if not column.nullable: + colspec += " NOT NULL" + + if hasattr(column, 'sequence'): + colspec += " IDENTITY(%s,%s)" % (column.sequence.start or 1, column.sequence.increment or 1) + else: + default = self.get_column_default_string(column) + if default is not None: + colspec += " DEFAULT " + default + + if column.primary_key: + if not override_pk: + colspec += " PRIMARY KEY" + if column.foreign_key: + colspec += " REFERENCES %s(%s)" % (column.foreign_key.column.table.fullname, column.foreign_key.column.name) + + return colspec + + +class MSSQLSchemaDropper(ansisql.ANSISchemaDropper): + def visit_index(self, index): + self.append("\nDROP INDEX " + index.table.name + "." + index.name) + self.execute() </ins></span></pre> </div> </div> </body> </html> |
