Ticket #2563: introspection.diff

File introspection.diff, 7.4 KB (added by sdelatorre+django@…, 9 years ago)

The SVN diff of the patch.

  • django/db/backends/ado_mssql/introspection.py

     
    1 def get_table_list(cursor):
    2     raise NotImplementedError
     1# Tested against MSDE and SQL Server 2000 using adodbapi 2.0.1
     2# Python 2.4.2 and 2.4.3 were used during testing.
     3from django.db.backends.ado_mssql.base import Cursor
     4
     5def get_table_list(cursor):
     6    "Returns a list of table names in the current database."
     7    print "# Note: Any fields that are named 'id', are of type 'AutoField', and"
     8    print "# and are Primary Keys will NOT appear in the model output below."
     9    print "# By default Django assumes that the each model's Primary Key is an "
     10    print "# AutoField with a name of 'id', so there is no need to add it to the"
     11    print "# model description."
     12    print
     13    cursor.execute("SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE'")
     14    return [row[2] for row in cursor.fetchall()]
     15
     16def _is_auto_field(cursor, table_name, column_name):
     17    cursor.execute("SELECT COLUMNPROPERTY( OBJECT_ID('%s'),'%s','IsIdentity')" % (table_name, column_name))
     18    return cursor.fetchall()[0][0]
    319
    4 def get_table_description(cursor, table_name):
    5     raise NotImplementedError
     20def get_table_description(cursor, table_name, identity_check=True):
     21    """Returns a description of the table, with the DB-API cursor.description interface.
     22
     23    The 'auto_check' parameter has been added to the function argspec.
     24    If set to True, the function will check each of the table's fields for the
     25    IDENTITY property (the IDENTITY property is the MSSQL equivalent to an AutoField).
     26
     27    When a field is found with an IDENTITY property, it is given a custom field number
     28    of -777, which maps to the 'AutoField' value in the DATA_TYPES_REVERSE dict.
     29    """   
     30    cursor.execute("SELECT TOP 1 * FROM %s" % table_name)
     31    cursor.nextset()
     32    items = []
     33    if identity_check:
     34        for data in cursor.description:
     35            if _is_auto_field(cursor, table_name, data[0]):
     36                data = list(data)
     37                data[1] = -777
     38            items.append(list(data))
     39    else:
     40        items = cursor.description
     41    return items
     42
     43def _name_to_index(cursor, table_name):
     44    """
     45    Returns a dictionary of {field_name: field_index} for the given table.
     46    Indexes are 0-based.
     47    """
     48    return dict([(d[0], i) for i, d in enumerate(get_table_description(cursor, table_name, identity_check=False))])
    649
    7 def get_relations(cursor, table_name):
    8     raise NotImplementedError
    9 
    10 def get_indexes(cursor, table_name):
    11     raise NotImplementedError
    12 
    13 DATA_TYPES_REVERSE = {}
     50def get_relations(cursor, table_name):
     51    """
     52    Returns a dictionary of {field_index: (field_index_other_table, other_table)}
     53    representing all relationships to the given table. Indexes are 0-based.   
     54    """
     55    table_index = _name_to_index(cursor, table_name)
     56    sql = """SELECT e.COLUMN_NAME AS column_name,
     57                    c.TABLE_NAME AS referenced_table_name,
     58                    d.COLUMN_NAME AS referenced_column_name
     59                    FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS a
     60                        INNER JOIN INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS b
     61                              ON a.CONSTRAINT_NAME = b.CONSTRAINT_NAME
     62                        INNER JOIN INFORMATION_SCHEMA.CONSTRAINT_TABLE_USAGE AS c
     63                              ON b.UNIQUE_CONSTRAINT_NAME = c.CONSTRAINT_NAME
     64                        INNER JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE AS d
     65                              ON c.CONSTRAINT_NAME = d.CONSTRAINT_NAME
     66                        INNER JOIN INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE AS e
     67                              ON a.CONSTRAINT_NAME = e.CONSTRAINT_NAME
     68                    WHERE a.TABLE_NAME = ? AND
     69                          a.CONSTRAINT_TYPE = 'FOREIGN KEY'"""
     70    cursor = Cursor(cursor.db.connection)
     71    cursor.execute(sql, (table_name,))
     72    return dict([(table_index[item[0]], (_name_to_index(cursor, item[1])[item[2]], item[1]))
     73                  for item in cursor.fetchall()])
     74   
     75def get_indexes(cursor, table_name):
     76    """
     77    Returns a dictionary of fieldname -> infodict for the given table,
     78    where each infodict is in the format:
     79        {'primary_key': boolean representing whether it's the primary key,
     80         'unique': boolean representing whether it's a unique index}
     81    """
     82    sql = """SELECT b.COLUMN_NAME, a.CONSTRAINT_TYPE
     83               FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS AS a INNER JOIN
     84                    INFORMATION_SCHEMA.CONSTRAINT_COLUMN_USAGE AS b
     85                    ON a.CONSTRAINT_NAME = b.CONSTRAINT_NAME AND
     86                       a.TABLE_NAME = b.TABLE_NAME
     87               WHERE a.TABLE_NAME = ? AND
     88                     (CONSTRAINT_TYPE = 'PRIMARY KEY' OR
     89                      CONSTRAINT_TYPE = 'UNIQUE')"""
     90    field_names = [item[0] for item in get_table_description(cursor, table_name, identity_check=False)]
     91    cursor = Cursor(cursor.db.connection)
     92    cursor.execute(sql, (table_name,))
     93    indexes = {}
     94    results = {}
     95    data = cursor.fetchall()
     96    if data:
     97        results.update(data)
     98    for field in field_names:
     99        val = results.get(field, None)
     100        indexes[field] = dict(primary_key=(val=='PRIMARY KEY'), unique=(val=='UNIQUE'))
     101    return indexes
     102
     103# A reference for the values below:
     104# http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ado270/htm/mdcstdatatypeenum.asp
     105DATA_TYPES_REVERSE = {
     106# 8192 : Array ,
     107# 128 : Binary ,
     108# 9 : IDispatch ,
     109# 12 : Variant ,
     110# 13 : IUnknown ,
     111# 21  : UnsignedBigInt,
     112# 132 : UserDefined ,
     113# 0   : Empty ,
     114# 136 : Chapter ,
     115# 138 : PropVariant ,
     116# 204 : VarBinary ,
     117# 205 : LongVarBinary ,
     118-777: 'AutoField',                  # Custom number used to identify AutoFields
     1192   : 'SmallIntegerField',          # SmallInt
     1203   : 'IntegerField',               # Integer
     1214   : 'FloatField',                 # Single
     1225   : 'FloatField',                 # Decimal
     1236   : 'FloatField',                 # Currency
     1247   : 'DateField',                  # Date
     1258   : 'CharField',                  # BSTR
     12610  : 'IntegerField',               # Error
     12711  : 'BooleanField',               # Boolean
     12814  : 'FloatField',                 # Decimal
     12916  : 'SmallIntegerField',          # TinyInt
     13017  : 'PositiveSmallIntegerField',  # UnsignedTinyInt
     13118  : 'PositiveSmallIntegerField',  # UnsignedSmallInt
     13219  : 'PositiveIntegerField',       # UnsignedInt
     13320  : 'IntegerField',               # BigInt
     13464  : 'DateTimeField',              # FileTime
     13572  : 'CharField',                  # GUID
     136129 : 'CharField',                  # Char
     137130 : 'CharField',                  # WChar
     138131 : 'FloatField',                 # Numeric
     139133 : 'DateField',                  # DBDate
     140134 : 'TimeField',                  # DBTime
     141135 : 'DateTimeField',              # DBTimeStamp
     142139 : 'FloatField',                 # VarNumeric
     143200 : 'CharField',                  # VarChar
     144201 : 'TextField',                  # LongVarChar
     145202 : 'CharField',                  # VarWChar
     146203 : 'TextField',                  # LongVarWChar
     147}
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