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Ticket #2563: introspection.diff

File introspection.diff, 7.4 kB (added by sdelatorre+django@gmail.com, 2 years ago)

The SVN diff of the patch.

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

    old new  
    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}