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1 from django.db.backends.postgresql.base import DatabaseOperations |
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2 |
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3 quote_name = DatabaseOperations().quote_name |
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4 |
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5 def get_table_list(cursor): |
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6 "Returns a list of table names in the current database." |
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7 cursor.execute(""" |
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8 SELECT c.relname |
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9 FROM pg_catalog.pg_class c |
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10 LEFT JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace |
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11 WHERE c.relkind IN ('r', 'v', '') |
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12 AND n.nspname NOT IN ('pg_catalog', 'pg_toast') |
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13 AND pg_catalog.pg_table_is_visible(c.oid)""") |
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14 return [row[0] for row in cursor.fetchall()] |
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15 |
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16 def get_table_description(cursor, table_name): |
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17 "Returns a description of the table, with the DB-API cursor.description interface." |
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18 cursor.execute("SELECT * FROM %s LIMIT 1" % quote_name(table_name)) |
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19 return cursor.description |
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20 |
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21 def get_relations(cursor, table_name): |
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22 """ |
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23 Returns a dictionary of {field_index: (field_index_other_table, other_table)} |
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24 representing all relationships to the given table. Indexes are 0-based. |
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25 """ |
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26 cursor.execute(""" |
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27 SELECT con.conkey, con.confkey, c2.relname |
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28 FROM pg_constraint con, pg_class c1, pg_class c2 |
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29 WHERE c1.oid = con.conrelid |
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30 AND c2.oid = con.confrelid |
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31 AND c1.relname = %s |
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32 AND con.contype = 'f'""", [table_name]) |
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33 relations = {} |
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34 for row in cursor.fetchall(): |
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35 try: |
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36 # row[0] and row[1] are like "{2}", so strip the curly braces. |
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37 relations[int(row[0][1:-1]) - 1] = (int(row[1][1:-1]) - 1, row[2]) |
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38 except ValueError: |
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39 continue |
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40 return relations |
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41 |
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42 def get_indexes(cursor, table_name): |
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43 """ |
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44 Returns a dictionary of fieldname -> infodict for the given table, |
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45 where each infodict is in the format: |
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46 {'primary_key': boolean representing whether it's the primary key, |
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47 'unique': boolean representing whether it's a unique index} |
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48 """ |
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49 # This query retrieves each index on the given table, including the |
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50 # first associated field name |
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51 cursor.execute(""" |
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52 SELECT attr.attname, idx.indkey, idx.indisunique, idx.indisprimary |
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53 FROM pg_catalog.pg_class c, pg_catalog.pg_class c2, |
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54 pg_catalog.pg_index idx, pg_catalog.pg_attribute attr |
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55 WHERE c.oid = idx.indrelid |
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56 AND idx.indexrelid = c2.oid |
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57 AND attr.attrelid = c.oid |
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58 AND attr.attnum = idx.indkey[0] |
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59 AND c.relname = %s""", [table_name]) |
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60 indexes = {} |
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61 for row in cursor.fetchall(): |
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62 # row[1] (idx.indkey) is stored in the DB as an array. It comes out as |
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63 # a string of space-separated integers. This designates the field |
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64 # indexes (1-based) of the fields that have indexes on the table. |
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65 # Here, we skip any indexes across multiple fields. |
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66 if ' ' in row[1]: |
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67 continue |
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68 indexes[row[0]] = {'primary_key': row[3], 'unique': row[2]} |
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69 return indexes |
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70 |
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71 # Maps type codes to Django Field types. |
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72 DATA_TYPES_REVERSE = { |
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73 16: 'BooleanField', |
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74 21: 'SmallIntegerField', |
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75 23: 'IntegerField', |
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76 25: 'TextField', |
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77 701: 'FloatField', |
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78 869: 'IPAddressField', |
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79 1043: 'CharField', |
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80 1082: 'DateField', |
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81 1083: 'TimeField', |
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82 1114: 'DateTimeField', |
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83 1184: 'DateTimeField', |
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84 1266: 'TimeField', |
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85 1700: 'DecimalField', |
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86 } |