Mercurial > p > roundup > code
comparison roundup/backends/rdbms_common.py @ 2073:261c2e6ceb1e
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| author | Richard Jones <richard@users.sourceforge.net> |
|---|---|
| date | Fri, 05 Mar 2004 00:08:09 +0000 |
| parents | fc52d57c6c3e |
| children | b1704ba7be41 |
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| 2069:d8c7fd205cd8 | 2073:261c2e6ceb1e |
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| 1 # $Id: rdbms_common.py,v 1.75 2004-02-11 23:55:09 richard Exp $ | 1 # $Id: rdbms_common.py,v 1.76 2004-03-05 00:08:09 richard Exp $ |
| 2 ''' Relational database (SQL) backend common code. | 2 ''' Relational database (SQL) backend common code. |
| 3 | 3 |
| 4 Basics: | 4 Basics: |
| 5 | 5 |
| 6 - map roundup classes to relational tables | 6 - map roundup classes to relational tables |
| 17 Database-specific changes may generally be pushed out to the overridable | 17 Database-specific changes may generally be pushed out to the overridable |
| 18 sql_* methods, since everything else should be fairly generic. There's | 18 sql_* methods, since everything else should be fairly generic. There's |
| 19 probably a bit of work to be done if a database is used that actually | 19 probably a bit of work to be done if a database is used that actually |
| 20 honors column typing, since the initial databases don't (sqlite stores | 20 honors column typing, since the initial databases don't (sqlite stores |
| 21 everything as a string.) | 21 everything as a string.) |
| 22 | |
| 23 The schema of the hyperdb being mapped to the database is stored in the | |
| 24 database itself as a repr()'ed dictionary of information about each Class | |
| 25 that maps to a table. If that information differs from the hyperdb schema, | |
| 26 then we update it. We also store in the schema dict a __version__ which | |
| 27 allows us to upgrade the database schema when necessary. See upgrade_db(). | |
| 22 ''' | 28 ''' |
| 23 __docformat__ = 'restructuredtext' | 29 __docformat__ = 'restructuredtext' |
| 24 | 30 |
| 25 # standard python modules | 31 # standard python modules |
| 26 import sys, os, time, re, errno, weakref, copy | 32 import sys, os, time, re, errno, weakref, copy |
| 75 def clearCache(self): | 81 def clearCache(self): |
| 76 self.cache = {} | 82 self.cache = {} |
| 77 self.cache_lru = [] | 83 self.cache_lru = [] |
| 78 | 84 |
| 79 def sql_open_connection(self): | 85 def sql_open_connection(self): |
| 80 ''' Open a connection to the database, creating it if necessary | 86 ''' Open a connection to the database, creating it if necessary. |
| 87 | |
| 88 Must call self.load_dbschema() | |
| 81 ''' | 89 ''' |
| 82 raise NotImplemented | 90 raise NotImplemented |
| 83 | 91 |
| 84 def sql(self, sql, args=None): | 92 def sql(self, sql, args=None): |
| 85 ''' Execute the sql with the optional args. | 93 ''' Execute the sql with the optional args. |
| 104 def sql_stringquote(self, value): | 112 def sql_stringquote(self, value): |
| 105 ''' Quote the string so it's safe to put in the 'sql quotes' | 113 ''' Quote the string so it's safe to put in the 'sql quotes' |
| 106 ''' | 114 ''' |
| 107 return re.sub("'", "''", str(value)) | 115 return re.sub("'", "''", str(value)) |
| 108 | 116 |
| 117 def load_dbschema(self): | |
| 118 ''' Load the schema definition that the database currently implements | |
| 119 ''' | |
| 120 self.cursor.execute('select schema from schema') | |
| 121 self.database_schema = eval(self.cursor.fetchone()[0]) | |
| 122 | |
| 109 def save_dbschema(self, schema): | 123 def save_dbschema(self, schema): |
| 110 ''' Save the schema definition that the database currently implements | 124 ''' Save the schema definition that the database currently implements |
| 111 ''' | 125 ''' |
| 112 s = repr(self.database_schema) | 126 s = repr(self.database_schema) |
| 113 self.sql('insert into schema values (%s)', (s,)) | 127 self.sql('insert into schema values (%s)', (s,)) |
| 114 | 128 |
| 115 def load_dbschema(self): | |
| 116 ''' Load the schema definition that the database currently implements | |
| 117 ''' | |
| 118 self.cursor.execute('select schema from schema') | |
| 119 return eval(self.cursor.fetchone()[0]) | |
| 120 | |
| 121 def post_init(self): | 129 def post_init(self): |
| 122 ''' Called once the schema initialisation has finished. | 130 ''' Called once the schema initialisation has finished. |
| 123 | 131 |
| 124 We should now confirm that the schema defined by our "classes" | 132 We should now confirm that the schema defined by our "classes" |
| 125 attribute actually matches the schema in the database. | 133 attribute actually matches the schema in the database. |
| 126 ''' | 134 ''' |
| 135 self.upgrade_db() | |
| 136 | |
| 127 # now detect changes in the schema | 137 # now detect changes in the schema |
| 128 save = 0 | 138 save = 0 |
| 129 for classname, spec in self.classes.items(): | 139 for classname, spec in self.classes.items(): |
| 130 if self.database_schema.has_key(classname): | 140 if self.database_schema.has_key(classname): |
| 131 dbspec = self.database_schema[classname] | 141 dbspec = self.database_schema[classname] |
| 152 if self.indexer.should_reindex(): | 162 if self.indexer.should_reindex(): |
| 153 self.reindex() | 163 self.reindex() |
| 154 | 164 |
| 155 # commit | 165 # commit |
| 156 self.conn.commit() | 166 self.conn.commit() |
| 167 | |
| 168 # update this number when we need to make changes to the SQL structure | |
| 169 # of the backen database | |
| 170 current_db_version = 2 | |
| 171 def upgrade_db(self): | |
| 172 ''' Update the SQL database to reflect changes in the backend code. | |
| 173 ''' | |
| 174 version = self.database_schema.get('__version', 1) | |
| 175 if version == 1: | |
| 176 # version 1 doesn't have the OTK, session and indexing in the | |
| 177 # database | |
| 178 self.create_version_2_tables() | |
| 179 | |
| 180 self.database_schema['__version'] = self.current_db_version | |
| 181 | |
| 157 | 182 |
| 158 def refresh_database(self): | 183 def refresh_database(self): |
| 159 self.post_init() | 184 self.post_init() |
| 160 | 185 |
| 161 def reindex(self): | 186 def reindex(self): |