def main():
connectionString = 'driver=' + DRIVER + ';server=' + SERVER_ADDRESS + ';database=' + DATABASE_NAME + ';uid=' + UID + ';pwd=' + PASSWORD
cnxn = pyodbc.connect(connectionString)
cursor = cnxn.cursor()
mongoClient = MongoClient(MONGO_DATABASE_ADDRESS)
db = mongoClient[DATABASE_NAME]
columnData = getColumnData(cursor)
tableNames = set(row.TABLE_NAME for row in columnData)
pKeys = getPrimaryKeys(cursor)
fKeys = getForeignKeys(cursor)
graph = buildDependencyGraph(tableNames, columnData, pKeys, fKeys)
if len(db.collection_names()) < 1:
print "Exporting data..."
tablesJSON = {}
for table in graph:
tableDataExtractor = TableDataExtractor()
result = tableDataExtractor.extractData(cursor, table)
tablesJSON[table.tableName] = result
for tableName in tablesJSON:
for entry in tablesJSON[tableName]:
print "Inserting table " + tableName + " into Mongo..."
db[tableName].insert(entry)
print "Done."
else:
print "Checking for changes..."
delta(graph, cursor, db)
print "Operation Complete"
def delta(graph, cursor, mongoDB):
extractor = TableDataExtractor()
for table in graph:
sqlKeys = extractor.getPrimaryKeyValues(cursor, table)
#print "SQL Keys: " + str(sqlKeys)
mongoKeys = [str(entry[table.primaryKey[0]]) for entry in mongoDB[table.tableName].find()]
#print "Mongo Keys: " + str(mongoKeys)
sqlSet = set(sqlKeys)
mongoSet = set(mongoKeys)
newKeys = sqlSet.difference(mongoSet)
insertNewKeys(mongoDB, cursor, extractor, newKeys, table, table.primaryKey[0])
deletedKeys = mongoSet.difference(sqlSet)
deleteRemovedKeys(mongoDB, deletedKeys, table.tableName, table.primaryKey[0])