def drop_table(tname):
catalog.init_catalog()
catalog.exist_table(tname, False)
index.delete_table(tname)
catalog.delete_table(tname)
record.delete_table(tname)
catalog.finalize()
def delete_tuple(tname, condition):
catalog.init_catalog()
catalog.exist_table(tname, False)
clause = extract_condition(condition)
length = catalog.get_length(tname)
index_name = catalog.get_column_with_index(tname)
where = record.delete_record(tname, clause, length)
index.delete_entries(where, tname, index_name)
catalog.finalize()
def drop_table(tname):
'''record.init()
catalog.init_catalog()
index.init_index()'''
catalog.exist_table(tname, False)
index.delete_table(tname)
catalog.delete_table(tname)
record.delete_table(tname)
'''index.finalize_index()
def select(table, condition):
catalog.init_catalog()
catalog.exist_table(table, False)
clause = extract_condition(condition)
attr_list = catalog.get_column_name(table)
length = catalog.get_length(table)
index_name = catalog.get_column_with_index(table)
where = index.select_from_table(table, clause, index_name)
list_res = record.select_record(table, attr_list, clause, where, length)
catalog.finalize()
return list_res
def insert(tname, values):
catalog.init_catalog()
catalog.exist_table(tname, False)
catalog.check_type(tname, values)
index_name = catalog.get_column_with_index(tname)
idx = catalog.get_index_of_attribute(tname, index_name)
key = []
for dxtemp in idx:
key.append(values[dxtemp])
index.insert_entry(tname, index_name, key, values)
record.insert(tname, values)
catalog.finalize()
def create_table(name, attribute, PK):
catalog.init_catalog()
catalog.exist_table(name, True)
pidx = [x[0] for x in attribute].index(PK)
if len(attribute[pidx]) != 5 or attribute[pidx][-1] != 1:
raise Exception('Primary key is not a unique attribute!')
catalog.create_table(name, attribute, PK)
record.create_table(name)
index.create_table(name, PK)
for x in attribute:
if PK not in x and len(x) == 5 and x[-1] == 1:
index.create_index(name, 'Uni_' + x[0], x[0])
catalog.finalize()
def select(table, condition):
'''record.init()
catalog.init_catalog()
index.init_index()'''
catalog.exist_table(table, False)
clauses = []
if len(condition) == 1 and condition[0] == '*':
record.select_record(table, catalog.get_column_name(table), clauses,
None, catalog.get_length(table))
else:
condition = add_space(condition)
cnt = 0
tran = condition.split()
#print(tran)
while (1):
if cnt + 3 > len(tran):
raise Exception('The query condition is illegal')
if tran[cnt + 1] not in ['<', '>', '=', '<>', '>=', '<=']:
raise Exception('The operator ' + tran[cnt + 1] +
' in query is illegal')
if tran[cnt + 1] == '<>':
tran[cnt + 1] = '!='
if tran[cnt + 1] == '=':
tran[cnt + 1] = '=='
clauses.append([
tran[cnt], tran[cnt + 1], tran[cnt + 2],
catalog.get_type_of_attribute(table, tran[cnt]),
catalog.get_index_of_attribute(table, tran[cnt])
])
if cnt + 3 == len(tran):
indexname = catalog.get_column_with_index(table)
index_clause = None
for clause in clauses:
if clause[0] in indexname:
index_clause = clause
break
res = None
if index_clause != None:
clauses.remove(index_clause)
indexname = catalog.get_index_name(table, index_clause[0])
res = index.select_from_table(table, index_clause,
indexname[0])
record.select_record(table, catalog.get_column_name(table),
clauses, res, catalog.get_length(table))
break
if tran[cnt + 3] != 'and':
raise Exception('and expected but ' + tran[cnt + 3] +
' found.')
cnt += 4
'''index.finalize_index()
def delete_tuple(tname, condition):
'''record.init()
catalog.init_catalog()
index.init_index()'''
catalog.exist_table(tname, False)
clauses = []
if len(condition) == 1 and condition[0] == '*':
record.delete_record(tname, clauses, catalog.get_length(tname))
for index_name in catalog.get_index_list(tname):
index.delete_table_index(tname, index_name)
else:
condition = add_space(condition)
cnt = 0
tran = condition.split()
# print(tran)
while (1):
if cnt + 3 > len(tran):
raise Exception('The query condition is illegal')
if tran[cnt + 1] not in ['<', '>', '=', '<>', '>=', '<=']:
raise Exception('The operator ' + tran[cnt + 1] +
' in query is illegal')
if tran[cnt + 1] == '<>':
tran[cnt + 1] = '!='
if tran[cnt + 1] == '=':
tran[cnt + 1] = '=='
clauses.append([
tran[cnt], tran[cnt + 1], tran[cnt + 2],
catalog.get_type_of_attribute(tname, tran[cnt]),
catalog.get_index_of_attribute(tname, tran[cnt])
])
if cnt + 3 == len(tran):
indexname = catalog.get_column_with_index(tname)
res = record.delete_record(tname, clauses,
catalog.get_length(tname))
for cnt, i in enumerate(catalog.get_type_list(tname)):
if i != 'char':
for j in res:
j[cnt] = eval(j[cnt])
for attribute in catalog.get_column_with_index(tname):
attr_id = catalog.get_index_of_attribute(tname, attribute)
for indexname in catalog.get_index_name_by_seq(
tname, attr_id):
index.delete_entries([x[attr_id] for x in res], tname,
indexname)
break
if tran[cnt + 3] != 'and':
raise Exception('and expected but ' + tran[cnt + 3] +
' found.')
cnt += 4
'''index.finalize_index()
def create_table(name, attribute, PK):
'''record.init()
catalog.init_catalog()
index.init_index()'''
catalog.exist_table(name, True)
pidx = [x[0] for x in attribute].index(PK)
if len(attribute[pidx]) != 5 or attribute[pidx][-1] != 1:
raise Exception('Primary key is not a unique attribute!')
catalog.create_table(name, attribute, PK)
record.create_table(name)
for x in attribute:
if len(x) == 5 and x[-1] == 1:
#print(name,x[0])
index.create_table(name, x[0])
catalog.create_index(name, x[0], x[0])
'''index.finalize_index()
def insert(tname, values):
'''record.init()
catalog.init_catalog()
index.init_index()'''
catalog.exist_table(tname, False)
values = catalog.check_type(tname, values)
where = record.insert(tname, values) - catalog.get_length(tname)
for idx, key in enumerate(values):
if catalog.get_index_name_by_seq(tname, idx) != []:
for indexname in catalog.get_index_name_by_seq(tname, idx):
try:
index.insert_entry(tname, indexname, key, where)
except Exception as err:
temp_list = catalog.get_index_name_by_seq(tname, idx)
for index_del in temp_list[:temp_list.index(indexname)]:
index.delete_entries([err], tname, index_del)
record.truncate(tname, where)
raise Exception('Insertion fails. Data with key: ' +
str(key) + ' already exists.')
'''index.finalize_index()