def alterDropColumn(database: str, table: str, columnNumber: int) -> int:
try:
if not database.isidentifier() \
or not table.isidentifier() \
or not isinstance(columnNumber, int):
raise Exception()
baseDatos = __getDatabase(database)
if baseDatos is False:
return 2
tabla = __getTable(database, table)
if tabla is False:
return 3
modo = tabla["mode"]
res = 1
if modo == "avl":
res = avl.alterDropColumn(database, table, columnNumber)
elif modo == "b":
res = b.alterDropColumn(database, table, columnNumber)
elif modo == "bplus":
res = bplus.alterDropColumn(database, table, columnNumber)
elif modo == "hash":
res = ha.alterDropColumn(database, table, columnNumber)
elif modo == "isam":
res = isam.alterDropColumn(database, table, columnNumber)
elif modo == "json":
res = j.alterDropColumn(database, table, columnNumber)
elif modo == "dict":
res = d.alterDropColumn(database, table, columnNumber)
if res == 0:
# Pedir la lista de diccionarios de base de datos
listaDB = __rollback("data")
for db in listaDB:
if db["nameDb"] == database:
for tb in db["tables"]:
if tb["nameTb"] == table:
columnasNew = tb["columns"] - 1
tb["columns"] = columnasNew
break
# Se guarda la lista de base de datos ya actualizada en el archivo data
__commit(listaDB, "data")
return res
except:
return 1
def alterDropColumn(database, table, columnNumber):
try:
dictionary = load('metadata')
if dictionary.get(database) is None:
return 2 # database doesn't exist
mode = dictionary.get(database)[0]
j = checkMode(mode)
value_return = j.alterDropColumn(database, table, columnNumber)
if value_return == 0:
dict_tables = dictionary.get(database)[2]
number_columns = dict_tables.get(table)[0]
dict_tables.get(table)[0] = number_columns-1 # Updating number of columns
save(dictionary, 'metadata')
return value_return
except:
return 1
def alterAddColumn(database, table, default):
try:
database = str(database)
table = str(table)
dictionary = load('metadata')
value_base = dictionary.get(database)
if not value_base:
return 2
mode = dictionary.get(database)[0]
j = checkMode(mode)
value_return = j.alterDropColumn(database, table, default)
if value_return == 0:
dict_tables = dictionary.get(database)[2]
number_columns = dict_tables.get(table)[0]
dict_tables.get(table)[0] = number_columns + 1
save(dictionary, 'metadata')
return value_return
except:
return 1
