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wip juntar

This commit is contained in:
José Henrique Ivanchechen 2023-11-23 22:38:46 -03:00
parent 0f64ed400c
commit 6a3e11cc79
2 changed files with 65 additions and 11 deletions
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2
main.py
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@ -32,5 +32,7 @@ def main():
sql = SQL(tables, query) sql = SQL(tables, query)
sql.execute() sql.execute()
print()
if __name__ == "__main__": if __name__ == "__main__":
main() main()

74
sql.py
View File

@ -17,25 +17,77 @@ class SQL:
else: else:
pass pass
# SELECIONAR * DE tabela ONDE coluna = valor JUNTAR tabela2 coluna # SELECIONAR * DE tabela JUNTAR tabela2 coluna ONDE coluna = valor
def select(self, query_parts: list) -> None: def select(self, query_parts: list) -> None:
where_filter = None where_filter = None
join_stmt = None join_stmt = None
if "ONDE" in query_parts:
index = query_parts.index("ONDE")
where_filter_column = query_parts[index + 1]
where_filter_operator = query_parts[index + 2]
where_filter_value = query_parts[index + 3]
where_filter = [where_filter_column, where_filter_operator, where_filter_value]
if "JUNTAR" in query_parts: if "JUNTAR" in query_parts:
index = query_parts.index("JUNTAR") index = query_parts.index("JUNTAR")
join_table = query_parts[index + 1] join_table = query_parts[index + 1]
join_column = query_parts[index + 2] join_column = query_parts[index + 2]
join_stmt = [self.tables[join_table], join_column] join_stmt = [self.tables[join_table], join_column]
if "ONDE" in query_parts:
index = query_parts.index("ONDE")
where_filter_column = query_parts[index + 1]
where_filter_value = query_parts[index + 2]
where_filter = [where_filter_column, where_filter_value]
# parse TABLE
table = self.tables[query_parts[3]] table = self.tables[query_parts[3]]
table.print_columns(table.columns,
where_filter=where_filter, # parse SELECT COLUMNS
join_stmt=join_stmt) column_list = query_parts[1].split(",")
for i in range(len(column_list)):
column_list[i] = column_list[i].strip()
if column_list[0] == '*':
column_list = table.columns
# print the columns
print(', '.join(column_list))
print('-' * 20)
# print the rows
tables_columns = table.columns
tables_rows = table.rows
if join_stmt is not None:
join_table = join_stmt[0]
join_column = join_stmt[1]
for row in table.rows:
column_index = table.columns.index(join_column)
row_value = row[column_index]
for join_row in join_table.rows:
join_column_index = join_table.columns.index(join_column)
join_row_value = join_row[join_column_index]
if row_value == join_row_value:
tables_rows.append(row + join_row)
tables_columns = table.columns + join_table.columns
for row in tables_rows:
if where_filter is not None:
column_index = tables_columns.index(where_filter[0])
row_value = row[column_index]
if where_filter[1] == '=':
if row_value != where_filter[2]:
continue
elif where_filter[1] == '>':
if row_value <= where_filter[2]:
continue
elif where_filter[1] == '<':
if row_value >= where_filter[2]:
continue
row_values = []
for column in column_list:
column_index = tables_columns.index(column)
row_values.append(row[column_index])
print(', '.join(row_values))