A python implementation of structure query language
MypseudoSQL.Table(columns)
from MypseudoSQL import Table
table = Table(["col_0", "col_1", ...])
table.insert([val_0, val_1, ...])
columns: specifying the names of the table's columns
list
rows: a dataset as a row which values corresponding to table's columns
list
| MypseudoSQL | SQL |
| insert(row_values) | INSERT INTO |
| update(updates, predicate) | UPDATE |
| delete() | DELETE |
| select() | SELECT |
| limit(lim) | LIMIT |
| where() | WHERE |
| group_by(group_by_columns, aggregates) | GROUP BY |
| order_by(order) | ORDER BY |
| join(other_table) | JOIN |
insert(row_values)
dict from column names to values
parameter:
row_values: dict of list
return:
void
update(updates, predicate)
updates will be a dict whose keys are the columns to update and whose values are the new values for those fields.
predicate is a predicate that returns True for rows that should be updated, False otherwise
parameter:
updates: dict
return:
void
delete(predicate=function)
to delete rows from a table
parameter:
predicate: a predicate function, default=lambda row: True
return:
void
select(keep_columns=None, additional_columns=None)
keep_columns specifies the name of the columns you want to keep in the result.
additional_columns is a dictionary whose keys are new column names and whose values are functions specifying how to compute the values of the new columns.
parameter:
keep_columns: list, default=None
additional_columns: dict, {column: predicate function}, default=None
return: Table
limit(lim)
to select a limited number of records
parameter:
lim: int
return:
Table
where(predicate=function)
defines the condition to be met for the rows to be returned
parameter:
predicate: a predicate function, default=lambda row: True
return:
Table
group_by(group_by_columns, aggregates, having=None)
group together rows with identical values in specified columns and produces aggregate values
parameter:
group_by_columns: list
aggregates: dict, {col: predicate function}
having: a predicate function, default=None
return:
Table
order_by(order)
sorts data returned by a predicate function
parameter:
order: a predicate function
return:
Table
join(other_table, left_join=False)
join two tables
parameter:
other_table: Table
left_join: boolean, default=False
return:
Table