sqliteio 0.2.0

Open & Close

Everything starts with open() and ends with close()

import sqliteio

database = sqliteio.open('/path/to/db_name.sqlite')

(... operations to database)

database.close()

open() as read only file.

f = open("/path/to/db_name.sqlite", "rb")
database = sqliteio.open(f)

You can also open() with a BytesIO instance or something byte stream generator.

with open("/path/to/db_name.sqlite", "rb") as f:
    bytesio = io.BytesIO(f.read())
    database = sqliteio.open(bytesio)

Fetch all records

Retrieve all data in a table.

for rowid_record in database.fetch_all("table_name"):
    (rowid, r) = rowid_record
    print(rowid)    # print rowid
    print(r)        # print record dict

Get by rowid

Retrieve a record using rowid.

Returns None if there is no record for the rowid.

rowid_record = database.get_by_rowid("table_name", 10)
assert rowid_record[0] == 10
print(r)        # print record dict

Get by Primary Key

Retrieve a record using Primary Key.

Returns None if there is no record for the primary key.

rowid, r = database.get_by_pk("table_name", 10)
assert rowid == 10
print(r)

Filter by index

Retrieve the target record using the index name.

index_schema = database.get_index_schema_by_name("index_name")
index_key = {
    "column1': 1,
    "column2": "str",
}
for rowid_record in database.filter_by_index(index_schema, index_key):
    (rowid, r) = rowid_record
    print(rowid)    # print rowid
    print(r)        # print record dict

Insert

Insert using dictionary list data.

r1 = {
    'pk_column': None,
    'column1': 1,
    'column2': 'string1',
}
r2 = {
    'pk_column': None,
    'column1': 2,
    'column2': 'string2',
}

database.insert("table_name", [r1, r2])

Delete

Deletion by rowid. In other words, sqliteio only has the ability to delete one row at a time.

database.delete_by_rowid("test_table", 1)

Update

Update by rowid. In other words, sqliteio only has the ability to update one row at a time.

update_data = {
    'column1': 10,
    'column2': 'new_data',
}
database.update_by_rowid("test_table", 1, update_data)

Commit & Rollback

With Insert, Delete and Update, only the data in memory can be changed and reflected in the file with commit(). To discard changes, use rollback().

database.commit()

database.rollback()

Documents on the web

• https://www.sqlite.org/fileformat2.html

• https://fly.io/blog/sqlite-internals-btree/

Repository

• https://github.com/alicebob/sqlittle

Book

• Alex Petrov, A Deep Dive into How Distributed Data Systems Work, O’Reilly Media, Inc. 2019 (chapter 3,4)