4.7. Make an in-memory database

connect_memdb() function can create a SQLite database in memory. This function return SimpleSQLite instance, the instance can execute methods as well as a SimpleSQLite instance opened with write mode.

Sample Code:

Make an in-memory database and create a table in the database

import simplesqlite


table_name = "sample_table"
con = simplesqlite.connect_memdb()

# create table -----
data_matrix = [[1, 1.1, "aaa", 1, 1], [2, 2.2, "bbb", 2.2, 2.2], [3, 3.3, "ccc", 3, "ccc"]]
con.create_table_from_data_matrix(
    table_name,
    ["attr_a", "attr_b", "attr_c", "attr_d", "attr_e"],
    data_matrix,
)

# display data type for each column in the table -----
print(con.schema_extractor.fetch_table_schema(table_name).dumps())

# display values in the table -----
print("records:")
result = con.select(select="*", table_name=table_name)
for record in result.fetchall():
    print(record)

Output:

.. table:: sample_table

    +---------+-------+-----------+--------+------+-----+
    |Attribute| Type  |PRIMARY KEY|NOT NULL|UNIQUE|Index|
    +=========+=======+===========+========+======+=====+
    |attr_a   |INTEGER|           |        |      |     |
    +---------+-------+-----------+--------+------+-----+
    |attr_b   |REAL   |           |        |      |     |
    +---------+-------+-----------+--------+------+-----+
    |attr_c   |TEXT   |           |        |      |     |
    +---------+-------+-----------+--------+------+-----+
    |attr_d   |REAL   |           |        |      |     |
    +---------+-------+-----------+--------+------+-----+
    |attr_e   |TEXT   |           |        |      |     |
    +---------+-------+-----------+--------+------+-----+


records:
(1, 1.1, 'aaa', 1.0, '1')
(2, 2.2, 'bbb', 2.2, '2.2')
(3, 3.3, 'ccc', 3.0, 'ccc')