sqliteschema 1.3.0

A Python library to dump table schema of a SQLite database file.

sqliteschema

• Summary

• Installation

  • Install from PyPI

  • Install from PPA (for Ubuntu)

• Usage

  • Extract SQLite Schemas as dict

  • Extract SQLite Schemas as Tabular Text

  • Extract SQLite Schemas as Text

• Dependencies

  • Optional dependencies

Summary

sqliteschema is a Python library to dump table schema of a SQLite database file.

Installation

Install from PyPI

pip install sqliteschema

Install optional dependencies

pip install sqliteschema[dumps]  # to use dumps method
pip install sqliteschema[logging]  # to use logging

Install from PPA (for Ubuntu)

sudo add-apt-repository ppa:thombashi/ppa
sudo apt update
sudo apt install python3-sqliteschema

Usage

Full example can be found at examples/get_table_schema.py

Extract SQLite Schemas as dict

Sample Code:

import json
import sqliteschema

extractor = sqliteschema.SQLiteSchemaExtractor(sqlite_db_path)

print("--- dump all of the table schemas with a dictionary ---\n{}\n".format(
    json.dumps(extractor.fetch_database_schema_as_dict(), indent=4)))

print("--- dump a specific table schema with a dictionary ---\n{}\n".format(
    json.dumps(extractor.fetch_table_schema("sampletable1").as_dict(), indent=4)))

Output:

--- dump all of the table schemas with a dictionary ---
{
    "sampletable0": [
        {
            "Field": "attr_a",
            "Index": false,
            "Type": "INTEGER",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        },
        {
            "Field": "attr_b",
            "Index": false,
            "Type": "INTEGER",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        }
    ],
    "sampletable1": [
        {
            "Field": "foo",
            "Index": true,
            "Type": "INTEGER",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        },
        {
            "Field": "bar",
            "Index": false,
            "Type": "REAL",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        },
        {
            "Field": "hoge",
            "Index": true,
            "Type": "TEXT",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        }
    ],
    "constraints": [
        {
            "Field": "primarykey_id",
            "Index": true,
            "Type": "INTEGER",
            "Null": "YES",
            "Key": "PRI",
            "Default": "NULL",
            "Extra": ""
        },
        {
            "Field": "notnull_value",
            "Index": false,
            "Type": "REAL",
            "Null": "NO",
            "Key": "",
            "Default": "",
            "Extra": ""
        },
        {
            "Field": "unique_value",
            "Index": true,
            "Type": "INTEGER",
            "Null": "YES",
            "Key": "UNI",
            "Default": "NULL",
            "Extra": ""
        }
    ]
}

--- dump a specific table schema with a dictionary ---
{
    "sampletable1": [
        {
            "Field": "foo",
            "Index": true,
            "Type": "INTEGER",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        },
        {
            "Field": "bar",
            "Index": false,
            "Type": "REAL",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        },
        {
            "Field": "hoge",
            "Index": true,
            "Type": "TEXT",
            "Null": "YES",
            "Key": "",
            "Default": "NULL",
            "Extra": ""
        }
    ]
}

Extract SQLite Schemas as Tabular Text

Table schemas can be output with dumps method. dumps method requires an extra package and that can install as follows:

pip install sqliteschema[dumps]

Usage is as follows:

Sample Code:

import sqliteschema

extractor = sqliteschema.SQLiteSchemaExtractor(sqlite_db_path)

for verbosity_level in range(2):
    print("--- dump all of the table schemas with a tabular format: verbosity_level={} ---".format(
        verbosity_level))
    print(extractor.dumps(output_format="markdown", verbosity_level=verbosity_level))

for verbosity_level in range(2):
    print("--- dump a specific table schema with a tabular format: verbosity_level={} ---".format(
        verbosity_level))
    print(extractor.fetch_table_schema("sampletable1").dumps(
        output_format="markdown", verbosity_level=verbosity_level))

Output:

--- dump all of the table schemas with a tabular format: verbosity_level=0 ---
# sampletable0
| Field  |  Type   |
| ------ | ------- |
| attr_a | INTEGER |
| attr_b | INTEGER |

# sampletable1
| Field |  Type   |
| ----- | ------- |
| foo   | INTEGER |
| bar   | REAL    |
| hoge  | TEXT    |

# constraints
|     Field     |  Type   |
| ------------- | ------- |
| primarykey_id | INTEGER |
| notnull_value | REAL    |
| unique_value  | INTEGER |

--- dump all of the table schemas with a tabular format: verbosity_level=1 ---
# sampletable0
| Field  |  Type   | Null | Key | Default | Index | Extra |
| ------ | ------- | ---- | --- | ------- | :---: | ----- |
| attr_a | INTEGER | YES  |     | NULL    |       |       |
| attr_b | INTEGER | YES  |     | NULL    |       |       |

# sampletable1
| Field |  Type   | Null | Key | Default | Index | Extra |
| ----- | ------- | ---- | --- | ------- | :---: | ----- |
| foo   | INTEGER | YES  |     | NULL    |   X   |       |
| bar   | REAL    | YES  |     | NULL    |       |       |
| hoge  | TEXT    | YES  |     | NULL    |   X   |       |

# constraints
|     Field     |  Type   | Null | Key | Default | Index | Extra |
| ------------- | ------- | ---- | --- | ------- | :---: | ----- |
| primarykey_id | INTEGER | YES  | PRI | NULL    |   X   |       |
| notnull_value | REAL    | NO   |     |         |       |       |
| unique_value  | INTEGER | YES  | UNI | NULL    |   X   |       |

--- dump a specific table schema with a tabular format: verbosity_level=0 ---
# sampletable1
| Field |  Type   |
| ----- | ------- |
| foo   | INTEGER |
| bar   | REAL    |
| hoge  | TEXT    |

--- dump a specific table schema with a tabular format: verbosity_level=1 ---
# sampletable1
| Field |  Type   | Null | Key | Default | Index | Extra |
| ----- | ------- | ---- | --- | ------- | :---: | ----- |
| foo   | INTEGER | YES  |     | NULL    |   X   |       |
| bar   | REAL    | YES  |     | NULL    |       |       |
| hoge  | TEXT    | YES  |     | NULL    |   X   |       |

Extract SQLite Schemas as Text

Sample Code:

import sqliteschema

extractor = sqliteschema.SQLiteSchemaExtractor(sqlite_db_path)

for verbosity_level in range(5):
    print("--- dump all of the table schemas with text format: verbosity_level={} ---".format(
        verbosity_level))
    print(extractor.dumps(output_format="text", verbosity_level=verbosity_level) + "\n")

for verbosity_level in range(5):
    print("--- dump specific table schema with text format: verbosity_level={} ---".format(
        verbosity_level))
    print(extractor.fetch_table_schema("sampletable1").dumps(
        output_format="text", verbosity_level=verbosity_level) + "\n")

Output:

--- dump all of the table schemas with text format: verbosity_level=0 ---
sampletable0
sampletable1
constraints

--- dump all of the table schemas with text format: verbosity_level=1 ---
sampletable0 (attr_a, attr_b)
sampletable1 (foo, bar, hoge)
constraints (primarykey_id, notnull_value, unique_value)

--- dump all of the table schemas with text format: verbosity_level=2 ---
sampletable0 (attr_a INTEGER, attr_b INTEGER)
sampletable1 (foo INTEGER, bar REAL, hoge TEXT)
constraints (primarykey_id INTEGER, notnull_value REAL, unique_value INTEGER)

--- dump all of the table schemas with text format: verbosity_level=3 ---
sampletable0 (attr_a INTEGER Null, attr_b INTEGER Null)
sampletable1 (foo INTEGER Null, bar REAL Null, hoge TEXT Null)
constraints (primarykey_id INTEGER Key Null, notnull_value REAL Null, unique_value INTEGER Key Null)

--- dump all of the table schemas with text format: verbosity_level=4 ---
sampletable0 (
    attr_a INTEGER Null,
    attr_b INTEGER Null
)

sampletable1 (
    foo INTEGER Null,
    bar REAL Null,
    hoge TEXT Null
)

constraints (
    primarykey_id INTEGER Key Null,
    notnull_value REAL Null,
    unique_value INTEGER Key Null
)


--- dump specific table schema with text format: verbosity_level=0 ---
sampletable1

--- dump specific table schema with text format: verbosity_level=1 ---
sampletable1 (foo, bar, hoge)

--- dump specific table schema with text format: verbosity_level=2 ---
sampletable1 (foo INTEGER, bar REAL, hoge TEXT)

--- dump specific table schema with text format: verbosity_level=3 ---
sampletable1 (foo INTEGER Null, bar REAL Null, hoge TEXT Null)

--- dump specific table schema with text format: verbosity_level=4 ---
sampletable1 (
    foo INTEGER Null,
    bar REAL Null,
    hoge TEXT Null
)

Dependencies

• Python 3.6+

• Python package dependencies (automatically installed)

Optional dependencies

• loguru

  • Used for logging if the package installed

• pytablewriter

  • Required when getting table schemas with tabular text by dumps method