sqliteschema 0.14.1

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

sqliteschema

• Summary

• Installation

• Usage

  • Extract SQLite Schemas as dict

  • Extract SQLite Schemas as Tabular Text

  • Extract SQLite Schemas as Text

• Dependencies

  • Optional dependencies

  • Test dependencies

Summary

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

Installation

pip install 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": [
        {
            "Attribute": "attr_a",
            "Index": false,
            "Type": "INTEGER",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        },
        {
            "Attribute": "attr_b",
            "Index": false,
            "Type": "INTEGER",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        }
    ],
    "sampletable1": [
        {
            "Attribute": "foo",
            "Index": true,
            "Type": "INTEGER",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        },
        {
            "Attribute": "bar",
            "Index": false,
            "Type": "REAL",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        },
        {
            "Attribute": "hoge",
            "Index": true,
            "Type": "TEXT",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        }
    ],
    "constraints": [
        {
            "Attribute": "primarykey_id",
            "Index": false,
            "Type": "INTEGER",
            "PRIMARY KEY": true,
            "NOT NULL": false,
            "UNIQUE": false
        },
        {
            "Attribute": "notnull_value",
            "Index": false,
            "Type": "REAL",
            "PRIMARY KEY": false,
            "NOT NULL": true,
            "UNIQUE": false
        },
        {
            "Attribute": "unique_value",
            "Index": false,
            "Type": "INTEGER",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": true
        }
    ]
}

--- dump a specific table schema with a dictionary ---
{
    "sampletable1": [
        {
            "Attribute": "foo",
            "Index": true,
            "Type": "INTEGER",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        },
        {
            "Attribute": "bar",
            "Index": false,
            "Type": "REAL",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        },
        {
            "Attribute": "hoge",
            "Index": true,
            "Type": "TEXT",
            "PRIMARY KEY": false,
            "NOT NULL": false,
            "UNIQUE": false
        }
    ]
}

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
|Attribute| Type  |
|---------|-------|
|attr_a   |INTEGER|
|attr_b   |INTEGER|


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


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


--- dump all of the table schemas with a tabular format: verbosity_level=1 ---
# sampletable0
|Attribute| Type  |PRIMARY KEY|NOT NULL|UNIQUE|Index|
|---------|-------|:---------:|:------:|:----:|:---:|
|attr_a   |INTEGER|           |        |      |     |
|attr_b   |INTEGER|           |        |      |     |

# sampletable1
|Attribute| Type  |PRIMARY KEY|NOT NULL|UNIQUE|Index|
|---------|-------|:---------:|:------:|:----:|:---:|
|foo      |INTEGER|           |        |      |  X  |
|bar      |REAL   |           |        |      |     |
|hoge     |TEXT   |           |        |      |  X  |

# constraints
|  Attribute  | Type  |PRIMARY KEY|NOT NULL|UNIQUE|Index|
|-------------|-------|:---------:|:------:|:----:|:---:|
|primarykey_id|INTEGER|     X     |        |      |     |
|notnull_value|REAL   |           |   X    |      |     |
|unique_value |INTEGER|           |        |  X   |     |

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

--- dump a specific table schema with a tabular format: verbosity_level=1 ---
# sampletable1
|Attribute| Type  |PRIMARY KEY|NOT NULL|UNIQUE|Index|
|---------|-------|:---------:|:------:|:----:|:---:|
|foo      |INTEGER|           |        |      |  X  |
|bar      |REAL   |           |        |      |     |
|hoge     |TEXT   |           |        |      |  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, attr_b INTEGER)
sampletable1 (foo INTEGER, bar REAL, hoge TEXT)
constraints (primarykey_id INTEGER PRIMARY KEY, notnull_value REAL NOT NULL, unique_value INTEGER UNIQUE)

--- dump all of the table schemas with text format: verbosity_level=4 ---
sampletable0 (
    attr_a INTEGER,
    attr_b INTEGER
)
sampletable1 (
    foo INTEGER,
    bar REAL,
    hoge TEXT
)
constraints (
    primarykey_id INTEGER PRIMARY KEY,
    notnull_value REAL NOT NULL,
    unique_value INTEGER UNIQUE
)

--- 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, bar REAL, hoge TEXT)

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

Dependencies

Python 2.7+ or 3.4+

• mbstrdecoder

• six

• tabledata

• typepy

Optional dependencies

• logbook

  • Logging using logbook if the package installed

• pytablewriter

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

Test dependencies

• pytest

• pytest-runner

• SimpleSQLite

• tox