Utility for extracting information about existing DB schema
This library currently supports Postgres, MySQL, MS SQL, SQLite, and OracleDB. We aim to have support for the same databases as the main knex project.
Install the package through NPM or Yarn:
npm install knex-schema-inspector
yarn add knex-schema-inspector
The package is initialized by passing it an instance of Knex:
import Knex from 'knex';
import schemaInspector from 'knex-schema-inspector';
const database = Knex({
client: 'mysql',
connection: {
host: '127.0.0.1',
user: 'your_database_user',
password: 'your_database_password',
database: 'myapp_test',
charset: 'utf8',
},
});
const inspector = schemaInspector(database);
export default inspector;import inspector from './inspector';
async function logTables() {
const tables = await inspector.tables();
console.log(tables);
}Note: MySQL doesn't support the schema parameter, as schema and database are ambiguous in MySQL.
Note 2: Some database types might return slightly more information than others. See the type files for a specific overview what to expect from driver to driver.
Note 3: MSSQL doesn't support comment for either tables or columns
Table
tables(): Promise<string[]>tableInfo(table?: string): Promise<Table | Table[]>hasTable(table: string): Promise<boolean>
Columns
columns(table?: string): Promise<{ table: string, column: string }[]>columnInfo(table?: string, column?: string): Promise<Column[] | Column>primary(table: string): Promise<string>
Foreign Keys
Misc.
Retrieve all tables in the current database.
await inspector.tables();
// => ['articles', 'images', 'reviews']Retrieve the table info for the given table, or all tables if no table is specified
await inspector.tableInfo('articles');
// => {
// name: 'articles',
// schema: 'project',
// comment: 'Informational blog posts'
// }
await inspector.tableInfo();
// => [
// {
// name: 'articles',
// schema: 'project',
// comment: 'Informational blog posts'
// },
// { ... },
// { ... }
// ]Check if a table exists in the current database.
await inspector.hasTable('articles');
// => trueRetrieve all columns in a given table, or all columns if no table is specified
await inspector.columns();
// => [
// {
// "table": "articles",
// "column": "id"
// },
// {
// "table": "articles",
// "column": "title"
// },
// {
// "table": "images",
// "column": "id"
// }
// ]
await inspector.columns('articles');
// => [
// {
// "table": "articles",
// "column": "id"
// },
// {
// "table": "articles",
// "column": "title"
// }
// ]Retrieve all columns from a given table. Returns all columns if table parameter is undefined.
await inspector.columnInfo('articles');
// => [
// {
// name: "id",
// table: "articles",
// data_type: "VARCHAR",
// default_value: null,
// max_length: null,
// numeric_precision: null,
// numeric_scale: null,
// is_nullable: false,
// is_unique: false,
// is_primary_key: true,
// has_auto_increment: true,
// foreign_key_column: null,
// foreign_key_table: null,
// comment: "Primary key for the articles collection"
// },
// { ... },
// { ... }
// ]
await inspector.columnInfo('articles', 'id');
// => {
// name: "id",
// table: "articles",
// data_type: "VARCHAR",
// default_value: null,
// max_length: null,
// numeric_precision: null,
// numeric_scale: null,
// is_nullable: false,
// is_unique: false,
// is_primary_key: true,
// has_auto_increment: true,
// foreign_key_column: null,
// foreign_key_table: null,
// comment: "Primary key for the articles collection"
// }Retrieve the primary key column for a given table
await inspector.primary('articles');
// => "id"Retrieve all configured foreign key constraints.
await inspector.foreignKeys();
// => [
// {
// table: 'directus_files',
// column: 'folder',
// foreign_key_table: 'directus_folders',
// foreign_key_column: 'id',
// constraint_name: 'directus_files_folder_foreign',
// on_update: 'CASCADE',
// on_delete: 'SET NULL'
// },
// {
// table: 'directus_files',
// column: 'modified_by',
// foreign_key_table: 'directus_users',
// foreign_key_column: 'id',
// constraint_name: 'directus_files_modified_by_foreign',
// on_update: 'CASCADE',
// on_delete: 'SET NULL'
// }
// ]Not supported in MySQL
Set the schema to use. Note: this is set on the inspector instance and only has to be done once:
inspector.withSchema('my-schema');Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
Please make sure to update tests as appropriate.
First start docker containers:
$ docker-compose up -dThen run tests:
$ npm testStandard mocha filter (grep) can be used:
$ npm test -- -g '.tableInfo'