Introspect

Introspection is the process of updating the schema defined in the configuration file by introspecting a data file and then applying the changes to the sources (Databases). The introspection process is performed using the lambdaorm introspect command.

CLI

The introspect command allows you to obtain the schema from data introspection.

Running the introspect command:

lambdaorm introspect -d countries.json -n counties

This command updates the schema based on data introspection, in this case from the country.json file.

Files created:

├── countries.json
├── orm_state
│   ├── default-ddl-20240502T182117031Z-push-default.sql
│   └── default-model.json
├── docker compose.yaml
└── lambdaORM.yaml

Script the synchronization in file "default-ddl-20240502T182117031Z-push-default.sql":

CREATE TABLE CountiesLanguages (id INTEGER  AUTO_INCREMENT,languageCode VARCHAR(4) NOT NULL ,countyName VARCHAR(32) NOT NULL ,CONSTRAINT CountiesLanguages_PK PRIMARY KEY (id));
ALTER TABLE CountiesLanguages ADD CONSTRAINT CountiesLanguages_UK UNIQUE (countyName,languageCode);
CREATE TABLE Languages (code VARCHAR(4) NOT NULL ,name VARCHAR(16) NOT NULL ,CONSTRAINT Languages_PK PRIMARY KEY (code));
CREATE TABLE Regions (code VARCHAR(2) NOT NULL ,name VARCHAR(32) NOT NULL ,CONSTRAINT Regions_PK PRIMARY KEY (code));
CREATE TABLE Positions (lat DECIMAL(10,4) NOT NULL ,`long` DECIMAL(10,4) NOT NULL ,CONSTRAINT Positions_PK PRIMARY KEY (lat));
ALTER TABLE Positions ADD CONSTRAINT Positions_UK UNIQUE (`long`);
CREATE TABLE Timezones (GmtOffset INTEGER  ,name VARCHAR(32) NOT NULL ,positionLat DECIMAL(10,4) NOT NULL ,countyName VARCHAR(32) NOT NULL ,CONSTRAINT Timezones_PK PRIMARY KEY (name));
CREATE TABLE Counties (name VARCHAR(32) NOT NULL ,phoneCode INTEGER NOT NULL ,priority INTEGER NOT NULL ,regionCode VARCHAR(2) NOT NULL ,CONSTRAINT Counties_PK PRIMARY KEY (name));
ALTER TABLE Counties ADD CONSTRAINT Counties_UK UNIQUE (phoneCode);
ALTER TABLE CountiesLanguages ADD CONSTRAINT CountiesLanguages_counties_FK FOREIGN KEY (countyName) REFERENCES Counties (name);
ALTER TABLE CountiesLanguages ADD CONSTRAINT CountiesLanguages_languages_FK FOREIGN KEY (languageCode) REFERENCES Languages (code);
ALTER TABLE Timezones ADD CONSTRAINT Timezones_position_FK FOREIGN KEY (positionLat) REFERENCES Positions (lat);
ALTER TABLE Timezones ADD CONSTRAINT Timezones_counties_FK FOREIGN KEY (countyName) REFERENCES Counties (name);
ALTER TABLE Counties ADD CONSTRAINT Counties_region_FK FOREIGN KEY (regionCode) REFERENCES Regions (code);

View lab

Node

• How to run the introspect method to:
• Update the schema according to the introspected type of data.
• Synchronize the schema with the data source.
• Create files with the model status and update scripts.

import { Orm } from 'lambdaorm'
(async () => {
    const workspace = process.cwd()
    const schemaPath = workspace + '/lambdaORM.yaml'        
    const orm = new Orm(workspace)
    try{
        const data = JSON.parse( await orm.helper.fs.read(workspace + '/countries.json') || '{}')
        await orm.init(schemaPath)  
        await orm.stage.introspect(data, 'countries')
    }catch(e){
        console.log(e)
    } finally {
        await orm.end()
    }   
})()

As a result:

• The "lambdaORM.yaml" file will be updated according to the type introspected from the data.
• The updated schema is synchronized with the data source.
• Files are created with the model status and update scripts.

View lab