Building Tables

Define data models and tables in qqq

Overview

Tables are the foundation of qqq applications. They define your data models, fields, relationships, and behaviors.

Defining a Table

Tables in qqq are defined using Java classes with annotations:

Java

@QTableMetaData(name = "order", label = "Orders")
public class OrderTable implements TableMetaDataProducer {
    @Override
    public QTableMetaData produce(QInstance qInstance) {
        return new QTableMetaData()
            .withName("order")
            .withLabel("Orders")
            .withBackendName("rdbms")
            .withPrimaryKeyField("id")
            .withFields(defineFields());
    }
}

Field Types

qqq supports these field types:

Type	Description	Java Type
STRING	Text values	String
INTEGER	Whole numbers	Integer
DECIMAL	Decimal numbers	BigDecimal
BOOLEAN	True/false	Boolean
DATE	Date only	LocalDate
DATE_TIME	Date and time	Instant
BLOB	Binary data	byte[]

Relationships

Define relationships between tables using associations:

Java

.withAssociation(new Association()
    .withName("lineItems")
    .withAssociatedTableName("orderLineItem")
    .withJoinName("orderLineItemJoin"))

Validation

Add field-level validation:

Java

new QFieldMetaData("email", QFieldType.STRING)
    .withIsRequired(true)
    .withMaxLength(255)
    .withFieldBehavior(new EmailFieldBehavior())

Next Steps

Building Processes - Add business logic

qctl Commands - Generate table scaffolding