Entities

Entity is the most important part of the generated code. It reflects structure of the table and it relationships. Each entity gets name in format <TableName>Entity.

Basics

For example, such definition of table:

_ = pqt.NewTable("news").
	AddColumn(pqt.NewColumn("id", pqt.TypeSerial())).
	AddColumn(pqt.NewColumn("title", pqt.TypeText(), pqt.WithNotNull())).
	AddColumn(pqt.NewColumn("lead", pqt.TypeText())).
	AddColumn(pqt.NewColumn("content", pqt.TypeText(), pqt.WithNotNull())).
	AddColumn(pqt.NewColumn("created_at", pqt.TypeTimestampTZ(), pqt.WithNotNull()))
	AddColumn(pqt.NewColumn("updated_at", pqt.TypeTimestampTZ()))

will produce such entity struct:

type NewsEntity struct{
	ID int64
	Title string
	Content sql.NullString
	Content string
	CreatedAt time.Time
	UpdatedAt pq.NullTime
}

As we can see the code generated for the column that is null-able is different. The library is using Null types that are coming from sql and pq package.

Bidirectional

Entity can be aware of relationships it belongs to. To create extra properties that can hold related object(s) WithBidirectional() should be passed to the relationship definition e.g.:

news := pqt.NewTable("news")
comment := pqt.NewTable("comment")

comment.AddRelationship(pqt.ManyToOne(news, pqt.WithBidirectional()))

Such definition will produce code similar to this:

type NewsEntity struct{
	Comments []*CommentEntity
}

type CommentEntity struct {
	News *NewsEntity
}

Those properties are not populated automatically. To know more about making queries with joins visit this page.