View

A view model makes it easy to map an entity to a database table and query it.

To create a view, use the NewView() function.

type User struct {
    ID    int
    Name  string
    Email string
}

var userView = psql.NewView[User]("public", "users")

tip

The NewViewx() function takes an extra type parameter to determine how slices are returned.

A view model provies the following methods:

Name()

This returns a properly quoted name of the table and can be used as a bob expression. e.g. "public"."users"

NameAs()

Similar to Name(), but adds an alias. e.g. "public"."users" as "public.users"

Columns()

Returns an orm.Columns object.
This is also a bob expression. Which by default, the expression evaluates to:

-- table_alias.column_name
"public.users"."id" AS "id",
"public.users"."name" AS "name",
"public.users"."email" AS "email"

Learn about how to manipulate a columns list in the columns documentation

Query()

The Query() method starts a SELECT query on the model's database view/table. It can accept query mods to modify the final query.

q := userView.Query(
    ctx, db, 
    sm.Limit(10), // LIMIT 10
)

The query can then be executed with One(), All(), Cursor(), Count() or Exists().

// SELECT * FROM "users" LIMIT 1
userView.Query(ctx, db).One()

// SELECT * FROM "users"
userView.Query(ctx, db).All()

// Like All, but returns a cursor for moving through large results
userView.Query(ctx, db).Cursor()

// SELECT count(1) FROM "users"
userView.Query(ctx, db).Count()

// Like One(), but only returns a boolean indicating if the model was found
userView.Query(ctx, db).Exists()

tip

The Count() function clones the current query which can be an expensive operation.