Query Relations

Since all relations are defined via methods,and they are retrived by separate sql querys.

You can add other constraints before load relation results from database.

Add constrains use with or relationmethod

var u models.User
DB.Model(&u).With(map[string]func(builder *goeloquent.RelationBuilder) *goeloquent.RelationBuilder{
    "Posts": func(builder *goeloquent.RelationBuilder) *goeloquent.RelationBuilder {
        builder.Where("title", "like", fmt.Sprintf("%%%s%%", "struct")).OrWhere("content", "like", fmt.Sprintf("%%%s%%", "struct"))
        return builder
    },
}).Find(&u, 4)
//{select * from `users` where `id` in (?) limit 1 [4] {1} 66.970403ms}
//{select * from `posts` where `user_id` is  not null  and `user_id` in (?) and `title` like ? or `content` like ? [4 %struct% %struct%] {4} 73.976216ms}

var posts []models.Post
u.PostsRelation().Where("title", "like", fmt.Sprintf("%%%s%%", "struct")).Get(&posts) 
//{select * from `posts` where `user_id` = ? and `user_id` is  not null  and `title` like ? [4 %struct%] {1} 66.896803ms}

Load mutiple relations

var us []models.User
DB.Model(&u).With("Videos", "Posts").Find(&us, []interface{}{4, 6, 8})
//{select * from `users` where `id` in (?,?,?) [4 6 8] {3} 67.432028ms}
//{select * from `videos` where `user_id` is  not null  and `user_id` in (?,?,?) [4 6 8] {1} 73.787433ms}
//{select * from `posts` where `user_id` is  not null  and `user_id` in (?,?,?) [4 6 8] {2} 68.884461ms}

Load nested relations

DB.Model(&u).With(map[string]func(builder *goeloquent.RelationBuilder) *goeloquent.RelationBuilder{
    "Posts.Comments":func(builder *goeloquent.RelationBuilder) *goeloquent.RelationBuilder {
        builder.Where("upvote_count", ">", 0)
        return builder
    },
    "Videos.Comments":func(builder *goeloquent.RelationBuilder) *goeloquent.RelationBuilder {
        builder.Where("upvote_count", ">", 0)
        return builder
    },
}).Find(&u, 4)
//{select * from `users` where `id` in (?) limit 1 [4] {1} 65.780493ms}
//{select * from `posts` where `user_id` is  not null  and `user_id` in (?) [4] {2} 63.999841ms}
//{select * from `comments` where `commentable_id` is  not null  and `commentable_type` = ? and `commentable_id` in (?,?) and `upvote_count` > ? [post 2 12 0] {1} 63.856649ms}
//{select * from `videos` where `user_id` is  not null  and `user_id` in (?) [4] {1} 65.756311ms}
//{select * from `comments` where `commentable_id` is  not null  and `commentable_type` = ? and `commentable_id` in (?) and `upvote_count` > ? [video 2 0] {1} 68.023121ms}

Query PivotTable

In many to many relations , there is a pivot table, you can add constraints or get it . Use WherePivot and WithPivot
In previous example we have a user-role many to many relation.Below is pivot table structure

user_roles
    id - integer,
    user_id - integer
    role_id - integer
    granted_by - integer
    granted_at - timestamp
    status - integer

Query Example

var r Role
var rs []Role
_, _ = goeloquent.Eloquent.Model(&Role{}).Where("id", 12).With("Users", "UsersP").WithPivot("status","id").First(&r)
//{select * from `roles` where `id` = ? limit 1 [12] {1} 74.899725ms}
//{select `users`.*,`user_roles`.`role_id` as `goelo_pivot_role_id`,`user_roles`.`user_id` as `goelo_pivot_user_id`,`user_roles`.`status` as `goelo_pivot_status`,`user_roles`.`id` as `goelo_pivot_id` from `users` inner join user_roles on `user_roles`.`user_id` = `users`.`id` where `user_roles`.`role_id` in (?) [12] {1} 80.412644ms}

_, _ = goeloquent.Eloquent.Model(&Role{}).With("Users", "UsersP").WherePivot("granted_by", 2).WithPivot("granted_by").Get(&rs)
//{select * from `roles` [] {4} 66.349528ms}
fmt.Println(rs[0].Users[0].Pivot["goelo_pivot_granted_by"])
//{2 true} sql.NullString

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