hasOne and hasMany supported between data models way to associate, query by withsparameter to directly query the associated data.

Write two data models of supplier supplier and user user, one user corresponds to one supplier, and one supplier has multiple users. When querying a user, it returns the information of the supplier at the same time, and when querying a supplier, it returns the user list of the supplier at the same time.

Supplier model supplier:

User model user :

Create data table

yao migrate

Relationships are declared in relations, a data model supports multiple mapping relationship declarations, and the data structure is {"relation_name":ObjectRelation, "relation_name":ObjectRelation ,...}

Object Relation data structure:

When querying a user, the information of the supplier to which the user belongs is also returned. Modify the user model description file user.mod.json and add the hasOne association statement.

data query

At the same time when querying users, query all supplier information:

yao run models.user.Find 1 '::{"withs":{ "supplier": {} }}'
yao run models.user.Get '::{"withs":{ "supplier": {} }}'

Specify the pick field for the associated model:

yao run models.user.Find 1 '::{"withs":{ "supplier": { "select":["name"] } }}'

Query conditions by the fields of the associated model:

yao run models.user.Get '::{"withs":{ "supplier": {} }, "wheres":[{"rel":"supplier", "column":"name", "value": "Yao App Engine" }]}'

Use arbitrary associations in JS:

function test() {
  var user = Process("models.user.get", {
    withs: {
      supplier: {
        query: {
          select: ["name", "id"],
        },
      },
    },
    wheres: [{ column: "user_id", value: 1, op: "=" }],
    orders: [{ column: "id", option: "desc" }],
    limit: 1,
  });
}

When querying a supplier, the user information of the supplier is also returned. Modify the user model description file supplier.mod.json and add the hasMany relationship statement.

data query

When querying suppliers, also query the user information:

yao run models.supplier.Find 1 '::{"withs":{ "users": {} }}'
yao run models.supplier.Get '::{"withs":{ "users": {} }}'

Specify the pick field for the associated model:

yao run models.supplier.Find 1 '::{"withs":{ "users": { "select":["name"] } }}'

Specify associated user filters:

yao run models.supplier.Find 1 '::{"withs":{ "users": { "wheres":[{"column":"name", "value":"Zhang Wuji"}] } }}'

Associations support nested queries, specified through the withs query parameter.

yao run models.supplier.Find 1 '::{"withs":{ "users": { "withs": {"supplier":{} } } }}'

yao run models.supplier.Get '::{"withs":{ "users": { "withs": {"supplier":{} } } }}'