Taichi ORM

Select and Filter

Select target model and relations

// Simply select shop, each with array of products
let shops = await Shop.find({
  selectProps: ['products']
})
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Select target model and relations by findOptions

// find shops with related products which are only in color 'red'
let shops = await Shop.find({
  select: {
    // select the computed property 'products'
    products: {
      where: {
        color: 'red'
      }
    }
  },
  where: {
    //...
  }
})
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Select target model with relations match criteria


// find all products which belongs to a Shop
let products = await Product.find({
  where: ({root}) => root.shop().exists()
})

// find all products which belongs to Shop with location 'Hong Kong'
let products = await Product.find({
  where: ({root}) => root.shop({
    where: {
      location: 'Hong Kong'
    }
  }).exists()
})

// another approach (if the 'hasMany' relationship is not defined in Model Schema)
await Product.find({
  where: ({root, Exists}) => Exists( Shop.dataset({
    where: {
      shopId: root.id,
      location: 'Hong Kong'
    }
  }))
})
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Besides, the funtion call of ComputeProperty returns a Scalar that can be transformed into subquery like "SELECT count(*) FROM ..."

// find all shops which has more than 5 products
let shops = await Shop.find({
  where: ({root}) => root.products().count().greaterThan(5)
})

// another approach (if the 'hasMany' relationship is not defined in Model Schema)
let shops = await Shop.find({
  where: ({root}) => Product.dataset({
    where: {
      shopId: root.id
    }
  }).toDScalar().count().greaterThan(5)
})
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