Xata•2y ago•

6 replies

Reverse links typescript

Hi there. I'm wondering if it's possible to

read

read

ShoppingCart

ShoppingCart

by it's

id

id

and also get all it's

ShoppingCartLineItems

ShoppingCartLineItems

in one query. I'm trying to avoid making multiple queries to the database.

I've had a look at https://xata.io/blog/navigating-many-to-one and https://xata.io/docs/concepts/data-model#links-and-relationships but I'm still not sure how to do this.

Schema:

{
  "tables": [
    {
      "name": "ShoppingCarts",
      "columns": [
        {
          "name": "customerId",
          "type": "string"
        }
      ],
      "revLinks": [
        {
          "column": "shoppingCart",
          "table": "Users"
        },
        {
          "column": "shoppingCart",
          "table": "ShoppingCartLineItems"
        }
      ]
    },
    {
      "name": "ShoppingCartLineItems",
      "columns": [
        {
          "name": "shoppingCart",
          "type": "link",
          "link": {
            "table": "ShoppingCarts"
          }
        },
        {
          "name": "productId",
          "type": "string"
        },
        {
          "name": "quantity",
          "type": "int"
        },
        {
          "name": "type",
          "type": "string",
          "defaultValue": "product"
        }
      ]
    }
  ]
}

{
  "tables": [
    {
      "name": "ShoppingCarts",
      "columns": [
        {
          "name": "customerId",
          "type": "string"
        }
      ],
      "revLinks": [
        {
          "column": "shoppingCart",
          "table": "Users"
        },
        {
          "column": "shoppingCart",
          "table": "ShoppingCartLineItems"
        }
      ]
    },
    {
      "name": "ShoppingCartLineItems",
      "columns": [
        {
          "name": "shoppingCart",
          "type": "link",
          "link": {
            "table": "ShoppingCarts"
          }
        },
        {
          "name": "productId",
          "type": "string"
        },
        {
          "name": "quantity",
          "type": "int"
        },
        {
          "name": "type",
          "type": "string",
          "defaultValue": "product"
        }
      ]
    }
  ]
}

What seems to work is:

const record = await xata.db.ShoppingCarts.select([{
    name: "<-ShoppingCartLineItems.shoppingCart",
    columns: ["productId", "quantity", "type"],
    as: "lineItems"
}]).filter({ id: "rec_cno400v3e8os6tplq4jg"}).getFirstOrThrow()

const record = await xata.db.ShoppingCarts.select([{
    name: "<-ShoppingCartLineItems.shoppingCart",
    columns: ["productId", "quantity", "type"],
    as: "lineItems"
}]).filter({ id: "rec_cno400v3e8os6tplq4jg"}).getFirstOrThrow()

However,

record

record

doesn't have a

lineItems

lineItems

prop.

Reduce query round trips with improved one-to-many relations

Addressing the N+1 problem and navigating one-to-many relationships with Xata's new approach.

Data model

A relational data model with schemaful flexibility and JSON support

Reverse links typescript

Hi there. I'm wondering if it's possible to

read

read

ShoppingCart

ShoppingCart

by it's

id

id

and also get all it's

ShoppingCartLineItems

ShoppingCartLineItems

{
  "tables": [
    {
      "name": "ShoppingCarts",
      "columns": [
        {
          "name": "customerId",
          "type": "string"
        }
      ],
      "revLinks": [
        {
          "column": "shoppingCart",
          "table": "Users"
        },
        {
          "column": "shoppingCart",
          "table": "ShoppingCartLineItems"
        }
      ]
    },
    {
      "name": "ShoppingCartLineItems",
      "columns": [
        {
          "name": "shoppingCart",
          "type": "link",
          "link": {
            "table": "ShoppingCarts"
          }
        },
        {
          "name": "productId",
          "type": "string"
        },
        {
          "name": "quantity",
          "type": "int"
        },
        {
          "name": "type",
          "type": "string",
          "defaultValue": "product"
        }
      ]
    }
  ]
}

{
  "tables": [
    {
      "name": "ShoppingCarts",
      "columns": [
        {
          "name": "customerId",
          "type": "string"
        }
      ],
      "revLinks": [
        {
          "column": "shoppingCart",
          "table": "Users"
        },
        {
          "column": "shoppingCart",
          "table": "ShoppingCartLineItems"
        }
      ]
    },
    {
      "name": "ShoppingCartLineItems",
      "columns": [
        {
          "name": "shoppingCart",
          "type": "link",
          "link": {
            "table": "ShoppingCarts"
          }
        },
        {
          "name": "productId",
          "type": "string"
        },
        {
          "name": "quantity",
          "type": "int"
        },
        {
          "name": "type",
          "type": "string",
          "defaultValue": "product"
        }
      ]
    }
  ]
}

What seems to work is:

const record = await xata.db.ShoppingCarts.select([{
    name: "<-ShoppingCartLineItems.shoppingCart",
    columns: ["productId", "quantity", "type"],
    as: "lineItems"
}]).filter({ id: "rec_cno400v3e8os6tplq4jg"}).getFirstOrThrow()

const record = await xata.db.ShoppingCarts.select([{
    name: "<-ShoppingCartLineItems.shoppingCart",
    columns: ["productId", "quantity", "type"],
    as: "lineItems"
}]).filter({ id: "rec_cno400v3e8os6tplq4jg"}).getFirstOrThrow()

However,

record

record

doesn't have a

lineItems

lineItems

prop.

Reduce query round trips with improved one-to-many relations

Addressing the N+1 problem and navigating one-to-many relationships with Xata's new approach.

Data model

A relational data model with schemaful flexibility and JSON support

Reverse links typescript

Reverse links typescript

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