Question

我有以下json对象：

{
  "my_items": [
    { "a": "primary", n: 1 },
    { "b": "secondary", n: 2 },
    { "b": "secondary", n: 3 }
  ]
}

my_items列表中的所有项目都应该是唯一的。现在，我需要使用以下规则验证整个json对象：

它可能包含零个或多个"type": "secondary"项，但绝对必须包含一个且只有"type": "primary"的项目。

如何使用最新的json-schema来表达？

我想出following：

var schema = {
  "definitions": {
    "primary_item": {
      "type": "object",
      "properties": {
        "a": {
          "type":"string",
          "enum":["primary"]
        }
      }
    },
    "secondary_item": {
      "type": "object",
      "properties": {
        "b": {
          "type": "string",
          "enum":["secondary"]
        }
      }
    }
  },
  "type": "object",
  "properties": {
    "my_items": {
      "type": "array",
      "minItems": 1,
      "contains": {"$ref": "#/definitions/primary_item"},
      "items": {
        "anyOf": [
          {"$ref": "#/definitions/primary_item"},
          {"$ref": "#/definitions/secondary_item"}
        ],
        "additionalProperties": false
      }
    }
  },
  "additionalProperties": false
};

var validate = ajv.compile(schema);

test({
  "my_items": [
    {"a": "primary"},
    {"b": "secondary"},
    {"b": "secondary"}
  ]
});

但测试失败，出现以下错误：

Invalid: data.my_items[0] should NOT have additional properties, data.my_items[1] should NOT have additional properties, data.my_items[2] should NOT have additional properties

Answer 1

JSON Schema中没有办法断言数组只包含一个东西。你可以声称至少有一个，但这是你能做的最好的。最接近的是要求primary_item是数组中的第一个元素。

{
  "type": "object",
  "properties": {
    "my_items": {
      "type": "array",
      "items": [
        {"$ref": "#/definitions/primary_item"}
      ],
      "additionalItems": {"$ref": "#/definitions/secondary_item"}
    }
  },
  "additionalProperties": false,
  "definitions": {
    "primary_item": {
      "type": "object",
      "properties": {
        "a": { "enum":["primary"] }
      },
      "additionalProperties": false
    },
    "secondary_item": {
      "type": "object",
      "properties": {
        "b": { "enum":["secondary"] }
      },
      "additionalProperties": false
    }
  }
}

修改

回应评论

我想知道是否可以使用两个概念表达一个且只有一个：at least one + unique。

是。如果您的数组项是唯一的，则可以执行以下操作。

{ "type": "object", "properties": { "my_items": { "type": "array", "items": { "$ref": "#/definitions/my_item" }, "allOf": [{"$ref": "#/definitions/contains_primary_item"}], "uniqueItems": true } }, "additionalProperties": false, "definitions": { "my_item": { "type": "object", "properties": { "a": { "type": "string" } }, "additionalProperties": false }, "primary_item": { "type": "object", "properties": { "a": { "enum":["primary"] } }, "additionalProperties": false }, "contains_primary_item": { "not": { "items": { "not": { "$ref": "#/definitions/primary_item" } } } } } }

需要数组中的特定项

1 个答案: