Question

我需要能够在不使用newBuilder（）的情况下运行原始字符串突变查询：

Gson gson = new Gson();
String json = gson.toJson(newEmployer);
Transaction newTransaction = this.dgraphClient.newTransaction();
Mutation mu = Mutation.newBuilder().setSetJson(ByteString.copyFromUtf8(json.toString())).build();
newTransaction.mutate(mu);

我要跑步：

String email = "ba@a.aa";
String userType = "JOB_SEEKER";
Transaction newTransaction = this.dgraphClient.newTransaction();
String query = 
        "{\n" +
        "    set { \n" +
        "       _:user <label> \"USER\" . \n" +
        "      _:user <userType> \"" + email + "\" . \n" +
        "      _:user <email> \"" + userType + "\" . \n" +
        "    }\n" +
        "}";
Mutation mu = Mutation.parseFrom(ByteString.copyFromUtf8(query));
newTransaction.mutate(mu);

但是我在运行时遇到错误：“在解析协议消息时，输入意外终止于字段中间。这可能意味着输入已被截断，或者嵌入式消息错误地报告了自己的长度。”

Answer 1

在gRPC客户端（例如dgraph4j）中为突变设置N-Quad三元组时，您仅需要指定换行符分隔的三元组并将其传递给Mutation#setSetNquads。它们没有被set包围。换句话说，代替这个：

{
  set {
    _:user <label> "USER" .
    _:user <userType> "USER_TYPE" .
    _:user <email> "ba@a.aa" .
  }
}

您只需要三元组：

_:user <label> "USER" .
_:user <userType> "USER_TYPE" .
_:user <email> "ba@a.aa" .

这是Java代码中的样子：

String email = "ba@a.aa";
String userType = "JOB_SEEKER";
Transaction newTransaction = this.dgraphClient.newTransaction();
String triples = 
        "_:user <label> \"USER\" .\n" +
        "_:user <userType> \"" + email + "\" .\n" +
        "_:user <email> \"" + userType + "\" .";
Mutation mu =
    Mutation.newBuilder()
        .setSetNquads(ByteString.copyFromUtf8(triples))
        .build();
Assigned assigned = newTransaction.mutate(mu);

第一个带有{ set { ... } }的突变格式用于HTTP客户端，其中包括Dgraph Ratel或curl内的突变。

有关Dgraph突变的更多信息，请参见突变文档：https://docs.dgraph.io/mutations/

Answer 2

我找到了一些解决方案，它不是字符串，但是可以工作。

JSONObject query = new JSONObject();
query.put("label", "USER");
query.put("userType", userType);
query.put("email", email);
Mutation mu = Mutation.newBuilder().setSetJson(ByteString.copyFromUtf8(query.toJSONString())).build();

Java中的Dgraph。如何运行原始字符串突变查询？

2 个答案: