n24q02m commented on code in PR #499: URL: https://github.com/apache/hugegraph-doc/pull/499#discussion_r4107944665
########## content/en/docs/language/cypher-compatibility.md: ########## @@ -0,0 +1,59 @@ +--- +title: "Cypher Compatibility" +linkTitle: "Cypher Compatibility" +weight: 3 +--- + +### Scope of this page + +HugeGraph executes Cypher by translating statements to Gremlin through the +[`cypher-for-gremlin`](https://github.com/opencypher/cypher-for-gremlin) +transpiler (`org.opencypher.gremlin:translation:1.0.4`, released 2019-11-05). +Cypher coverage in HugeGraph therefore equals what that translator implements +of openCypher 9 — see [HugeGraph Cypher](/docs/language/hugegraph-cypher/) for +usage and [Known limitations](/docs/language/hugegraph-cypher/#known-limitations) +for the short list. + +The transpiler's own conformance self-report for 1.0.4 is **879 pass / 79 fail +(~91.7%)** of the openCypher TCK scenario set it targets. The matrix below +classifies features by the best available evidence; rows are not a substitute +for testing your own workload. + +### Feature matrix + +| openCypher feature | Status | Evidence tier | Notes / Gremlin workaround | +|---|---|---|---| +| `MATCH` + `WHERE` + `RETURN` (node patterns) | ✅ Works | Documented examples | [Language guide](/docs/language/hugegraph-cypher/) | +| Relationship patterns `(a)-[:KNOWS]->(b)` | ✅ Works | Documented examples | — | +| `ORDER BY` / `LIMIT` / `SKIP` | ✅ Works | Documented examples | — | +| `CREATE` vertex / edge, `SET` / `REMOVE`, `DELETE` / `DETACH DELETE` | ✅ Works | Documented examples | — | +| Aggregations (`count`, `sum`, `min`, `max`, `avg`) | ✅ Works | Documented examples | — | +| `MERGE` (basic) | ⚠️ Partial | Transpiler report | `MERGE ... ON CREATE SET` / `ON MATCH SET` not translated → check-then-create pattern via Gremlin | +| Variable-length paths `(a)-[:KNOWS*1..3]->(b)` | ⚠️ Untested | — | Prefer `traverser` REST APIs (k-out, paths) or Gremlin `repeat()` | +| `OPTIONAL MATCH`, `WITH`, `UNWIND` | ⚠️ Untested | — | Test before relying on them; fall back to Gremlin | +| String / math functions | ⚠️ Partial | Transpiler report | Subset of openCypher 9 functions; unsupported ones fail at translation time | +| `date()` / `datetime()` functions | ❌ Not supported | Issue reports | Compute timestamps client-side and pass as literal values | +| Regex `=~` and `NOT (... IN ...)` forms | ❌ Not supported | Issue reports | Filter client-side or via Gremlin predicates (`TextP.regex`) | Review Comment: The page has since been restructured into a verification record (2d6b627), so the stale not-supported rows are gone. The guide now states that `MERGE ... ON CREATE SET`, `=~` and `NOT ... IN` translate but are not verified end-to-end on HugeGraph, keeping only map projections and `datetime()` as translation failures (EN + CN). Fixed in debb318. ########## content/en/docs/language/cypher-compatibility.md: ########## @@ -0,0 +1,59 @@ +--- +title: "Cypher Compatibility" +linkTitle: "Cypher Compatibility" +weight: 3 +--- + +### Scope of this page + +HugeGraph executes Cypher by translating statements to Gremlin through the +[`cypher-for-gremlin`](https://github.com/opencypher/cypher-for-gremlin) +transpiler (`org.opencypher.gremlin:translation:1.0.4`, released 2019-11-05). +Cypher coverage in HugeGraph therefore equals what that translator implements +of openCypher 9 — see [HugeGraph Cypher](/docs/language/hugegraph-cypher/) for +usage and [Known limitations](/docs/language/hugegraph-cypher/#known-limitations) +for the short list. + +The transpiler's own conformance self-report for 1.0.4 is **879 pass / 79 fail +(~91.7%)** of the openCypher TCK scenario set it targets. The matrix below +classifies features by the best available evidence; rows are not a substitute +for testing your own workload. + +### Feature matrix + +| openCypher feature | Status | Evidence tier | Notes / Gremlin workaround | +|---|---|---|---| +| `MATCH` + `WHERE` + `RETURN` (node patterns) | ✅ Works | Documented examples | [Language guide](/docs/language/hugegraph-cypher/) | +| Relationship patterns `(a)-[:KNOWS]->(b)` | ✅ Works | Documented examples | — | +| `ORDER BY` / `LIMIT` / `SKIP` | ✅ Works | Documented examples | — | +| `CREATE` vertex / edge, `SET` / `REMOVE`, `DELETE` / `DETACH DELETE` | ✅ Works | Documented examples | — | +| Aggregations (`count`, `sum`, `min`, `max`, `avg`) | ✅ Works | Documented examples | — | +| `MERGE` (basic) | ⚠️ Partial | Transpiler report | `MERGE ... ON CREATE SET` / `ON MATCH SET` not translated → check-then-create pattern via Gremlin | +| Variable-length paths `(a)-[:KNOWS*1..3]->(b)` | ⚠️ Untested | — | Prefer `traverser` REST APIs (k-out, paths) or Gremlin `repeat()` | +| `OPTIONAL MATCH`, `WITH`, `UNWIND` | ⚠️ Untested | — | Test before relying on them; fall back to Gremlin | +| String / math functions | ⚠️ Partial | Transpiler report | Subset of openCypher 9 functions; unsupported ones fail at translation time | +| `date()` / `datetime()` functions | ❌ Not supported | Issue reports | Compute timestamps client-side and pass as literal values | +| Regex `=~` and `NOT (... IN ...)` forms | ❌ Not supported | Issue reports | Filter client-side or via Gremlin predicates (`TextP.regex`) | +| Map projection `n { .name, .age }` | ❌ Not supported | Issue reports | Return the node or explicit properties | +| Query parameters (`$param`) | ❌ Not supported | API surface (`CypherAPI` accepts statement string only) | Escape/sanitize values client-side before interpolating | +| `CALL` procedures (graph algorithms) | ❌ Not supported | API surface | Use [traverser REST APIs](/docs/clients/restful-api/traverser/) or Gremlin | +| Multi-statement scripts | ❌ Not supported | API surface | One statement per request | +| Schema DDL in Cypher (`CREATE INDEX`, constraints) | ❌ Not supported | Architecture | Create schema via the [schema REST APIs](/docs/clients/restful-api/schema/) | +| `EXPLAIN` / `PROFILE` | ❌ Not supported | API surface | Use Gremlin `profile()` on the traversal API | Review Comment: The restructured page records only what the dev change verified, so `EXPLAIN`/`PROFILE` stay in its unverified list. The guide now documents `EXPLAIN` support on the API (translated Gremlin returned in `result.data[0].translation`) with `PROFILE` unsupported (EN + CN). Fixed in debb318. ########## content/en/docs/language/migrate-from-neo4j.md: ########## @@ -0,0 +1,60 @@ +--- +title: "Migrating from Neo4j" +linkTitle: "Migrating from Neo4j" +weight: 4 +--- + +### Who this page is for + +Neo4j users evaluating HugeGraph. HugeGraph's Cypher coverage is defined by +the [`cypher-for-gremlin`](https://github.com/opencypher/cypher-for-gremlin) +translator and is not 1:1 with Neo4j — see the +[Cypher compatibility matrix](/docs/language/cypher-compatibility/) for the +feature-level differences and +[HugeGraph Cypher](/docs/language/hugegraph-cypher/) for usage. + +### What carries over directly + +| Neo4j concept | HugeGraph equivalent | +|---|---| +| Property graph model (nodes / relationships / properties) | Same — vertex labels / edge labels / properties | +| Core Cypher: `MATCH`/`WHERE`/`RETURN`/`CREATE`/`SET`/`DELETE` | Works as-is (REST `/cypher` endpoint or Java client `CypherManager`) | +| Simple aggregations (`count`/`sum`/`min`/`max`/`avg`) | Works as-is | +| Traversal-heavy queries | Gremlin traversals or the [traverser REST APIs](/docs/clients/restful-api/traverser/) (k-out, shortest path, personalrank, ...) | + +### Habits you need to change + +| In Neo4j | In HugeGraph | +|---|---| +| `CREATE INDEX` / `CREATE CONSTRAINT` | Create indexes/constraints through the [schema REST APIs](/docs/clients/restful-api/schema/); Cypher carries no DDL | +| Implicit schema (add properties freely) | **Strong schema**: define VertexLabel / EdgeLabel / PropertyKey before writing data | +| Parameterized queries `$param` | Not supported — escape/validate values client-side and interpolate literals | +| `CALL dbms.*` / `CALL algo.*` procedures | Equivalent capabilities live in the [traverser](/docs/clients/restful-api/traverser/), [task](/docs/clients/restful-api/task/), and other REST APIs | +| Driver: Neo4j Bolt driver | [hugegraph-client](/docs/clients/hugegraph-client/) (`CypherManager`) or any HTTP client | +| Transaction boundaries inside a Cypher statement | One statement per request; bulk writes use the [Loader](/docs/guides/toolchain/) or bulkport | Review Comment: Fixed in debb318: Loader links now point to `/docs/quickstart/toolchain/hugegraph-loader/` (and `/cn/docs/quickstart/toolchain/hugegraph-loader/`), and the undefined `bulkport` is removed. ########## content/en/docs/language/hugegraph-cypher.md: ########## @@ -0,0 +1,135 @@ +--- +title: "HugeGraph Cypher" +linkTitle: "Cypher Query Language" +weight: 2 +--- + +### Overview + +HugeGraph supports [Cypher](https://opencypher.org/), the declarative graph query language originally created by Neo4j and standardized as [openCypher](https://github.com/opencypher/openCypher). While Gremlin is an imperative traversal language, Cypher lets you describe the graph pattern you want (`MATCH`, `WHERE`, `RETURN`) and lets the engine decide how to execute it. + +HugeGraph executes Cypher by translating the statement to Gremlin through the [cypher-for-gremlin](https://github.com/opencypher/cypher-for-gremlin) transpiler, then running the resulting traversal on the TinkerPop stack. This means Cypher support in HugeGraph covers the openCypher 9 surface that the transpiler implements — see [Known limitations](#known-limitations) below. + +### When to use Cypher vs Gremlin + +| Use Cypher when | Use Gremlin when | +|---|---| +| You are migrating from Neo4j or already know Cypher | You need the full HugeGraph feature surface | +| You want declarative pattern matching (`MATCH (a)-[:KNOWS]->(b)`) | You need fine-grained traversal control, custom steps, or lambdas | +| Your queries are read-mostly patterns and projections | You need graph algorithms, OLAP, or features Cypher does not expose | + +For anything Cypher cannot express, the equivalent Gremlin query always works — examples below show both. + +### Calling the Cypher API + +Cypher statements are submitted to the HugeGraph Server through the REST endpoint: + +```http +GET /graphspaces/{graphspace}/graphs/{graph}/cypher?cypher={statement} +POST /graphspaces/{graphspace}/graphs/{graph}/cypher +``` + +The endpoint always requires an `Authorization` header (`Basic` or `Bearer`), even when server authentication is disabled — the credentials are forwarded to the Gremlin Server. See the [Cypher REST API reference](/docs/clients/restful-api/cypher/) for the full request/response format. + +Example: + +```bash +curl -H "Authorization: Bearer $TOKEN" \ + "http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/cypher?cypher=MATCH%20(n:person)%20RETURN%20n.name%20LIMIT%2010" +``` + +From the Java client, use `CypherManager` (see [hugegraph-client](/docs/clients/hugegraph-client/)): + +```java +ResultSet resultSet = hugeClient.cypher().execute("MATCH (n:person) RETURN n.name LIMIT 10"); +``` + +### Basic examples + +The examples below assume a graph with `person` vertices (`name`, `age`, `city` properties) and `knows` edges. + +#### Read — MATCH / WHERE / RETURN + +```cypher +// All persons named "marko" +MATCH (n:person) WHERE n.name = 'marko' RETURN n + +// Projection with ordering and limit +MATCH (n:person) +WHERE n.age > 30 +RETURN n.name AS name, n.age AS age +ORDER BY age DESC +LIMIT 10 + +// Relationship pattern +MATCH (a:person)-[:knows]->(b:person) +WHERE a.name = 'marko' +RETURN b.name AS friend +``` + +#### Create — CREATE + +```cypher +// Create a vertex +CREATE (n:person {name: 'josh', age: 32, city: 'beijing'}) + +// Create two vertices and an edge between them +CREATE (a:person {name: 'peter'})-[:knows]->(b:person {name: 'lop'}) +``` + +#### Update — SET / REMOVE + +```cypher +MATCH (n:person) WHERE n.name = 'josh' +SET n.age = 33 +REMOVE n.city +``` + +#### Delete — DELETE / DETACH DELETE + +```cypher +// Delete an edge +MATCH (a:person)-[r:knows]->(b:person) +WHERE a.name = 'peter' AND b.name = 'lop' +DELETE r + +// Delete a vertex and all its edges +MATCH (n:person) WHERE n.name = 'josh' +DETACH DELETE n +``` + +#### Aggregation + +```cypher +MATCH (n:person) RETURN count(n) AS total +MATCH (n:person) RETURN n.city AS city, count(*) AS cnt ORDER BY cnt DESC +``` + +### Gremlin equivalents + +Every Cypher statement is translated to Gremlin internally. When a Cypher feature is unsupported, write the traversal directly: + +| Cypher | Gremlin equivalent | +|---|---| +| `MATCH (n:person) WHERE n.name='marko' RETURN n` | `g.V().hasLabel('person').has('name','marko')` | +| `MATCH (a)-[:knows]->(b) RETURN b` | `g.V().out('knows')` | +| `CREATE (n:person {name:'x'})` | `g.addV('person').property('name','x')` | +| `MATCH (n) DETACH DELETE n` | `g.V().drop()` | +| `MATCH (n:person) RETURN count(n)` | `g.V().hasLabel('person').count()` | + +### Known limitations + +Cypher support in HugeGraph is bounded by the transpiler layer, which is based on openCypher 9 era tooling. Known gaps: + +- **No parameterized queries** — the API accepts a raw statement string only; `$param` placeholders are not supported. Sanitize/escape values on the client side before interpolating them into the statement. Review Comment: Fixed in debb318 (EN + CN): the guide now says the statement still runs, the missing binding evaluates to `null` and the query returns no rows (or writes null values), with a pointer to the JSON-bound form landing in #238. ########## content/cn/docs/language/hugegraph-cypher.md: ########## @@ -0,0 +1,135 @@ +--- +title: "HugeGraph Cypher" +linkTitle: "Cypher 查询语言" +weight: 2 +--- + +### 概述 + +HugeGraph 支持 [Cypher](https://opencypher.org/) —— 最初由 Neo4j 创建、并由 [openCypher](https://github.com/opencypher/openCypher) 标准化的声明式图查询语言。Gremlin 是命令式的遍历语言，而 Cypher 只需描述想要的图模式（`MATCH`、`WHERE`、`RETURN`），由引擎决定如何执行。 + +HugeGraph 通过 [cypher-for-gremlin](https://github.com/opencypher/cypher-for-gremlin) 转译器将 Cypher 语句翻译为 Gremlin，再在 TinkerPop 技术栈上执行。因此 HugeGraph 的 Cypher 能力覆盖转译器所实现的 openCypher 9 语法面 —— 详见下文[已知限制](#已知限制)。 + +### 何时用 Cypher、何时用 Gremlin + +| 适合用 Cypher | 适合用 Gremlin | +|---|---| +| 正在从 Neo4j 迁移，或已熟悉 Cypher | 需要 HugeGraph 的完整功能面 | +| 需要声明式模式匹配（`MATCH (a)-[:KNOWS]->(b)`） | 需要精细的遍历控制、自定义步骤或 lambda | +| 查询以读模式和投影为主 | 需要图算法、OLAP 或 Cypher 未暴露的功能 | + +凡是 Cypher 表达不了的，等价的 Gremlin 查询总是可用 —— 下文示例同时给出两种写法。 + +### 调用 Cypher API + +Cypher 语句通过 HugeGraph Server 的 REST 端点提交： + +```http +GET /graphspaces/{graphspace}/graphs/{graph}/cypher?cypher={statement} +POST /graphspaces/{graphspace}/graphs/{graph}/cypher +``` + +该端点始终要求 `Authorization` 头（`Basic` 或 `Bearer`），即使服务端未开启认证 —— 凭据会被转发给 Gremlin Server。完整的请求/响应格式见 [Cypher REST API 参考](/cn/docs/clients/restful-api/cypher/)。 + +示例： + +```bash +curl -H "Authorization: Bearer $TOKEN" \ + "http://localhost:8080/graphspaces/DEFAULT/graphs/hugegraph/cypher?cypher=MATCH%20(n:person)%20RETURN%20n.name%20LIMIT%2010" +``` + +Java 客户端使用 `CypherManager`（见 [hugegraph-client](/cn/docs/clients/hugegraph-client/)）： + +```java +ResultSet resultSet = hugeClient.cypher().execute("MATCH (n:person) RETURN n.name LIMIT 10"); +``` + +### 基础示例 + +以下示例假设图中存在 `person` 顶点（`name`、`age`、`city` 属性）和 `knows` 边。 + +#### 查询 — MATCH / WHERE / RETURN + +```cypher +// 所有名为 "marko" 的 person +MATCH (n:person) WHERE n.name = 'marko' RETURN n + +// 投影 + 排序 + 限制条数 +MATCH (n:person) +WHERE n.age > 30 +RETURN n.name AS name, n.age AS age +ORDER BY age DESC +LIMIT 10 + +// 关系模式 +MATCH (a:person)-[:knows]->(b:person) +WHERE a.name = 'marko' +RETURN b.name AS friend +``` + +#### 创建 — CREATE + +```cypher +// 创建顶点 +CREATE (n:person {name: 'josh', age: 32, city: 'beijing'}) + +// 创建两个顶点及它们之间的边 +CREATE (a:person {name: 'peter'})-[:knows]->(b:person {name: 'lop'}) +``` + +#### 更新 — SET / REMOVE + +```cypher +MATCH (n:person) WHERE n.name = 'josh' +SET n.age = 33 +REMOVE n.city +``` + +#### 删除 — DELETE / DETACH DELETE + +```cypher +// 删除边 +MATCH (a:person)-[r:knows]->(b:person) +WHERE a.name = 'peter' AND b.name = 'lop' +DELETE r + +// 删除顶点及其所有边 +MATCH (n:person) WHERE n.name = 'josh' +DETACH DELETE n +``` + +#### 聚合 + +```cypher +MATCH (n:person) RETURN count(n) AS total +MATCH (n:person) RETURN n.city AS city, count(*) AS cnt ORDER BY cnt DESC +``` + +### 等价的 Gremlin 写法 + +每条 Cypher 语句在内部都会被翻译为 Gremlin。当某个 Cypher 特性不受支持时，可直接编写遍历： + +| Cypher | 等价 Gremlin | +|---|---| +| `MATCH (n:person) WHERE n.name='marko' RETURN n` | `g.V().hasLabel('person').has('name','marko')` | +| `MATCH (a)-[:knows]->(b) RETURN b` | `g.V().out('knows')` | +| `CREATE (n:person {name:'x'})` | `g.addV('person').property('name','x')` | +| `MATCH (n) DETACH DELETE n` | `g.V().drop()` | +| `MATCH (n:person) RETURN count(n)` | `g.V().hasLabel('person').count()` | + +### 已知限制 + +HugeGraph 的 Cypher 能力受转译层约束，该层基于 openCypher 9 时代的工具链。已知缺口： + +- **不支持参数化查询** —— API 只接受原始语句字符串，不支持 `$param` 占位符。请在客户端先对值做转义/净化再拼接到语句中。 Review Comment: Reworded in debb318: released-version behavior is kept (raw statement only) with the null-evaluation caveat spelled out, and the JSON POST binding form is documented as landing in #238. ########## content/cn/docs/language/migrate-from-neo4j.md: ########## @@ -0,0 +1,53 @@ +--- +title: "从 Neo4j 迁移" +linkTitle: "从 Neo4j 迁移" +weight: 4 +--- + +### 本页面向谁 + +正在评估 HugeGraph 的 Neo4j 用户。HugeGraph 的 Cypher 覆盖面由 +[cypher-for-gremlin](https://github.com/opencypher/cypher-for-gremlin) 转译器决定， +与 Neo4j 并非 1:1 等价 —— 逐项差异见 +[Cypher 兼容性矩阵](/cn/docs/language/cypher-compatibility/)， +用法见 [HugeGraph Cypher](/cn/docs/language/hugegraph-cypher/)。 + +### 可以直接带过来的部分 + +| Neo4j 概念 | HugeGraph 对应 | +|---|---| +| 属性图模型（节点/关系/属性） | 相同 —— 顶点标签 / 边标签 / 属性 | +| 基础 Cypher：`MATCH`/`WHERE`/`RETURN`/`CREATE`/`SET`/`DELETE` | 直接可用（REST `/cypher` 端点或 Java 客户端 `CypherManager`） | +| 简单聚合（`count`/`sum`/`min`/`max`/`avg`） | 直接可用 | +| 依赖图遍历的查询需求 | Gremlin 遍历或 [traverser REST API](/cn/docs/clients/restful-api/traverser/)（k-out、最短路、personalrank 等） | + +### 需要改变习惯的部分 + +| 在 Neo4j 里 | 在 HugeGraph 里 | +|---|---| +| `CREATE INDEX` / `CREATE CONSTRAINT` | 通过 [schema REST API](/cn/docs/clients/restful-api/schema/) 建索引/约束；Cypher 不承载 DDL | +| 隐式 schema（属性随意添加） | **强 schema**：先定义 VertexLabel/EdgeLabel/PropertyKey，再写数据 | +| 参数化查询 `$param` | 暂不支持 —— 在客户端转义/校验后拼接字面量 | Review Comment: Reworded in debb318 to the null-evaluation contract with a #238 pointer instead of interpolation advice. ########## content/cn/docs/language/migrate-from-neo4j.md: ########## @@ -0,0 +1,53 @@ +--- +title: "从 Neo4j 迁移" +linkTitle: "从 Neo4j 迁移" +weight: 4 +--- + +### 本页面向谁 + +正在评估 HugeGraph 的 Neo4j 用户。HugeGraph 的 Cypher 覆盖面由 +[cypher-for-gremlin](https://github.com/opencypher/cypher-for-gremlin) 转译器决定， +与 Neo4j 并非 1:1 等价 —— 逐项差异见 +[Cypher 兼容性矩阵](/cn/docs/language/cypher-compatibility/)， +用法见 [HugeGraph Cypher](/cn/docs/language/hugegraph-cypher/)。 + +### 可以直接带过来的部分 + +| Neo4j 概念 | HugeGraph 对应 | +|---|---| +| 属性图模型（节点/关系/属性） | 相同 —— 顶点标签 / 边标签 / 属性 | +| 基础 Cypher：`MATCH`/`WHERE`/`RETURN`/`CREATE`/`SET`/`DELETE` | 直接可用（REST `/cypher` 端点或 Java 客户端 `CypherManager`） | +| 简单聚合（`count`/`sum`/`min`/`max`/`avg`） | 直接可用 | +| 依赖图遍历的查询需求 | Gremlin 遍历或 [traverser REST API](/cn/docs/clients/restful-api/traverser/)（k-out、最短路、personalrank 等） | + +### 需要改变习惯的部分 + +| 在 Neo4j 里 | 在 HugeGraph 里 | +|---|---| +| `CREATE INDEX` / `CREATE CONSTRAINT` | 通过 [schema REST API](/cn/docs/clients/restful-api/schema/) 建索引/约束；Cypher 不承载 DDL | +| 隐式 schema（属性随意添加） | **强 schema**：先定义 VertexLabel/EdgeLabel/PropertyKey，再写数据 | +| 参数化查询 `$param` | 暂不支持 —— 在客户端转义/校验后拼接字面量 | +| `CALL dbms.*` / `CALL algo.*` 过程 | 对应功能分散在 [traverser](/cn/docs/clients/restful-api/traverser/)、[task](/cn/docs/clients/restful-api/task/) 等 REST API | +| 驱动：Neo4j Bolt driver | [hugegraph-client](/cn/docs/clients/hugegraph-client/)（`CypherManager`）或任意 HTTP 客户端 | +| 事务边界在 Cypher 语句内 | 每次请求一个语句；批量写入用 [Loader](/cn/docs/guides/toolchain/) 或 bulkport | + +### 建议的迁移路径 + +1. **盘点查询**：把应用里的 Cypher 按 + [兼容性矩阵](/cn/docs/language/cypher-compatibility/) 分成 + "直接可用 / 需改写为 Gremlin / 需换 REST API" 三类。 +2. **先建 schema**：用 schema API 建好 VertexLabel/EdgeLabel/PropertyKey 和索引 —— + HugeGraph 在写入前要求 schema 存在。 +3. **导入数据**：小数据集用 REST；大批量用 + [HugeGraph Loader](https://github.com/apache/hugegraph-toolchain/tree/master/hugegraph-loader)。 +4. **灰度切换**：Cypher 能表达的查询保持不动， translator 不支持的改写为 + Gremlin（等价写法见 [对照表](/cn/docs/language/hugegraph-cypher/#等价的-gremlin-写法)）。 + +### 已知限制速查 + +- Cypher 语句不支持参数绑定、多语句脚本与 `CALL` 过程。 Review Comment: Fixed in debb318: parameter binding is now qualified by version instead of listed as unsupported; the list keeps multi-statement scripts and `CALL` procedures. -- This is an automated message from the Apache Git Service. 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