42P03 — 重复游标

游标或 portal 名称与已有的冲突。

英文手册覆盖始于 PostgreSQL 8.1. 来源历史与运行验证各自保留独立版本边界。

当前阅读 PG 18·选择有来源记录的版本

8.1 8.2 8.3 8.4 9.0 9.1 9.2 9.3 9.4 9.5 9.6 10 11 12 13 14 15 16 17 18 19 20

aliases: 未知
class name: Syntax Error or Access Rule Violation
condition name: duplicate_cursor
lang: en
sqlstate: 42P03

版本定义 PG 18

42P03 — 重复游标

速览 {#at-a-glance}

42P03（duplicate_cursor）报告游标或 portal 名称冲突，但同一 SQLSTATE 覆盖 ERROR、替换时的 WARNING，以及 PL/pgSQL 活动游标的 ERROR。调用方和 CreatePortal 选项决定具体行为。

含义 {#meaning}

CreatePortal(name, allowDup, dupSilent) 在 allowDup 为 false 时报告 ERROR cursor "%s" already exists。allowDup 为 true 时，若 dupSilent 未设置，会先发 WARNING closing existing cursor "%s"，随后删除旧 portal 并创建新 portal。PL/pgSQL 是另一条路径：SPI_cursor_find 发现同名活动游标时报告 ERROR cursor "%s" already in use。

诊断 {#diagnosis}

记录准确名称、来源（SQL portal 创建还是 PL/pgSQL OPEN）、严重性和事务状态。SQL 路径检查 portal 创建/复用及适用时的 pg_cursors；PL/pgSQL 路径检查游标变量和 OPEN/CLOSE 流程。allowDup 的替换分支不能推出所有重复声明都会 WARNING，PL/pgSQL 分支也不是 portal 管理器的替换路径。

处理 {#response}

非替换 portal 路径报 ERROR 时，关闭旧 portal 或使用符合事务生命周期的新名称。WARNING 替换路径已经关闭旧 portal，应用仍应确认替换是预期行为。PL/pgSQL 应在重新打开前关闭命名游标，或使用不同变量/名称。只有 ERROR 路径需要通过回滚保存点或回滚事务恢复显式事务；重连不能替代查清连接池所有权。

消息变体 {#messages}

18.6 代表报文如下：

| 路径 | 严重性 | 主消息 | | --- | --- | --- | | CreatePortal(..., allowDup=false, ...) | ERROR | cursor "%s" already exists | | CreatePortal(..., allowDup=true, dupSilent=false) | WARNING | closing existing cursor "%s" | | 已找到 PL/pgSQL 命名游标 | ERROR | cursor "%s" already in use |

%s 为动态游标名称，本页不声称具体名称。

版本 {#versions}

目录范围从 7.4 到 18.6、19beta3，不是精确的功能引入判断。选定的是 18.6 固定 portal 管理器和 PL/pgSQL 源码路径，未运行数据库。

来源 {#sources}

src.errcodes.42P03.18.6 — src/backend/utils/errcodes.txt line 378，固定于 724edf9bde9d356724ad384a2e196edc3c9f80f7；SHA-256 6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba（源码）。
src.call.42P03.800a8278cf453417f5af6d6e — src/backend/utils/mmgr/portalmem.c lines 185-187，固定于 724edf9bde9d356724ad384a2e196edc3c9f80f7；SHA-256 8e29a302a7837316765acc798f9ff6eb22a330e8098a02794cd4d683601d3b04（源码）。
src.call.42P03.208bdd3b576b5021fb35916d — src/backend/utils/mmgr/portalmem.c lines 189-192，固定于 724edf9bde9d356724ad384a2e196edc3c9f80f7；SHA-256 8e29a302a7837316765acc798f9ff6eb22a330e8098a02794cd4d683601d3b04（源码）。
src.call.42P03.06c0580b43488eece2de1973 — src/pl/plpgsql/src/pl_exec.c lines 2895-2897，固定于 724edf9bde9d356724ad384a2e196edc3c9f80f7；SHA-256 0df3c70a6bccf6dddf443fb99e152a16a67009827c44a820597e98e585cb8b20（源码）。
src.calls.REL_18_6.42P03 — 固定本地核心调用扫描；SHA-256 9ee8a0e81d8f0825c5c1ae45583439859a26e602bdd4ce2f2a62aa278867ccbf。
作者证据 — 记录源码断言、消息角色和运行边界。

比较版本

SQLSTATE 证据与已记录的运行版本

claims · identity.class-and-condition

{
  "claim_id": "identity.class-and-condition",
  "limits": "Identity does not enumerate all source branches or client failures.",
  "method": "Read fixed REL_18_6 errcodes.txt and locked facts.",
  "position": 0,
  "runtime": [],
  "sources": [
    "src.errcodes.42P03.18.6"
  ],
  "statement": "42P03 is the duplicate_cursor condition in Class 42."
}

claims · mechanism.selected-source-path

{
  "claim_id": "mechanism.selected-source-path",
  "limits": "Representative confirmed core paths only; not exhaustive historical or extension coverage.",
  "method": "Read complete resolved REL_18_6 report groups and message roles.",
  "position": 1,
  "runtime": [],
  "sources": [
    "src.call.42P03.800a8278cf453417f5af6d6e",
    "src.call.42P03.208bdd3b576b5021fb35916d",
    "src.call.42P03.06c0580b43488eece2de1973"
  ],
  "statement": "CreatePortal(name, allowDup, dupSilent) reports ERROR `cursor \"%s\" already exists` when allowDup is false, can report WARNING `closing existing cursor \"%s\"` before dropping a duplicate when allowDup is true and dupSilent is false, and PL/pgSQL separately reports ERROR `cursor \"%s\" already in use` when SPI_cursor_find finds an active named cursor."
}

claims · versions.catalogue-boundary

{
  "claim_id": "versions.catalogue-boundary",
  "limits": "First observed release is a lower bound, not precise behavioral introduction.",
  "method": "Read locked catalogue facts and definition snapshots.",
  "position": 2,
  "runtime": [],
  "sources": [
    "src.errcodes.42P03.18.6"
  ],
  "statement": "From 7.4 through 18.6 and 19beta3; the selected portal-manager and PL/pgSQL branches are fixed 18.6 source paths and runtime was not run."
}

messages · message.variant-1

{
  "limits": "Placeholders remain dynamic source fields; no concrete runtime value is claimed.",
  "message_id": "message.variant-1",
  "path": "",
  "position": 0,
  "raw": {
    "detail_templates": [],
    "hint_templates": [],
    "id": "message.variant-1",
    "limits": "Placeholders remain dynamic source fields; no concrete runtime value is claimed.",
    "primary_template": "cursor \"%s\" already exists",
    "roles": [
      {
        "role": "errmsg",
        "template": "cursor \"%s\" already exists"
      }
    ],
    "severity_source": "explicit ERROR",
    "sources": [
      "src.call.42P03.800a8278cf453417f5af6d6e"
    ],
    "sqlstate": "42P03"
  },
  "severity": "explicit ERROR",
  "sources": [
    "src.call.42P03.800a8278cf453417f5af6d6e"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "cursor \" \" already exists",
      "position": 0,
      "role": "",
      "template": "cursor \"%s\" already exists"
    }
  ]
}

messages · message.variant-2

{
  "limits": "Placeholders remain dynamic source fields; no concrete runtime value is claimed.",
  "message_id": "message.variant-2",
  "path": "",
  "position": 1,
  "raw": {
    "detail_templates": [],
    "hint_templates": [],
    "id": "message.variant-2",
    "limits": "Placeholders remain dynamic source fields; no concrete runtime value is claimed.",
    "primary_template": "closing existing cursor \"%s\"",
    "roles": [
      {
        "role": "errmsg",
        "template": "closing existing cursor \"%s\""
      }
    ],
    "severity_source": "explicit WARNING",
    "sources": [
      "src.call.42P03.208bdd3b576b5021fb35916d"
    ],
    "sqlstate": "42P03"
  },
  "severity": "explicit WARNING",
  "sources": [
    "src.call.42P03.208bdd3b576b5021fb35916d"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "closing existing cursor \" \"",
      "position": 0,
      "role": "",
      "template": "closing existing cursor \"%s\""
    }
  ]
}

messages · message.variant-3

{
  "limits": "Placeholders remain dynamic source fields; no concrete runtime value is claimed.",
  "message_id": "message.variant-3",
  "path": "",
  "position": 2,
  "raw": {
    "detail_templates": [],
    "hint_templates": [],
    "id": "message.variant-3",
    "limits": "Placeholders remain dynamic source fields; no concrete runtime value is claimed.",
    "primary_template": "cursor \"%s\" already in use",
    "roles": [
      {
        "role": "errmsg",
        "template": "cursor \"%s\" already in use"
      }
    ],
    "severity_source": "explicit ERROR",
    "sources": [
      "src.call.42P03.06c0580b43488eece2de1973"
    ],
    "sqlstate": "42P03"
  },
  "severity": "explicit ERROR",
  "sources": [
    "src.call.42P03.06c0580b43488eece2de1973"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "cursor \" \" already in use",
      "position": 0,
      "role": "",
      "template": "cursor \"%s\" already in use"
    }
  ]
}

sources · src.errcodes.42P03.18.6

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "line 378",
  "path": "src/backend/utils/errcodes.txt",
  "position": 0,
  "sha256": "6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba",
  "source_id": "src.errcodes.42P03.18.6",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/errcodes.txt#L378"
}

sources · src.call.42P03.800a8278cf453417f5af6d6e

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "lines 185-187",
  "path": "src/backend/utils/mmgr/portalmem.c",
  "position": 1,
  "sha256": "8e29a302a7837316765acc798f9ff6eb22a330e8098a02794cd4d683601d3b04",
  "source_id": "src.call.42P03.800a8278cf453417f5af6d6e",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/mmgr/portalmem.c#L185-L187"
}

sources · src.call.42P03.208bdd3b576b5021fb35916d

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "lines 189-192",
  "path": "src/backend/utils/mmgr/portalmem.c",
  "position": 2,
  "sha256": "8e29a302a7837316765acc798f9ff6eb22a330e8098a02794cd4d683601d3b04",
  "source_id": "src.call.42P03.208bdd3b576b5021fb35916d",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/mmgr/portalmem.c#L189-L192"
}

sources · src.call.42P03.06c0580b43488eece2de1973

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "lines 2895-2897",
  "path": "src/pl/plpgsql/src/pl_exec.c",
  "position": 3,
  "sha256": "0df3c70a6bccf6dddf443fb99e152a16a67009827c44a820597e98e585cb8b20",
  "source_id": "src.call.42P03.06c0580b43488eece2de1973",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/pl/plpgsql/src/pl_exec.c#L2895-L2897"
}

sources · src.calls.REL_18_6.42P03

{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "",
  "path": "raw/calls/REL_18_6.jsonl",
  "position": 4,
  "sha256": "9ee8a0e81d8f0825c5c1ae45583439859a26e602bdd4ce2f2a62aa278867ccbf",
  "source_id": "src.calls.REL_18_6.42P03",
  "tag": "",
  "url": ""
}

来源引用

原始手册引用

完整定义与证据 JSON

定义来源

center · PostgreSQL 18 · english-manuals:d27355120217f732026b1e5ecc24092c4ae150ad963e5e9c2bd50b97943bd1f3

正文语言: zh-Hans · english-manuals:d27355120217f732026b1e5ecc24092c4ae150ad963e5e9c2bd50b97943bd1f3

42P03 — 重复游标

版本定义 PG 18

42P03 — 重复游标

速览 {#at-a-glance}

含义 {#meaning}

诊断 {#diagnosis}

处理 {#response}

消息变体 {#messages}

版本 {#versions}

相关 {#related}

来源 {#sources}

比较版本

SQLSTATE 证据与已记录的运行版本

来源引用