42P06 — 重复模式

要创建的模式名在当前数据库中已存在。

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_schema
lang: en
sqlstate: 42P06

版本定义 PG 18

42P06 — 重复模式

速览 {#at-a-glance}

42P06（duplicate_schema）是模式定义冲突。普通 CREATE 报 ERROR；IF NOT EXISTS 可发 NOTICE 并继续，但条件路径只是跳过创建，不会协调已有模式。

含义 {#meaning}

NamespaceCreate 发现 pg_namespace 中已有同名行时报告 ERROR schema "%s" already exists。CREATE SCHEMA IF NOT EXISTS 检查同一命名空间后，在创建前报告 NOTICE schema "%s" already exists, skipping。两条报文都指向模式本身，不是其中的关系；固定命令路径先做创建权限检查，NOTICE 不表示已经比较了所有者或定义。

诊断 {#diagnosis}

确认目标数据库和模式，检查 pg_namespace.nspname、所有者/ACL、内容和准确迁移语句。保留严重性：NOTICE 是条件行为并让命令继续，普通 CREATE 的 ERROR 会使显式事务失败。不能从 NOTICE 推出已有模式的所有者、授权、扩展、表或迁移版本符合要求。

处理 {#response}

仅在所有权、权限和内容符合业务契约时复用。IF NOT EXISTS 不验证也不协调这些属性，需要时应追加明确的所有权、授权和迁移检查。不要删除模式来通过迁移。普通 CREATE 在显式事务中报 ERROR 后，应回滚到合适保存点或回滚事务再继续。

消息变体 {#messages}

选定变体是 schema "%s" already exists（明确 ERROR）和 schema "%s" already exists, skipping（明确 NOTICE）。%s 是动态模式名；两条报文都不保证已有模式的所有者或定义。

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 ERROR 和 NOTICE 源码路径，未运行数据库。

来源 {#sources}

src.errcodes.42P06.18.6 — src/backend/utils/errcodes.txt line 382，固定于 724edf9bde9d356724ad384a2e196edc3c9f80f7；SHA-256 6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba（源码）。
src.call.42P06.4d5505b63e38ef1b25836623 — src/backend/catalog/pg_namespace.c lines 62-64，固定于 724edf9bde9d356724ad384a2e196edc3c9f80f7；SHA-256 89675ba1bb9c531ab4f43db8a6f7cac00956561b342e42ea6eaae6b8d0b50d78（源码）。
src.call.42P06.373538bec86ad8eedfce8d7a — src/backend/commands/schemacmds.c lines 132-135，固定于 724edf9bde9d356724ad384a2e196edc3c9f80f7；SHA-256 5fd5f43dce5f36f06ed390014c06f244564072227d25a22735f594d2170626b1（源码）。
src.calls.REL_18_6.42P06 — 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.42P06.18.6"
  ],
  "statement": "42P06 is the duplicate_schema 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.42P06.4d5505b63e38ef1b25836623",
    "src.call.42P06.373538bec86ad8eedfce8d7a"
  ],
  "statement": "NamespaceCreate reports ERROR `schema \"%s\" already exists` when pg_namespace already contains the name. CREATE SCHEMA IF NOT EXISTS checks the namespace and reports NOTICE `schema \"%s\" already exists, skipping` before creation; the conditional path does not compare or reconcile owner, ACL, or contents."
}

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.42P06.18.6"
  ],
  "statement": "From 7.4 through 18.6 and 19beta3; this catalogue range is not a precise introduction claim. The selected ERROR and NOTICE 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": "schema \"%s\" already exists",
    "roles": [
      {
        "role": "errmsg",
        "template": "schema \"%s\" already exists"
      }
    ],
    "severity_source": "explicit ERROR",
    "sources": [
      "src.call.42P06.4d5505b63e38ef1b25836623"
    ],
    "sqlstate": "42P06"
  },
  "severity": "explicit ERROR",
  "sources": [
    "src.call.42P06.4d5505b63e38ef1b25836623"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "schema \" \" already exists",
      "position": 0,
      "role": "",
      "template": "schema \"%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": "schema \"%s\" already exists, skipping",
    "roles": [
      {
        "role": "errmsg",
        "template": "schema \"%s\" already exists, skipping"
      }
    ],
    "severity_source": "explicit NOTICE",
    "sources": [
      "src.call.42P06.373538bec86ad8eedfce8d7a"
    ],
    "sqlstate": "42P06"
  },
  "severity": "explicit NOTICE",
  "sources": [
    "src.call.42P06.373538bec86ad8eedfce8d7a"
  ],
  "templates": [
    {
      "kind": "primary",
      "literal": "schema \" \" already exists, skipping",
      "position": 0,
      "role": "",
      "template": "schema \"%s\" already exists, skipping"
    }
  ]
}

sources · src.errcodes.42P06.18.6

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "line 382",
  "path": "src/backend/utils/errcodes.txt",
  "position": 0,
  "sha256": "6e8de346643ba84aa3c9c6a73360acfc7b2dfb89162c06c08ce9bf5bcd5bbcba",
  "source_id": "src.errcodes.42P06.18.6",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/errcodes.txt#L382"
}

sources · src.call.42P06.4d5505b63e38ef1b25836623

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "lines 62-64",
  "path": "src/backend/catalog/pg_namespace.c",
  "position": 1,
  "sha256": "89675ba1bb9c531ab4f43db8a6f7cac00956561b342e42ea6eaae6b8d0b50d78",
  "source_id": "src.call.42P06.4d5505b63e38ef1b25836623",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/catalog/pg_namespace.c#L62-L64"
}

sources · src.call.42P06.373538bec86ad8eedfce8d7a

{
  "commit": "724edf9bde9d356724ad384a2e196edc3c9f80f7",
  "docs_url": "",
  "kind": "upstream_source",
  "location": "lines 132-135",
  "path": "src/backend/commands/schemacmds.c",
  "position": 2,
  "sha256": "5fd5f43dce5f36f06ed390014c06f244564072227d25a22735f594d2170626b1",
  "source_id": "src.call.42P06.373538bec86ad8eedfce8d7a",
  "tag": "REL_18_6",
  "url": "https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/commands/schemacmds.c#L132-L135"
}

sources · src.calls.REL_18_6.42P06

{
  "commit": "",
  "docs_url": "",
  "kind": "local_artifact",
  "location": "",
  "path": "raw/calls/REL_18_6.jsonl",
  "position": 3,
  "sha256": "9ee8a0e81d8f0825c5c1ae45583439859a26e602bdd4ce2f2a62aa278867ccbf",
  "source_id": "src.calls.REL_18_6.42P06",
  "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:867192f9d416b05d071f1243acf544501328144e33f33798fc55a36bf0af5287

正文语言: zh-Hans · english-manuals:867192f9d416b05d071f1243acf544501328144e33f33798fc55a36bf0af5287

42P06 — 重复模式

版本定义 PG 18

42P06 — 重复模式

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