【发布时间】：2021-03-12 09:58:39
【问题描述】：
我有以下情况。
export default class BucketEntity extends Entity {
@Column({
type: "enum",
enum: BucketType,
default: BucketType.Notes,
})
type: BucketType;
@Column()
title: string;
@OneToOne(() => BucketEntity, {
nullable: true,
onDelete: "NO ACTION",
deferrable: "INITIALLY DEFERRED",
})
@JoinColumn()
prev: Promise<BucketEntity | null>;
@Column({ nullable: true })
prevId: number | null;
@OneToOne(() => BucketEntity, {
nullable: true,
onDelete: "NO ACTION",
deferrable: "INITIALLY DEFERRED",
})
@JoinColumn()
next: Promise<BucketEntity | null>;
@Column({ nullable: true })
nextId: number | null;
}
这是一个Bucket 实体，它与自身有两个一对一的关系。想想双向链表。每个Bucket 都有一个prev 和一个next 参考。这些关系具有deferrable: true 标志，这意味着我得到了一个可延迟的 FK 约束。
这是由该实体构建的实际表格：
Table "public.dashboardBuckets"
Column | Type | Collation | Nullable | Default
-----------+------------------------------+-----------+----------+------------------------------------------------
id | integer | | not null | nextval('"dashboardBuckets_id_seq"'::regclass)
createdAt | timestamp without time zone | | not null | now()
updatedAt | timestamp without time zone | | not null | now()
type | "dashboardBuckets_type_enum" | | not null | 'Notes'::"dashboardBuckets_type_enum"
title | character varying | | not null |
prevId | integer | | |
nextId | integer | | |
Indexes:
"PK_6823bada941d24553e040989058" PRIMARY KEY, btree (id)
"REL_9fc9b030d495660236b8d00074" UNIQUE CONSTRAINT, btree ("nextId")
"REL_ea16688a9b632de7758cf696b5" UNIQUE CONSTRAINT, btree ("prevId")
Foreign-key constraints:
"FK_9fc9b030d495660236b8d00074a" FOREIGN KEY ("nextId") REFERENCES "dashboardBuckets"(id) DEFERRABLE INITIALLY DEFERRED
"FK_ea16688a9b632de7758cf696b52" FOREIGN KEY ("prevId") REFERENCES "dashboardBuckets"(id) DEFERRABLE INITIALLY DEFERRED
Referenced by:
TABLE ""dashboardBuckets"" CONSTRAINT "FK_9fc9b030d495660236b8d00074a" FOREIGN KEY ("nextId") REFERENCES "dashboardBuckets"(id) DEFERRABLE INITIALLY DEFERRED
TABLE ""dashboardBuckets"" CONSTRAINT "FK_ea16688a9b632de7758cf696b52" FOREIGN KEY ("prevId") REFERENCES "dashboardBuckets"(id) DEFERRABLE INITIALLY DEFERRED
我在这样的事务中更新nextId/prevId 字段：
const qr = getConnection().createQueryRunner();
await qr.connect();
await qr.startTransaction();
await qr.query("SET CONSTRAINTS ALL DEFERRED;");
try {
// Update bucket prev/next refs ------------------------------------ //
// await getConnection().transaction(async (t) => {
let next, prev, oldPrev, oldNext;
if (prevId !== undefined && nextId !== undefined) {
const repo = qr.manager.getRepository(BucketEntity);
// olds
const oldPrevId = bucket.prevId;
const oldNextId = bucket.nextId;
oldPrev =
bucket.prevId === null
? null
: await repo.findOne(bucket.prevId, {
relations: ["prev", "next"],
});
oldNext =
bucket.nextId === null
? null
: await repo.findOne(bucket.nextId, {
relations: ["prev", "next"],
});
// update
bucket.prevId = prevId;
bucket.nextId = nextId;
if (prevId !== null) {
prev =
prevId === oldNextId
? oldNext
: await repo.findOne(prevId, {
relations: ["prev", "next"],
});
if (prev === undefined) throw new BucketDoesntExistError();
if (prev !== null) prev.nextId = bucket.id;
}
if (nextId !== null) {
next =
nextId === oldPrevId
? oldPrev
: await repo.findOne(nextId, {
relations: ["prev", "next"],
});
if (next === undefined) throw new BucketDoesntExistError();
if (next !== null) next.prevId = bucket.id;
}
// update oldPrev/oldNext
if (oldPrev) {
oldPrev.nextId = oldNextId;
}
if (oldNext) {
oldNext.prevId = oldPrevId;
}
}
// ----------------------------------------------------------------- //
if (oldNext) {
await qr.manager.update(
BucketEntity,
{ id: oldNext.id },
{ prevId: oldNext.prevId, nextId: oldNext.nextId }
);
}
if (oldPrev) {
await qr.manager.update(
BucketEntity,
{ id: oldPrev.id },
{ prevId: oldPrev.prevId, nextId: oldPrev.nextId }
);
}
if (next) {
await qr.manager.update(
BucketEntity,
{ id: next.id },
{ prevId: next.prevId, nextId: next.nextId }
);
}
if (prev) {
await qr.manager.update(
BucketEntity,
{ id: prev.id },
{ prevId: prev.prevId, nextId: prev.nextId }
);
}
await qr.manager.update(
BucketEntity,
{ id: bucket.id },
{ prevId: bucket.prevId, nextId: bucket.nextId }
);
await qr.commitTransaction();
} catch (error) {
console.log("------------------------------------- error", error);
await qr.rollbackTransaction();
} finally {
await qr.release();
}
我收到以下错误：
error QueryFailedError: duplicate key value violates unique constraint "REL_ea16688a9b632de7758cf696b5"
at new QueryFailedError (/Users/work/code/dashify-server/src/error/QueryFailedError.ts:9:9)
at Query.callback (/Users/work/code/dashify-server/src/driver/postgres/PostgresQueryRunner.ts:220:30)
at Query.handleError (/Users/work/code/dashify-server/node_modules/pg/lib/query.js:128:19)
at Client._handleErrorMessage (/Users/work/code/dashify-server/node_modules/pg/lib/client.js:335:17)
at Connection.emit (events.js:315:20)
at Connection.EventEmitter.emit (domain.js:483:12)
at /Users/work/code/dashify-server/node_modules/pg/lib/connection.js:115:12
at Parser.parse (/Users/work/code/dashify-server/node_modules/pg-protocol/src/parser.ts:102:9)
at Socket.<anonymous> (/Users/work/code/dashify-server/node_modules/pg-protocol/src/index.ts:7:48)
at Socket.emit (events.js:315:20) {
length: 237,
severity: 'ERROR',
code: '23505',
detail: 'Key ("prevId")=(1) already exists.',
hint: undefined,
position: undefined,
internalPosition: undefined,
internalQuery: undefined,
where: undefined,
schema: 'public',
table: 'dashboardBuckets',
column: undefined,
dataType: undefined,
constraint: 'REL_ea16688a9b632de7758cf696b5',
file: 'nbtinsert.c',
line: '656',
routine: '_bt_check_unique',
query: 'UPDATE "dashboardBuckets" SET "prevId"=$1, "nextId"=$2 WHERE id=$3;',
parameters: [ 1, null, 3 ]
}
这发生在具有延迟约束的事务中。难道不应该等到事务提交后再抛出错误，如果有任何重复？这发生在第一次更新查询之后。数据库是 postgresql。
关于我做错了什么有什么想法吗？
谢谢！
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标签： node.js postgresql typeorm