我正在使用rails 2项目,并在运行rake任务时遇到以下错误。有人可以帮助我解决可能导致这种情况的原因。
[root@localhost webapp]# rake db:migrate
(in /root/public/webapp)
== CreateWhereKeywords: migrating ============================================
-- create_table(:where_keywords)
NOTICE: CREATE TABLE will create implicit sequence "where_keywords_id_seq" for serial column "where_keywords.id"
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "where_keywords_pkey" for table "where_keywords"
-> 0.0838s
-- execute("alter table where_keywords add constraint where_keyword foreign key (where_location_id) references \n where_locations(id) on delete cascade")
rake aborted!
An error has occurred, this and all later migrations canceled:
PGError: ERROR: foreign key constraint "where_keyword" cannot be implemented
DETAIL: Key columns "where_location_id" and "id" are of incompatible types: character varying and integer.
: alter table where_keywords add constraint where_keyword foreign key (where_location_id) references
where_locations(id) on delete cascade
答案 0 :(得分:3)
错误信息非常清楚:
键列“where_location_id”和“id”属于不兼容的类型:字符变化和整数
当where_keywords.where_location_id
列需要varchar
时,您将integer
列创建为where_locations.id
列,以便它可以引用FK中的create_table :where_keywords do |t|
#...
t.string :where_location_id
#...
end
。您的迁移有类似的内容:
create_table :where_keywords do |t|
#...
t.integer :where_location_id
#...
end
应该更像这样:
{{1}}