#foreignKey

ORA-46010: The colValue of foreignKey of inheritedFrom “string” is too long.

文档解释ORA-46010:ThecolValueofforeignKeyofinheritedFrom“string”istoolong.Cause:ThespecifiedlengthforthecolValueelementoftheforeignKeyelementoftheinheri...

ORA-46016: Number of columns of foreignKey does not match primaryKey.

文档解释ORA-46016:NumberofcolumnsofforeignKeydoesnotmatchprimaryKey.Cause:ThenumberofcolumnelementswithintheforeignKeyelementdidnotmatchthenumberofcolumnelementswit...

ORA-46007: No colName foreignKey for inheritedFrom element “string”.

文档解释ORA-46007:NocolNameforeignKeyforinheritedFromelement“string”.Cause:NocolNameforeignKeywasspecifiedforaninheritedFromelementintheDataSecuritypoli...

ORM之ForeignKey操作

数据量比较大,不会使用FK,允许出现数据冗余。对象查找(跨表)语法:对象.关联字段.字段示例:book_obj=models.Book.objects.first()#第一本书对象print(book_obj.publisher)#得到这本书关联的出版社对象print(book_obj.publisher.name)#...
代码星球 ·2020-12-29

laravel Call to undefined method 1IlluminateDatabaseQueryBuilder::getForeignKeyName() or 1IlluminateDatabaseQueryBuilder::getQualifiedForeignKeyName()

vendor/laravel/framework/src/Illuminate/Database/Eloquent/Relations/BelongsTo.php添加!!!!!!!publicfunctiongetForeignKeyName(){$segments=explode('.',$this->getQ...

Django:model中的ForeignKey理解

有两个数据模型栏目模型和文章模型ArticleColumn和ArticlePostArticleColumn:classArticleColumn(models.Model):#用户与栏目是“一对多”关系,所以用ForeignKey,一个用户可以设置多个栏目,此处的user字段对应实际表中的us...