sql - 内连接上的多个主键
IneedtocountallrowswithdistinctiveItemID:swiththehighestRevisionIDontheitemwiththatItemID.Here'smycode(relevantparts):我需要计算具有独特ItemID的所有行:具有该ItemID的项目...
SQLAlchemy将多个外键在一个映射类中转换为相同的主键
Amtryingtosetupapostgresqltablethathastwoforeignkeysthatpointtothesameprimarykeyinanothertable.我试图设置一个postgresql表,它有两个指向另一个表中相同主键的外键。WhenIrunthescript...
phpmyadmin不允许一个表创建多个主键的解决办法
在phpmyadmin中执行建表语句CREATETABLE`user3`(`id`int(11)NOTNULLAUTO_INCREMENT,`username`varchar(255)NOTNULL,`nack`varchar(255)DEFAULTNULL,PRIMARYKEY(`username...
数据库多个主键(联合主键)
创建某表,需要两个主键(INST_ID,INST_RESP_CODE)CREATETABLECODE_CONVERTER_20170806(INST_IDCHARACTER(4)NOTNULL,INST_RESP_CODEVARCHAR(32)NOTNULL,TRANS_CODEVARCHAR(8)...
一个外键引用多个主键
Ihavetwotableswithsingleprimarykeycolumnsineachofthosetwotablesandanothertable(table3)whichhasaforeignkeythatrefersbothofthoseaboveprimarykey'scolumns...
SQL多个外键作为主键
IfIdeclarethetablebelowdoesitimplicitlyimplythatboththeforeignkeysmakeauniqueprimarykeyordoIneedtodosomethingmoretomakebothattributesasaprimarykey?如果我...
多个模型 - 一个通用主键(Django)
Iwishanicedaytoeveryone.AsI'vementionedintitle,IwouldliketojoinmultiplemodelsandidentifyoneofthemwithoneglobalID,sotheIDwoulddeterminewhichmodelitisan...
在实体框架中设置多个外键作为主键
I'musingentityframeworktomanagemysql-server-cedatabase.iwantmytable'sprimarykeytobeconsistedofseveralforeignkeystoothertables.iexpectedsomethingliketh...