Can a table have two foreign keys

Question

I have the following tables  Primary key in bold  Foreign key in Italic   Customer table   ID---Name---Balance---Account Name---Account Type   Account Category table   Account Type----Balance   Customer Detail table   Account Name---First Name----Last Name---Address   Can I have two foreign keys in the Customer table and how can I implement this in MySQL     Updated  I am developing a web based accounting system for a final project   Account Category  Account Type--------------Balance  Assets Liabilities Equity Expenses Income     Asset     Asset ID-----Asset Name----Balance----Account Type   Receivable   Receivable ID-----Receivable Name-------Address--------Tel-----Asset ID----Account Type   Receivable Account   Transaction ID----Description----Amount--- Balance----Receivable ID----Asset ID---Account Type   I drew the ER Entity relationship  diagram using a software and when I specify the relationship it automatically added the multiple foreign keys as shown above  Is the design not sound enough

User · Accepted Answer

Yes  MySQL allows this  You can have multiple foreign keys on the same table    Get more details here FOREIGN KEY Constraints

User · Answer

CREATE TABLE User   user id INT NOT NULL AUTO INCREMENT  userName VARCHAR 100  NOT NULL  password VARCHAR 255  NOT NULL  email VARCHAR 255  NOT NULL  userImage  LONGBLOB NOT NULL   Favorite VARCHAR 255  NOT NULL  PRIMARY KEY  user id       and   CREATE TABLE Event       EventID INT NOT NULL AUTO INCREMENT       PRIMARY KEY  EventID       EventName VARCHAR 100  NOT NULL      EventLocation VARCHAR 100  NOT NULL      EventPriceRange VARCHAR 100  NOT NULL      EventDate Date NOT NULL      EventTime Time NOT NULL      EventDescription VARCHAR 255  NOT NULL      EventCategory VARCHAR 255  NOT NULL      EventImage  LONGBLOB NOT NULL           index EventID       FOREIGN KEY  EventID  REFERENCES User user id

User · Answer

The foreign keys in your schema  on Account Name and Account Type  do not require any special treatment or syntax  Just declare two separate foreign keys on the Customer table  They certainly don t constitute a composite key in any meaningful sense of the word   There are numerous other problems with this schema  but I ll just point out that it isn t generally a good idea to build a primary key out of multiple unique columns  or columns in which one is functionally dependent on another  It appears that at least one of these cases applies to the ID and Name columns in the Customer table  This allows you to create two rows with the same ID  different name   which I m guessing you don t want to allow

User · Answer

create table Table1     id varchar 2     name varchar 2     PRIMARY KEY  id      Create table Table1 Addr     addid varchar 2     Address varchar 2     PRIMARY KEY  addid     Create table Table1 sal     salid varchar 2   enter code here    addid varchar 2     id varchar 2     PRIMARY KEY  salid     index addid     index id     FOREIGN KEY  addid  REFERENCES Table1 Addr addid     FOREIGN KEY  id  REFERENCES Table1 id

User · Answer

Yes  a table have one or many foreign keys and each foreign keys hava a different parent table

[mysql] Can a table have two foreign keys?

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