how to make the newly added column as foreign keyto its parent table in mysql?

[suma2006]

Hi All,

I have one table for that i want to add one more column and making that column as foreign key to some other table.How can i do that?can any one give the syntax?

here i know the syntax for adding a column:

ALTER TABLE <table_name> ADD COLUMN <column_name> <datatype>

Regards,
Suma

[amitpatel66]

Hi All,

I have one table for that i want to add one more column and making that column as foreign key to some other table.How can i do that?can any one give the syntax?

here i know the syntax for adding a column:

ALTER TABLE <table_name> ADD COLUMN <column_name> <datatype>
 

Regards,
Suma

After Adding a column, use the below syntax to add foreign key to the column of a particular table:

ALTER TABLE <table_name> ADD FOREIGN KEY (<column_name>) REFERENCES <table_name>(<column_name>)

The second column_name in the above query syntax should be a PRIMARY KEY

[suma2006]

Thank you very much! i am new to DB.

How can i add primary key constraint to the existing column?

Regards,
suma

[amitpatel66]

Thank you very much! i am new to DB.

How can i add primary key constraint to the existing column?

Regards,
suma

ALTER TABLE <table_name> ADD PRIMARY KEY (<column_name>)

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