foreign keys - MySQL how to make a column of child table point to the parent table? -


i've started mysql database , confused foreign key do.

suppose have parent table (teacher) of , taxno primary key;

taxno   tfname   tlname   tgender   tquali    thours        1111    toh       jim       m       honours    120

and childtable (teacsub);

taxno   tfname   tlname   tgender   tquali    thours  subtitle subtype

how make if, example, input teacsub is

 taxno   tfname   tlname   tgender   tquali    thours  subtitle   subtype   1111   dddd       dddd      f       weqwe      100     history     3

it prompmt me input teacsub wrong?

i have created foreign key taxno applies taxno.

the beauty of relational db constructed tables, not need repeat information have been doing.

if teacher table contains information persons name, gender etc, not need duplicate information anywhere else.

for example, if teacsub table teacsub(taxno, subtitle, subtype), can 'full' information joining 2 tables query this:

select *   teacher     inner join teacsub       on teacher.taxno = teacsub.taxno

and happily go off , pull rows both tables share common taxno


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