Using alter command!!
www.w3schools.com/.../sql_foreignkey.asp

 table1 

 table 2

based on the above two tables tabel1 & table 2 ,I want claim id is foreign key in the table 2 ? what is the syntax ?

Did you check the link I provided in the above comment?

yea I checked bro ,& use different types of commends but not get my problem, error coming

when i use

ALTER TABLE LMS_Aprrovals
ADD FOREIGN KEY (Claim ID) REFERENCES lmscustomerdetails(id);

this error gets

Error

SQL query: Copy

ALTER TABLE LMS_Aprrovals
ADD FOREIGN KEY (Claim ID) REFERENCES lmscustomerdetails(id);

MySQL said: 

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'ID) REFERENCES lmscustomerdetails(id)' at line 2

when i use

ALTER TABLE LMS_Aprrovals
ADD FOREIGN KEY (Claim ID) REFERENCES lmscustomerdetails(id);

this error gets

Error

SQL query: Copy

ALTER TABLE LMS_Aprrovals
ADD FOREIGN KEY (Claim ID) REFERENCES lmscustomerdetails(id);

MySQL said: 

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'ID) REFERENCES lmscustomerdetails(id)' at line 2

this is third try

Error

SQL query: Copy

ALTER TABLE LMS_Aprrovals
ADD CONSTRAINT my_fk_type,
ADD FOREIGN KEY (Claim ID) REFERENCES lmscustomerdetails(id);

MySQL said: 

#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near '
ADD FOREIGN KEY (Claim ID) REFERENCES lmscustomerdetails(id)' at line 2

1 
2 

that's ok bro I got it & one more thing how to delete a unnecessary or useless table (entire table)in mariaDB