minte9
SoftwareDevelopment / MYSQL





Add column 

 
ALTER TABLE mytable ADD myemail varchar(30);
ALTER TABLE mytable ADD COLUMN myaddress varchar(30);

Add column (after / before) 

 
ALTER TABLE mytable ADD COLUMN myphone varchar(30) AFTER myname;
ALTER TABLE mytable ADD COLUMN id2 int(11) FIRST;

Alter column 

 
ALTER TABLE mytable CHANGE COLUMN myname myname_new  int(11);

Drop column 

 
ALTER TABLE mytable DROP  COLUMN id2;






Questions and answers:
Clink on Option to Answer




1. Add a new field

  • a) ALTER ... ADD catg ...
  • b) ALTER ... ADD FIELD catg ...

2. How do you ADD column after another?

  • a) ALTER ... ADD COLUMN AFTER(name) phone ...

3. How do you update column name?

  • a) ALTER ... UPDATE COLUMN catg catg_new ...
  • b) ALTER ... CHANGE COLUMN catg catg_new ...

4. How do you delete column?

  • a) ALTER ... DROP COLUMN catg
  • b) ALTER ... DELETE catg


References: