MySQL Add field and delete field

How should MySQL add fields be implemented? This is a lot of new contacts MySQL database has been mentioned, the following is to introduce you to MySQL add fields and delete the field method, I hope you can be enlightened.

MySQL add field:

1. ALTER TABLE ' User_movement_log '
2. Add column Gatewayid int not null default 0 after ' RegionID ' (which field is added later)

To delete a field:

1. ALTER TABLE ' user_movement_log ' drop column Gatewayid

To adjust the order of fields:

2. ALTER TABLE ' user_movement_log ' Gatewayid ' gatewayid ' int not null default 0 after RegionID
6. Primary key
10. ALTER TABLE tabelname add new_field_id int (5) unsigned default 0 NOT NULL auto_increment, add primary key (NEW_FIELD_ID); /Add a new column
14. ALTER TABLE T2 add d timestamp;
16. ALTER TABLE infos add ex tinyint NOT null default ' 0 ';//Delete Column
20. ALTER TABLE T2 drop column c;//rename columns
24. ALTER TABLE T1 change a b integer;
26. Changing the type of a column
30. ALTER TABLE T1 change b b bigint not null;
32. ALTER TABLE infos change list list tinyint not null default ' 0 ';
34. Renaming a table
38. ALTER TABLE T1 rename T2; add index
42. MySQL> ALTER TABLE tablename change depno depno int (5) is not null;
44. MySQL> ALTER TABLE tablename ADD index index name (field name 1[, field Name 2 ...]);
46. MySQL> ALTER TABLE tablename add index Emp_name (name);
50. MySQL> ALTER TABLE tablename add PRIMARY key (ID); add unique constraint index
54. MySQL> ALTER TABLE tablename add unique emp_name2 (cardnumber); Delete an index
58. MySQL>alter table tablename DROP index emp_name; Modify table:

Add Field:

1. mysql> alter table table_name add  field_name field_type; Modify the original field name and type:  
2.  
3. mysql > alter table table_name change old_field_name new_field_ name field_type; Delete field:  
4.  
5. mysql>  alter table table_name drop field_name;