How can we change the name and data type of a column of a
table?
Answer Posted / nithya
To change the name of the column:
ALTER TABLE TABLENAME RENAME COLUMN OLD_COLUMN_NAME TO
NEW_COLUMN_NAME;
eg: alter table employee rename column emp_name to ename;
To change the datatype of a column:
ALTER TABLE TABLENAME MODIGY COLUMN_NAME NEW_DATA_TYPE;
eg: alter table employee modify ename varchar(50);
NOTE: u cannot modify column of a datatype from larger value
to smaller value.U can do it only if there is no data in ur
column.
eg: alter table employ_detail modify emp_addr varchar(5);
ORA-01441: cannot decrease column length because some value
is too big
alter table employ_detail modify emp_id number(2)
ORA-01440: column to be modified must be empty to decrease
precision or scale
| Is This Answer Correct ? | 9 Yes | 4 No |
Post New Answer View All Answers
What is an example of a delimiter?
How do you know the version of your mysql server?
How many mysql connections can handle?
How you will Show unique records.
Is mysql free for commercial use?
How can you count the total number of records of any table?
Does facebook still use mysql?
How do I change mysql password?
what is database black box testing? : Mysql dba
What are queries used for?
What is regexp?
What is the maximum no of columns a table can have?
How do I install mysql?
What are the different mysql database engines?
What is latest version of mysql?