Altering the data type of a column
Changing the data type of a column after it is defined or added to a table using ALTER TABLE.
Using ALTER TABLE, you can change the data type of a column after it is defined or added to a table.
Procedure
Change the
favorite_color
column to store as
text
instead of varchar
by changing the
data type of the column.
ALTER TABLE cycling.cyclist_alt_stats ADD favorite_color varchar;
ALTER TABLE cycling.cyclist_alt_stats ALTER favorite_color TYPE text;
Only newly inserted values will be created with the new type. However,
the data type before must be compatible with the
new data type specified.