change a column sql code example

Example 1: alter table modify column

-- ORACLE 18c
ALTER TABLE table_name 
MODIFY column_name datatype;

-- Example
ALTER TABLE product
MODIFY description VARCHAR2(500 char);

Example 2: alter table query sql server change column

ALTER TABLE table_name
  ALTER COLUMN column_name column_type;

Example 3: sql change column in existing table

'This adds 'NOT NULL' to excisting column counting in the table mytable'
ALTER TABLE mytable ALTER COLUMN counting INT NOT NULL;

Example 4: alter table query sql server change column

ALTER TABLE table_name
  DROP COLUMN column_name;