alter table 열 추가
ALTER TABLE table_name
ADD column_name datatype;
sql alter table 열 추가 존재하는 경우
IF NOT EXISTS (
SELECT
*
FROM
INFORMATION_SCHEMA.COLUMNS
WHERE
TABLE_NAME = 'table_name' AND COLUMN_NAME = 'col_name')
BEGIN
ALTER TABLE table_name
ADD col_name data_type NULL
END;