單項選擇題

TEAMS表包含以下各列:
TEAM_ID NUMBER(4)
Primary Key TEAM_NAMEVARCHAR2(20)
MGR_ID NUMBER(9)
TEAMS表當前是空表。您需要允許用戶在經(jīng)理標識值中包含文本字符。應使用以下哪條語句來執(zhí)行此任務()

A.ALTER teams MODIFY(mgr_id VARCHAR2(15))
B.ALTERTABLE teams MODIFY(mgr_id VARCHAR2(15))
C.ALTERTABLE teams REPLACE(mgr_id VARCHAR2(15))
D.ALTER teams TABLEMODIFYCOLUMN(mgr_id VARCHAR2(15))

微信掃碼免費搜題