试题详情
- 单项选择题 The EMPLOYEES table has these columns: LAST_NAME VARCHAR2(35) SALARY NUMBER(8,2) HIRE_DATE DATE Management wants to add a default value to the SALARY column. You plan to alter the table by using this SQL statement: ALTER TABLE EMPLOYEES MODIFY (SALARY DEFAULT 5000); Which is true about your ALTER statement?（）
A、Column definitions cannot be altered to add DEFAULT values.
B、A change to the DEFAULT value affects only subsequent insertions to the table.
C、Column definitions cannot be altered to add DEFAULT values for columns with a NUMBER data type.
D、All the rows that have a NULL value for the SALARY column will be updated with the value 5000.
- B
关注下方微信公众号，在线模考后查看
热门试题
- You have not configu
- Which statemen
- Your database is in
- To implement Automa
- Given： Which t
- DRAGDROPClicktheTask
- What is
- Which statement is t
- Which initiali
- You are wo
- ViewtheExhibitforthe
- You are
- （）像表一样由列组成，其查询方式与表相同
- Which two̳
- 初始化参数（）指定了实例启动时希望创建的
- You are
- You have
- Examinethefollowings
- Globalization suppor
- 下列对于惟一码约束，说法错误的是（）。