找考题网-背景图
单项选择题

Review the definition of the phone_list view.
CHEATE OR REPLACE ALGORITHM=MERGE DEFINER= 'root'@localhost' SQL SECURITY DEFINER VIEW 'phone_list' AS SELECT
e . id as id 'e . first_name AS 'first_name' 'e . last_name AS 'last_name' 'coalesce ( ph1.phone_no, ' – ') AS 'office_no' 'coalesce (ph2 .phone_no, ' – ') AS 'cell_no' FROM employees e LEFT JOIN employee_phone ph1 ON ph1.emp_id = e.id AND ph1.type = 'office' LEFT JOIN employee_phone ph2 ON ph2 .emp_id = e.id AND ph2 .type = 'mobile'
The tables employees and employee_phone are InnoDB tables;
all columns are used in this view. The contents of the phone_list view are as follows: Mysql> select * from phone_list; 1 row in set (0.00 sec)
Which method can you use to change the cell_no value to '555-8888' for John Doe?()

A.INSERT INTO employee_phone (emp_id, phone_no, type) VALUES (1, '555-8888','mobile')
B.UPDATE phone_list SET cell_name '555-8888' WHERE first_name= 'John' and last_name= 'Doe'
C.DELETE FROM phone_list WHERE first_name= 'John' and last_name= 'Doe'; INSERT INTO phone_list (first_name, last_name, office_no, cell_no) VALUES ('John' , 'Doe' , 'x1234' , '555-8888)
D.UPDATE employee_phone SET phone_no= '555-8888' where emp_id=1

热门试题

单项选择题You have enabled the Slow Query Log for a short period. When you process the Slow Query Log, you receive the following snip of output: Count: 100 Time=0 .22a (22s) Lock=0.00s (0s) Rows=0.0 (0), root[root] @localhost CREATE TABLE t1 (id serial,id0 varchar(N) unique key,intcaoll INT (N) ,intco12 INT(N) ,intco13 INT(N) ,intco14 INT(N) ,intco15 INT(N) ,charcol1 VARVHAR(N) ,charcol2 VARCHAR(N) charcol3 VARCHAR (N) ,charcol4 VARVHAR(N) ,charcol5 VARCHAR(N) charcol6 VARCHAR (N) ,charcol7 VARVHAR(N) ,charcol8 VARCHAR(N) charcol9 VARCHAR (N) .charcol 10 VACHAR (N) ) Count: 64000 Time-0.02s (1213s) Lock=0.00s (6s) Rows=1.0 (64000), root [root]@ localhost SELECT intocl1, intco12, intco13, intco14, intco15, intco16,intco17, intco18 ,intcol9, intcol10, charcol1, charcol2, charcol3, charcol4, charcol5, charcol6 ,charcol7, charcol8, charcol9, charcol10 FROM t1 WHERE id = s Count: 1 Time=0.02s (0s) Lock=0.00s (0s) Rows=1.0 (1) agent [agent] @localhost SELECT Select_priv, Repl_client_priv, Show_db_priv, Super_priv, Process_priv FROM mysql.user WHERE CONCAT (user, s, host) = CURRENT_USER () Count: 48000 Time=0.02s (778s) Lock=0.00 (3s) Rows=1.0 (48000), root[root]@localhost SELECT intocl1,intcol2,intcol3, intcol4, intcol5, charcol1, charcol2, charcol3 ,charcol4, charcol5, charcol6, charcol7, charcol8, charcol9, charcol10 FROM t1 WHERE id = s You want to tune the query such that it provides the greatest overall time savings. Which query will accomplish this?()

A.CHEATE TABLE 't1' (id serial, id0 varchar (N) unique key, intcol1 INT (N) ,intcol2 INT (N), intcol3 INT(N) ,intcol4 INT(N), intcol5 INT(N), charool1 VARCHAR (N) ,charcol2 VARCHAR (N), charcol3 VARCHAR(N), charcol4 VARCHAR(N), charcol5 VARCHAR (N) ,charcol6 VARCHAR (N), charcol7 VARCHAR(N), charcol8 VARCHAR(N), charcol9 VARCHAR (N) ,charcol10 VARCHAR (N)
B.SELECT intcol1, intcol2, intcol3, intcol4, intcol5, intcol6, intcol7, intcol8, intcol9, Intcol10, intcol11, intcol12, intcol13, intcol14, intcol15, intcol16, intcol17, intcol18, intcol19, charcol10 FROM t1 WHERE id = 's'
C.SELECT Select_priv, Repl_client_priv, Show_db_priv, Super_priv, Process_priv FROM mysql.user WHERE CONCAT (user,'s', host) = CURRENT_USER()
D.SELECT intcol1, intcol2, intcol3, intcol4, intcol5, charcol1, charcol2, charcol3, charcol4, charcol5, charcol6, charcol7, charcol8, charcol9, charcol10 FROM t1 WHERE id = 's'