给定下列表: 下列哪一个语句会产生所需结果?()
A: SELECT UNIQUE * FROM tab1
B: SELECT DISTINCT * FROM tab1
C: SELECT UNIQUE(*) FROM tab1
D: SELECT DISTINCT(*) FROM tab1
A: SELECT UNIQUE * FROM tab1
B: SELECT DISTINCT * FROM tab1
C: SELECT UNIQUE(*) FROM tab1
D: SELECT DISTINCT(*) FROM tab1
举一反三
- 给定下列两个表:()。 A: SELECT * FROM tab1 INNER JOIN tab2 ON col_1 = col_a B: SELECT * FROM tab1 LEFT OUTER JOIN tab2 ON col_1 = col_a C: SELECT * FROM tab1 RIGHT OUTER JOIN tab2 ON col_1 = col_a D: SELECT * FROM tab1 FULL OUTER JOIN tab2 ON col_1 = col_a
- 与SELECT TAB1.* FROM TAB1 WHERE InStr([简历],"篮球")<>0功能相同的语句是( )。 A: A) SELECT TAB1.* FROM TAB1 WHERE TAB1.简历 Like "篮球" B: B) SELECT TAB1.* FROM TAB1 WHERE TAB1.简历 Like "*篮球" C: C) SELECT TAB1.* FROM TAB1 WHERE TAB1.简历 Like "*篮球*" D: D) SELECT TAB1.* FROM TAB1 WHERE TAB1.简历 Like "篮球*\
- 与SELECT TAB1.* FROM TAB1 WHERE InStr([简历],"篮球")<>0功能相同的语句是______。 A: SELECT TAB1.* FROM TAB1 WHERE TAB1. 简历 Like "篮球" B: SELECT TAB1.* FROM TAB1 WHERE TAB1. 简历 Like "*篮球" C: SELECT TAB1.* FROM TAB1 WHERE TAB1. 简历 Like "*篮球*" D: SELECT TAB1.* FROM TAB1 WHERE TAB1. 简历 Like "篮球*\
- 下面的语句按顺序成功执行后 CREATE TABLE tab1 (c1 CHAR(1))INSERT INTO tab1 VALUES ('b')CREATE VIEW view1 AS SELECT c1 FROM tab1 WHERE c1 ='a'INSERT INTO view1 VALUES ('a')INSERT INTO tab1 VALUES ('b')执行SELECT c1 FROM tab1可以选择出多少条记录?( ) A: 0 B: 1 C: 2 D: 3
- 数据库系统管理员按照事务的方式执行下面的语句: Create table tab1 (a int,b int) insert into tabl values(1,2) insert into tab1 values(2,3) commit Insert into tab1 values(2,3) Insert into tab1 values(1,6) Commit Delete from tab1 where a=1 Insert into tab1 values(1,7) Delete from tab1 where a=1 Insert into tab1 values(1,8) 数据库系统突然崩溃,系统重新启动后,该管理员执行 Select count(*) from tab1 数据库系统的输出是多少? A: 6 B: 3 C: 4 D: 5