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(难度：中等)已知表T1中有2行数据，T2中有3行数据，执行SQL语句“select a.* from T1 a,T2 b”后，返回的行数为6
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更多 “(难度：中等)已知表T1中有2行数据，T2中有3行数据，执行SQL语句“select a.* from T1 a,T2 b”后，返回的行数为6” 相关考题
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Which of the following SQL statements will return the year and average salary for all employees hired within a given year that have a salary greater than $30,000?()
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Given that tables T1 and T2 contain the following rows:Table T1: C1 C2 1 4 1 3 1 2Table T2: C1 C2 1 1 1 2 1 3Which of the following queries will return only those rows that exist in both T1 and T2?()
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Given that tables T1 and T2 contain the following rows: Table T1:C1 C25 4 5 2 5 5Table T2: C1 C2 5 1 5 2 5 3Which of the following queries will return only those rows that exist in T1 and not in T2?()
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Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 1 4 1 3 1 2 Table T2: C1 C2 1 1 1 2 1 3 Which of the following queries will return only those rows that exist in both T1 and T2?（）A、SELECT * FROM t1 UNION SELECT * FROM t2B、SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2C、SELECT * FROM t1 INTERSECT SELECT * FROM t2D、SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
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现有客户表customers（主键：客户编号cid），包含10行数据，订单表orders（外键：客户编号cid），包含6条数据。执行sql语句：select * from customers right outer join orders on customers.cid=orders.cid。最多返回（）条记录。A、10B、6C、4D、0
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Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 5 4 5 2 5 5 Table T2: C1 C2 5 1 5 2 5 3 Which of the following queries will return only those rows that exist in T1 and not in T2?（）A、SELECT * FROM T1 MINUS SELECT * FROM T2B、SELECT * FROM T1 EXCEPT SELECT * FROM T2C、SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1D、SELECT * FROM T1 NOT EXISTS SELECT * FROM T2
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Which of the following SQL statements will return the year and average salary for all employees hired within a given year that have a salary greater than $30,000?（）A、SELECT * FROM t1 UNION SELECT * FROM t2B、SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2C、SELECT * FROM t1 INTERSECT SELECT * FROM t2D、SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
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单选题Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 1 4 1 3 1 2 Table T2: C1 C2 1 1 1 2 1 3 Which of the following queries will return only those rows that exist in both T1 and T2?（）A
SELECT * FROM t1 UNION SELECT * FROM t2B
SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2C
SELECT * FROM t1 INTERSECT SELECT * FROM t2D
SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
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单选题Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 5 4 5 2 5 5 Table T2: C1 C2 5 1 5 2 5 3 Which of the following queries will return only those rows that exist in T1 and not in T2?（）A
SELECT * FROM T1 MINUS SELECT * FROM T2B
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单选题现有客户表customers（主键：客户编号cid），包含10行数据，订单表orders（外键：客户编号cid），包含6条数据。执行sql语句：select * from customers right outer join orders on customers.cid=orders.cid。最多返回（）条记录。A
10B
6C
4D
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单选题存在两个结构相同的数据库表T1（col1，col2，col3）、T2（col1，col2，col3），写出一SQL语句将所有T1数据导入到T2表（）A
select col1，col2，col3 from T1 into T2（col1，col2，col3）B
insert T1 （col1，col，col3） into T2（col1，col2，col3）C
insert into T2 （col1，col2，col3） as select col1，col2，col3 from T1D
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单选题Which of the following SQL statements will return the year and average salary for all employees hired within a given year that have a salary greater than $30,000?（）A
SELECT * FROM t1 UNION SELECT * FROM t2B
SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2C
SELECT * FROM t1 INTERSECT SELECT * FROM t2D
SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
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单选题Which of the following SQL statements will return the year and average salary for all employees hired within a given year that have a salary greater than $30,000?（）A
SELECT * FROM t1 UNION SELECT * FROM t2B
SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2C
SELECT * FROM t1 INTERSECT SELECT * FROM t2D
SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
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单选题Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 1 4 1 3 1 2 Table T2: C1 C2 1 1 1 2 1 3 Which of the following queries will return only those rows that exist in both T1 and T2?（）A
SELECT * FROM t1 UNION SELECT * FROM t2B
SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2C
SELECT * FROM t1 INTERSECT SELECT * FROM t2D
SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
考题
单选题Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 5 4 5 2 5 5 Table T2: C1 C2 5 1 5 2 5 3 Which of the following queries will return only those rows that exist in T1 and not in T2?（）A
SELECT * FROM T1 MINUS SELECT * FROM T2B
SELECT * FROM T1 EXCEPT SELECT * FROM T2C
SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1D
SELECT * FROM T1 NOT EXISTS SELECT * FROM T2
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单选题Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 5 4 5 2 5 5 Table T2: C1 C2 5 1 5 2 5 3 Which of the following queries will return only those rows that exist in T1 and not in T2?（）A
SELECT * FROM T1 MINUS SELECT * FROM T2B
SELECT * FROM T1 EXCEPT SELECT * FROM T2C
SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1D
SELECT * FROM T1 NOT EXISTS SELECT * FROM T2
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单选题Given that tables T1 and T2 contain the following rows: Table T1: C1 C2 1 4 1 3 1 2 Table T2: C1 C2 1 1 1 2 1 3 Which of the following queries will return only those rows that exist in both T1 and T2?（）A
SELECT * FROM t1 UNION SELECT * FROM t2B
SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2C
SELECT * FROM t1 INTERSECT SELECT * FROM t2D
SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)
考题
单选题现有客户表customers（主键：客户编号cid），包含10行数据，订单表orders（外键：客户编号cid），包含6条数据。执行sql语句：select * from customers right outer join orders on customers.cid=orders.cid。最多返回（）条记录。A
10B
6C
4D
0
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(难度：中等)SQL中有一种简便的插入多行数据的方法，这种方法是使用select语句查询出的结果代替VALUES子句。
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