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【单项选择题】

Given that tables T1 and T2 contain the following rows: Table T1:<br /> C1 C2<br /> 5 4 5 2 5 5<br /> Table T2: C1 C2 5 1 5 2 5 3<br /> Which of the following queries will return only those rows that exist in T1 and not in T2?（）<p> Given that tables T1 and T2 contain the following rows: Table T1:<br /> C1 C2<br /> 5 4 5 2 5 5<br /> Table T2: C1 C2 5 1 5 2 5 3<br /> Which of the following queries will return only those rows that exist in T1 and not in T2?（）</p>

A、A.SELECT * FROM T1 MINUS SELECT * FROM T2

B、B.SELECT * FROM T1 EXCEPT SELECT * FROM T2

C、C.SELECT * FROM T2 UNION EXCEPT SELECT * FROM T1

D、D.SELECT * FROM T1 NOT EXISTS SELECT * FROM T2

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更多“Given that tables T1 and T2 contain the following rows: Table T1:<br /> C1 C2<br /> 5 4 5 2 5 5<br /> Table T2: C1 C2 5 1 5 2 5 3<br /> Which of the following queries will return only those rows that exist in T1 and not in T2?（）<p> Given that tables T1 and T2 contain the following rows: Table T1:<br /> C1 C2<br /> 5 4 5 2 5 5<br /> Table T2: C1 C2 5 1 5 2 5 3<br /> Which of the following queries will return only those rows that exist in T1 and not in T2?（）</p>”相关的问题
第1题
[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 t2  B、SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2  C、SELECT * FROM t1 INTERSECT SELECT * FROM t2  D、SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)  

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第2题
[单选题] A user needs to create a trigger that will update table T2 whenever a row is added to table T1. Assuming the user has all appropriate privileges for table T2, which privilege is required on table T1 to create the trigger?（）

A、REFERENCES  B、SELECT  C、UPDATE  D、ALTER  

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第3题
[单选题] A view is created with the following statement:CREATE VIEW v1 AS SELECT col1, col2, col3, col4 FROM t1 WHERE col4 > 1000 WITH CHECK OPTIONWhat is the effect of the CHECK OPTION clause?（）

A、Any row inserted or updated through view V1 must meet the condition that col4 > 1000.  B、From now on, any row inserted or updated in table T1 must meet the condition that col4 > 1000, but existing rows in the table are not checked.  C、At view creation, DB2 will check the data in table T1, and if in any row doesn't meet the condition col4 > 1000, the view creation will be rejected.  D、Any row inserted or updated through view V1 must meet the condition that col4 > 1000 and no row in table T1 can be updated such that col4 <= 1000, but new rows in the table can be inserted with col4 <= 1000.  

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第4题
[单选题] Given that t1 is a reference to a live thread, which is true?（）

A、The Thread.sleep() method can take t1 as an argument.  B、The Object.notify() method can take t1 as an argument.  C、The Thread.yield() method can take t1 as an argument.  D、The Thread.setPriority() method can take t1 as an argument.  E、The Object.notify() method arbitrarily chooses which thread to notify.  

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第5题
[多选题] In a test database, you issue the SELECT … INTO OUTFILE statement to create a file with your t1 table data. You then TRUNCATE this table to empty it.（） Mysql＞ SELECT * INTO OUTFILE '/tmp/t1.sql' from t1; mysql＞ TRUNCATE t1;

A、$ mysqladmin – u root – p – h localhost test – restore /tmp/t1.sql  B、Mysql＞ INSERT INTO t1 VALUES FROM '/tmp/t1.sql'  C、$ mysql – u root – p – h localhost test ＜ /tmp/t1.sql  D、Mysql＞ LOAD DATA INFILE '/tmp/t1.sql' INTO TABLE t1  E、$ mysqlinport – u root – p – h localhost test /tmp/t1.sql  

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第6题
[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 t2  B、SELECT * FROM t1 UNION DISTINCT SELECT * FROM t2  C、SELECT * FROM t1 INTERSECT SELECT * FROM t2  D、SELECT * FROM t1 WHERE (c1,c2)= (SELECT c1,c2 FROM t2)  

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第7题
[单选题] When defining a referential constraint between the parent table T2 and the dependent table T1, which of the following is true?（）

A、The list of column names in the FOREIGN KEY clause can be a subset of the list of column names in the primary key of T2 or a UNIQUE constraint that exists on T2.  B、The list of column names in the FOREIGN KEY clause can be a subset of the list of column names in the primary key of T1 or a UNIQUE constraint that exists on T1.  C、The list of column names in the FOREIGN KEY clause must be identical to the list of column names in the primary key of T2 or a UNIQUE constraint that exists on T2.  D、The list of column names in the FOREIGN KEY clause must be identical to the list of column names in the primary key of T1 or a UNIQUE constraint that exists on T1.  

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第8题
[] Assuming PUBLIC has been granted all privileges on table T1, which of the following statements would continue to permit any user to add rows to table T1, but not remove them?（）

A、A.REVOKE DROP ON t1 FROM PUBLIC  B、B.REVOKE UPDATE ON t1 FROM PUBLIC  C、C.REVOKE DELETE ON t1 FROM PUBLIC  D、D.REVOKE CONTROL ON t1 FROM PUBLIC  

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第9题
[] The datum from which the predicted heights of tides are reckoned in the tide tables is（）.

A、A.mean low water  B、B.the same as that used for the charts of the locality  C、C.the highest possible level  D、D.given in table three of the tide tables  

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