If a unique constraint is defined on column COL1 of table TAB1, what are the characteristics of COL1?（）A、COL1 will accept NULL values and can be referenced in another table's foreign key specification.B、COL1 will not accept NULL values and cannot be refer

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第3题：

Given the following DDL and INSERT statements: CREATE VIEW v1 AS SELECT col1 FROM t1 WHERE col1 > 10; CREATE VIEW v2 AS SELECT col1 FROM v1 WITH CASCADED CHECK OPTION; CREATE VIEW v3 AS SELECT col1 FROM v2 WHERE col1 < 100; INSERT INTO v1 VALUES(5); INSERT INTO v2 VALUES(5); INSERT INTO v3 VALUES(20); INSERT INTO v3 VALUES(100); How many of these INSERT statements will be successful?（）

• A、0
• B、1
• C、2
• D、3

正确答案:C

第4题：

What type of constraint is used to ensure that each row inserted into the EMPLOYEE table with a value in the WORKDEPT column has a row with a corresponding value in the DEPTNO column of the DEPARTMENT table?（）

• A、A check constraint on the EMPLOYEE table
• B、A unique constraint on the EMPLOYEE table WORKDEPT column
• C、A foreign key reference from the DEPARTMENT tables DEPTNO column to the WORKDEPT column of the EMPLOYEE table
• D、A foreign key reference from the EMPLOYEE tables WORKDEPT column to the DEPTNO column of the DEPARTMENT table

正确答案:D

第5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 T1
• D、insert into T2（col1，col2，col3） select col1，col2，col3 from T1；

正确答案:D

第6题：

Given the following requirements: Create a table to contain employee data, with a unique numeric identifier automatically assigned when a row is added, has an EDLEVEL column that permits only the values 'C', 'H' and 'N', and permits inserts only when a corresponding value for the employee's department exists in the DEPARTMENT table. Which of the following CREATE statements will successfully create this table?（）

• A、CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED ALWAYS AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1), PRIMARY KEY emp_pk (empno), FOREIGN KEY emp_workdept_fk ON (workdept) REFERENCES department (deptno), CHECK edlevel_ck VALUES (edlevel IN ('C','H','N')), );
• B、CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK edlevel VALUES ('C','H','N') );
• C、CREATE TABLE emp ( empno SMALLINT NEXTVAL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3) NOT NULL, edlevel CHAR(1) CHECK IN ('C','H','N')), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY department (deptno) REFERENCES (workdept) );
• D、CREATE TABLE emp ( empno SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY, firstname VARCHAR(30) NOT NULL, lastname VARCHAR(30) NOT NULL, workdept CHAR(3), edlevel CHAR(1), CONSTRAINT emp_pk PRIMARY KEY (empno), CONSTRAINT emp_workdept_fk FOREIGN KEY (workdept) REFERENCES department (deptno), CONSTRAINT edlevel_ck CHECK (edlevel IN ('C','H','N')) );

正确答案:D

第7题：

The following statements: CREATE TABLE t1 (col1 INT NOT NULL, PRIMARY KEY(col1)); CREATE TABLE t2 (col1 INT NOT NULL, col2 CHAR(1) NOT NULL, PRIMARY KEY (col1, col2), FOREIGN KEY (col1) REFERENCES t1 (col1) ON DELETE CASCADE ON UPDATE RESTRICT); CREATE TABLE t3 (col1 INT NOT NULL, col2 INT NOT NULL, PRIMARY KEY (col1, col2),FOREIGN KEY (col1) REFERENCES t1 (col1) ON DELETE NO ACTION ON UPDATE RESTRICT);INSERT INTO t1 VALUES (1), (2); INSERT INTO t2 VALUES (1, 'a'), (1, 'b'), (2,'c'); INSERT INTO t3 VALUES (1, 100), (2, 200), (2,300); How many rows will be deleted by the following DELETE statement? DELETE FROM t1 WHERE col1= 1;（）

• A、4
• B、3
• C、1
• D、0

正确答案:D

第8题：

Which two statements are true about the primary key constraint in a table？ （）

• A、It is not possible to disable the primary key constraint.
• B、It is possible to have more than one primary key constraint in a single table.
• C、The primary key constraint can be referred by only one foreign key constraint.
• D、The primary key constraint can be imposed by combining more than one column.
• E、The non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.

正确答案:D,E

第9题：

Which SQL statement defines the FOREIGN KEY constraint on the DEPTNO column of the EMP table?（）

• A、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) NOT NULL CONSTRAINT emp_deptno_fk FOREIGN KEY deptno REFERENCES dept deptno);
• B、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) CONSTRAINT emp_deptno_fk REFERENCES dept (deptno));
• C、CREATE TABLE EMP (empno NUMBER(4) ename VARCHAR2(35), deptno NUMBER(7,2) NOT NULL, CONSTRAINT emp_deptno_fk REFERENCES dept (deptno) FOREIGN KEY (deptno));
• D、CREATE TABLE EMP (empno NUMBER(4), ename VARCNAR2(35), deptno NUMBER(7,2) FOREIGN KEY CONSTRAINT emp deptno fk REFERENCES dept (deptno));

正确答案:B

第10题：

Which two statements are true regarding single row functions?（）

• A、They accept only a single argument 
• B、They can be nested only to two levels 
• C、Arguments can only be column values or constants 
• D、They always return a single result row for every row of a queried table 
• E、They can return a data type value different from the one that is referenced

正确答案:D,E

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第15题：

Which of the following scenarios will ensure that the value of the NEXT_STEPNO column in a given row of table TABLEX exists as a value of column STEPNO (usually in another row) in the same table?（）

• A、Define a UNIQUE constraint on the columns NEXT_STEPNO and STEPNO.
• B、Define a CHECK constraint on the NEXT_STEPNO column (NEXT_STEPNO = STEPNO).
• C、Define column STEPNO as the primary key of TABLEX and column NEXT_STEPNO as a foreign key referencing column STEPNO of the same table.
• D、Define column NEXT_STEPNO as the primary key of TABLEX and column STEPNO as a foreign key referencing column NEXT_STEPNO in the same table.

正确答案:C

第16题：

对于表A（col1 int，col2 char（1））更新col1=1的数据col2值为N，下面语句正确的是（）

• A、update table A setcol2=’N’ where col1=1
• B、modify table A setcol2=N where col1=1
• C、update A set col2=’N’ where col1=1
• D、modify A set col2=N where col1=1

正确答案:D

第17题：

Given the following statements: CREATE TABLE tab1 (col1 INT); CREATE TABLE tab2 (col1 INT); CREATE TRIGGER trig1 AFTER UPDATE ON tab1 REFERENCING NEW AS new1 FOR EACH ROW MODE DB2SQL INSERT INTO tab2 VALUES(new1.col1); INSERT INTO tab1 VALUES(2),(3); What is the result of the following query? SELECT count(*) FROM tab2;（）

• A、3
• B、2
• C、1
• D、0

正确答案:D

第18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.

正确答案:C

第19题：

Given two collection objects referenced by col1 and col2，which of these statements are true？（）

• A、The operation col1.retainAll（col2） will not modify the col1 object.
• B、The operation col1.removeAll（col2） will not modify the col2 object.
• C、The operation col1.addAll（col2） will return a new collection object， containing elements from both col1      and col2.
• D、The operation col1.containsAll（Col2） will not modify the col1 object.

正确答案:B,D

第20题：

Which two statements are true about constraints? （）

• A、The UNIQUE constraint does not permit a null value for the column.
• B、A UNIQUE index gets created for columns with PRIMARY KEY and UNIQUE constraints.
• C、The PRIMARY KEY and FOREIGN KEY constraints create a UNIQUE index.
• D、The NOT NULL constraint ensures that null values are not permitted for the column.

正确答案:B,D

第21题：

Given the following requirements:Create a table named TESTTAB, which has an identity column named ACTIVITYNO. Define the identity column to generate the values for the column by default. Start the values at 10 and increment by 10. Make the identity column unique. Which of the following CREATE statements will successfully create this table?（）

• A、CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 10 INCREMENT BY 10), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTIVITYNO))
• B、CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH 1 INCREMENT BY 10), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTNO))
• C、CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 1), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTIVITYNO))
• D、CREATE TABLE TESTTAB (ACTIVITYNO SMALLINT NOT NULL GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 10), ACTKWD CHAR(6) NOT NULL, ACTDESC VARCHAR(20) NOT NULL, UNIQUE(ACTIVITYNO))

正确答案:D

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