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For relation R where primary key contains multiple attributes,no non-key attribute should be functionally dependent on a part of the primary key. This relation R is at least in
A． 1NF
B．2NF
C．3NF
D．BCNF
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更多 “ For relation R where primary key contains multiple attributes,no non-key attribute should be functionally dependent on a part of the primary key. This relation R is at least inA． 1NFB．2NFC．3NFD．BCNF ” 相关考题
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Which values are NOT permitted to be part of the primary key?A．alpha-numeric charactersB．punctuationC．special charactersD．NULL
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为表TEST中ID列添加主键约束的语法是（）A、ALTER TABLE TEST CHANGE（ ID INT PRIMARY KEY）B、ALTER TABLE TEST ADD（ ID INT PRIMARY KEY）C、ALTER TABLE TEST MODIFY（ ID INT PRIMARY KEY）D、ALTER TABLE TEST ADD CONSTRAINT PK PRIMARY KEY （ID）
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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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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.
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he data blocks in your form module are based on object tables. How would you create a master-detail relationship between two of these blocks?（）A、Use the Data Block Wizard and base the relation on a REF pointer. B、In the Object Navigator, select the Relation node under the master block and click the Create icon. Build the relation manually and coordinate the blocks using triggers.C、Use the Data Block Wizard, and base the relation on the primary key-foreign key relationship in the database. D、This task is not possible because master-detail relations can be implemented only for blocks based on relational tables.
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Where can you add your own PL/SQL code in relation-handling triggers?（）A、Before the "End default relation program section" comment. B、After the "Begin default relation program section" comment. C、Before the "Begin default relation program section" comment. D、It is not possible to modify the relation-handling code that Forms automatically creates for relations.
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You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty.Which statement accomplishes this task?（）A、ALTER TABLE students ADD PRIMARY KEY student_id;B、ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student _ id);C、ALTER TABLE students ADD CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);D、ALTER TABLE students MODIFY CONSTRAINT stud _ id _pk PRIMARY KEY (student _ id);
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Which statements are correct regarding indexes？ （）A、 When a table is dropped， the corresponding indexes are automatically dropped.B、 For each DML operation performed， the corresponding indexes are automatically updated.C、 Indexes should be created on columns that are frequently referenced as part of an expression.D、 A non-deferrable PRIMARY KEY or UNIQUE KEY constraint in a table automatically creates a uniqueindex.
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In the COURSE_ENROLLMENT form module, you define a master-detail relation between the COURSES_OFFERED data block and the STUDENT data block, respectively. To implement block coordination, which statement must be true?（）A、 The Enforce Primary Key property on the STUDENT block is set to Yes. B、 The Alias property on the COURSES_OFFERED block is set to Student. C、 The Copy Value from item property on the foreign key item in the STUDENT blocks is set to the primary key item of the COURSES_OFFERED block. D、 The Synchronize with item property on the foreign key item in the STUDENT block is set to the primary key item of the COURSES_OFFERED block.
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单选题You need to modify the STUDENTS table to add a primary key on the STUDENT_ID column. The table is currently empty. Which statement accomplishes this task?（）A
ALTER TABLE students ADD PRIMARY KEY _ id;B
ALTER TABLE students ADD CONSTRAINT PRIMARY KEY (student_id);C
ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY student_id;D
ALTER TABLE students ADD CONSTRAINT stud_id_pk PRIMARY KEY (student_id);E
ALTER TABLE students MODIFY CONSTRAINT stud_id_pk PRIMARY KEY (student_id);
考题
单选题he data blocks in your form module are based on object tables. How would you create a master-detail relationship between two of these blocks?（）A
Use the Data Block Wizard and base the relation on a REF pointer. B
In the Object Navigator, select the Relation node under the master block and click the Create icon. Build the relation manually and coordinate the blocks using triggers.C
Use the Data Block Wizard, and base the relation on the primary key-foreign key relationship in the database. D
This task is not possible because master-detail relations can be implemented only for blocks based on relational tables.
考题
多选题Which two statements are true about the primary key constraint in a table？ （）AIt is not possible to disable the primary key constraint.BIt is possible to have more than one primary key constraint in a single table.CThe primary key constraint can be referred by only one foreign key constraint.DThe primary key constraint can be imposed by combining more than one column.EThe non-deferrable primary key constraint creates an unique index on the primary key column if it is not already indexed.
考题
单选题In the COURSE_ENROLLMENT form module, you define a master-detail relation between the COURSES_OFFERED data block and the STUDENT data block, respectively. To implement block coordination, which statement must be true?（）A
The Enforce Primary Key property on the STUDENT block is set to Yes. B
The Alias property on the COURSES_OFFERED block is set to Student. C
The Copy Value from item property on the foreign key item in the STUDENT blocks is set to the primary key item of the COURSES_OFFERED block. D
The Synchronize with item property on the foreign key item in the STUDENT block is set to the primary key item of the COURSES_OFFERED block.
考题
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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