Which two statements are true about the DUAL table?B) It can be accessed only by the SYS user.D) It can display multiple rows but only a single column.F) It can be used to display only constants or pseudo columns.(解析:dual 这个虚拟的表可以显示多行多列;任何用户都可以访问它。这道题...【阅读全文】
Which three statements are true about GLOBAL TEMPORARY TABLES?B) A GLOBAL TEMPORARY TABLE can have multiple indexesD) Data Manipulation Language (DML) on GLOBAL TEMPORARY TABLES generates no REDO.F) A tigger can be created on a GLOBAL TEMPORARY TABLE(解析:全局临时表跟普通表一样,...【阅读全文】
Which two statements are true about transactions in the Oracle Database serve?B) Data Manipulation Language (DML) statements always start a new transaction.D) A Data Detiniton Language (DDL) statement does a commit automatially only for the data dictionary updates caused by the DDLF) I...【阅读全文】
In the PROMOTIONS table, the PROMO_BEGTN_DATE columm is of datatype DATE and the default date format is DD-MON-RR.A) TO_NUMBER(PROMO_ BEGIN_DATE) - 5 will return numberC) PROMO_BEGIN_DATE - SYSDATE will return a number.E) PROMO_BEGIN_DATE - SYSDATE will return an error.(解析:这道...【阅读全文】
Examine this partial command:cust_id NUMBER(2),)Which two clauses are required for this command to execute successfully?B) the REJECT LIMIT clauseD) the ACCESS PARAMETERS clauseAnswer:AD【阅读全文】
Examine the description of the PRODUCTS table:-----------------------------------------------------------------PRODUCT_NANE VARCHAR2(10)PURCHARGE &nb...【阅读全文】
Which three statements are true about dropping and unused columns in an Oracle database?B) A DROP COLUMN command can be rolled backD) An UNUSED column's space is redaimed automatially when the row containing that column is next queried.F) A column that is set to NNUSED still counts tow...【阅读全文】
Which two statements are true about a self join?B) It can be a left outer join.D) It can be an inner join.Answer:BD不过在进行内连接时为了区别表的名字,需要加别名from emp2 won w.mgr=m.empno;)【阅读全文】
Which two statements are true about Oracle synonyms?B) All private synonym names must be unique in the database.D) A synonym can be created on an object in a package.(解析:同义词也是 Oracle 的一个对象;【阅读全文】
Which three statements are true about views in an Orade batabase?B) Rows inserted into a table using a view are retained in the table if the view is doppedD) Views have no segment.F) A view can be created that refers to a non-existent table in its defining query.(解析:...【阅读全文】