Examine this query which executes successfully: SELECT job, deptno FROM emp UNION ALL SELECT job, deptno FROM jobs_ history; What will be the result? A) It will return rows common to both SELECT state ...

Which three items does a direction of a relationship contain? A) an attribute B) a cardinality C) label D) an optionality E) a unique identifier F) an entity **** 本内容被作者隐藏 **** ...

Examine the description of the PRODCTS table which contains data: Name Null? Type ---------------------------------------------- PROD ID NOT NULL ...

Which two queries return the string Hello! we're ready? A) SELECT q'! Hello! We're ready! 'FROM DUAL; B) SELECT "Hello! We're ready "FROM |DUAL; C) SELECT q'[Hello! We're ready]'FROM DUAL; D) SELECT ' ...

Examine this description of the EMP table: Name Null? Type EMPNO NOT NULL NUMBER (4) ENAME VARCHAR2 (10) SAL ...

Which two are true about self joins? A) They are always equijoins. B) They require the NOT EXISTS operator in the join condition. C) They have no join condition. D)They can use INNER JOIN and LEFT JOI ...

Examine the data in the PRODUCTS table: PROD ID PROD NAME PROD LIST CATEGORY ID 101 Plate 10 ...

Which two are true about the USING clause when joining tables? A) All column names in a USING clause must be qualified with a table name or table alias. B) It can never be used with onatural join. C) ...