OCP-1Z0-051-V9.02-43题
43. Evaluate the following CREATE SEQUENCE statement:CREATE SEQUENCE seq1START WITH 100INCREMENT BY 10MAXVALUE 200CYCLENOCACHE;The SEQ1 sequence has generated numbers up to the maximum limit of 200. You issue the followingSQL statement:SELECT seq1.nextval FROM dual;What is displayed by the SELECT statement?A. 1B. 10C. 100D. an errorAnswer: A 答案解析：参考：http://blog.iyunv.com/rlhua/article/details/12776779实验验证：1、首先创建这个序列sh@TESTDB> CREATE SEQUENCE seq12START WITH 1003INCREMENT BY 104MAXVALUE 2005CYCLE6NOCACHE; Sequence created. 2、查看值。sh@TESTDB> select seq1.nextval from dual; NEXTVAL---------- 100 sh@TESTDB> select seq1.currval from dual; CURRVAL---------- 100 3、因为该序列是循环的，到达最大值后从最小值MINVALUE开始循环，该序列因为省略MINVALUE省略，所以默认为NOMINVALUE最小值为 1，所有又从1开始。sh@TESTDB> select seq1.nextval from dual; NEXTVAL---------- 200 sh@TESTDB>sh@TESTDB> select seq1.nextval from dual; NEXTVAL---------- 1故答案选A
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