序列(SEQUENCES) this table are in the data dictionary:ALL_SEQUENCES ALL_SEQUENCES describes all sequences accessible to the user. Related views: DBA_SEQUENCES describes all sequences in the database. USER_SEQUENCES describes all sequences owned by the current user. This view does not display the SEQUENCE_OWNER column. Column Datatype NULL Description SEQUENCE_OWNER VARCHAR2(30) NOT NULL Name of the owner of the sequence SEQUENCE_NAME VARCHAR2(30) NOT NULL Sequence name MIN_VALUE NUMBER Minimum value of the sequence MAX_VALUE NUMBER Maximum value of the sequence INCREMENT_BY NUMBER NOT NULL Value by which sequence is incremented CYCLE_FLAG VARCHAR2(1) Does sequence wrap around on reaching limit ORDER_FLAG VARCHAR2(1) Are sequence numbers generated in order CACHE_SIZE NUMBER NOT NULL Number of sequence numbers to cache LAST_NUMBER NUMBER NOT NULL Last sequence number written to disk. If a sequence uses caching, the number written to disk is the last number placed in the sequence cache. This number is likely to be greater than the last sequence number that was usedSample: Create sequence myseq increment by 1 start with 10 nomaxvalue nocycle cache10;
satar with 就是开始值 increment by 1 是增长为1 cache 20 为每次增长为20对于以上触发器,每次插入数据触发触发器,插入到id
increment by 1 我知道是每次增长1 但是cache 20 为每次增长20就让我有点莫不着头脑
this table are in the data dictionary:ALL_SEQUENCES
ALL_SEQUENCES describes all sequences accessible to the user. Related views:
DBA_SEQUENCES describes all sequences in the database. USER_SEQUENCES describes all sequences owned by the current user. This view does not display the SEQUENCE_OWNER column. Column Datatype NULL Description
SEQUENCE_OWNER
VARCHAR2(30)
NOT NULL
Name of the owner of the sequence SEQUENCE_NAME
VARCHAR2(30)
NOT NULL
Sequence name MIN_VALUE
NUMBER
Minimum value of the sequence MAX_VALUE
NUMBER
Maximum value of the sequence INCREMENT_BY
NUMBER
NOT NULL
Value by which sequence is incremented CYCLE_FLAG
VARCHAR2(1)
Does sequence wrap around on reaching limit ORDER_FLAG
VARCHAR2(1)
Are sequence numbers generated in order CACHE_SIZE
NUMBER
NOT NULL
Number of sequence numbers to cache LAST_NUMBER
NUMBER
NOT NULL
Last sequence number written to disk. If a sequence uses caching, the number written to disk is the last number placed in the sequence cache. This number is likely to be greater than the last sequence number that was usedSample:
Create sequence myseq increment by 1 start with 10 nomaxvalue nocycle cache10;
increment by 1 是增长为1
cache 20 为每次增长为20对于以上触发器,每次插入数据触发触发器,插入到id
但是cache 20 为每次增长20就让我有点莫不着头脑