原来只知道用Oracle, 因为没有自增列(像mssql), 所以采用一种叫"自动采番"的方式. 今天终于知道了这种Sequence, 类似"自动采番"的方式, 好像一个表一样, 只要从它里面取值, 它就可以自动按步长增长. 创建: CREATE SEQUENCE test_sequence INCREMENT BY 1--每次加的个数据 START WITH 1--从1开始计数 NOMA...
算出当前值，和你要修改的值的差（正负都可以）假设为 100 alter sequence SEQ_name increment by 100 nocache;select SEQ_name.nextval from dual;alter sequence SEQ_name increment by 1 cache 20;select LAST_NUMBER from all_sequences where sequence_name='SEQ_'UPDATE all_sequences ...
select any sequence NOTE: The alternative to sequences used in other RDBMS products is autonumbering and keeping the current number in a table. Both of these other methods demand serialization as they can only dispense one number at a time.Table example: CREATE TABLE seqnum ( next_number NUMB...
Oracle/PLSQL: Sequences (Autonumber) In Oracle, you can create an autonumber field by using sequences. A sequence is an object in Oracle that is used to generate a number sequence. This can be useful when you need to create a unique number to act as a primary key. The syntax for a ...
在Oracle数据库中,可以通过以下SQL语句来查看数据库中的序列: ="hljs">="hljs-keyword">SELECTsequence_name ="hljs-keyword">FROMuser_sequences; 该查询将返回当前用户下所有的序列名称。如果想要查看所有用户的序列,可以使用以下SQL语句: ="hljs">="hljs-keyword">SELECTsequence_name ="hljs-keyword">FRO...
OceanBase 数据库 SQL 型 V4.3.5 参考指南 系统视图 Oracle 租户系统视图 字典视图 DBA_SEQUENCES 更新时间:2025-04-04 23:00:01 编辑 功能 展示当前租户下的所有序列。 说明 从V2.2.77 版本开始引入。 字段说明 字段名称类型是否可以为 NULL描述
(1)创建 CREATE SEQUENCE SEQUENCENAME minvalue：序列最小值 maxvalue/nomaxvalue：序列最大值/没有...
Hi, I am new to MySQL. Can some one tell me if MySQL has sequences to generate primary key values, like Oracle? or, if it doesn't have sequences, then what alternate option does MySQL offer to generate primary key values? Thanks in Advanvce. Amir....
Oracle 18c introduced scalable sequences: a special class of sequences that are optimized for multiple concurrent session usage. This introduces three new options when creating a new sequence: SCALE— Turns on the sequence scalability feature. EXTEND— Extends in additional 6...
SQL> create sequence seq_1; Sequence created. SQL> select seq_1.currval from dual; select seq_1.currval from dual * ERROR at line 1: ORA-08002: sequence SEQ_1.CURRVAL is not yet defined in this session SQL> select seq_1.nextval from dual; ...