CYCLE NO CYCLE The CYCLE option allows the sequence to wrap around when the maxvalue or minvalue has been reached by an ascending or descending sequence respectively. If the limit is reached, the next number generated will be the minvalue or maxvalue, respectively. For NO CYCLE, any calls ...
nextid number;//声明一个number型的nextid begin//只要发生插入事务,就开始触发 IF :new.personId IS NULL or :new.perosnId=0 THEN //如果该行的personId为空那么 select S_t_person.nextval into nextid from sys.dual;//就把序列的下一个值赋值个之前创建的nextid :new.personId:=nextid;//然后把...
{ FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ] [...] ] from_item 可以是以下选项之一: [ ONLY ] table_name [ * ] [ [ AS ] alias [ ( column_alias [,...
TheCYCLEallows you to restart the value if the limit is reached. The next number will be the minimum value for the ascending sequence and the maximum value for the descending sequence. If you useNO CYCLE, when the limit is reached, attempting to get the next value will result in an error...
跟ORACLE语法区别之处 1. Update和delete语法区别 Pg 和MySQL Update和delete的时候表名不能加别名 2. 插入数字类型不一样 ORACLE 对number类型的数据可以用’’ 字符串标记插入，但是PG不行，必须要进行正确的数据类型 3. SEQ使用不同 ORACEL的SEQ 是 SELECT SEQ,NEXT_VAL FROM DUAL PG 使用方法select nextval...
数据类型 名字别名描述 bigint int8 有符号的8字节整数 bigserial serial8 自动增长的8字节整数 bit [ (n) ] 定长位串 bit varying [ (n) ] varbit 变长位串 boolean bool 逻辑布尔值(真/假) box 平面上的普通方框 b
Latest checkpoint's NextXID:0:514Latest checkpoint's NextOID:16408... redo日志(WAL) 默认保存在$PGDATA/pg_wal目录下,如下所示: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 [postgres@pgprimary data]$ ls pg_wal00000002000000000000000900000003000000000000000900000003000000000000000B archive_status0000000...
[ASC|DESC|USINGoperator][NULLS{FIRST|LAST}][,...]][LIMIT{count|ALL}][OFFSETstart[ROW|ROWS]][FETCH{FIRST|NEXT}[count]{ROW|ROWS}ONLY][FOR{UPDATE|NOKEYUPDATE|SHARE|KEYSHARE}[OFtable_name[,...]][NOWAIT|SKIPLOCKED][...]]#from_item 可以是以下选项之一[ONLY]table_name[*][[AS]alias[(...
Log Sequence Number(LSN) LSN是一个64位的整数,表示WAL记录在日志文件中的偏移,通过LSN可以在日志文件里定位到对应的WAL记录。 postgres=#selectpg_current_wal_lsn();pg_current_wal_lsn---1/16AA580(1row) LSN可以用形如'1/16AA580'的字符串形式表示,'1' 是uin64的高32位的16进制表示(10进制为1)...
[ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ] [...] ] #from_item 可以是以下选项之一 [ ONLY ] table_name [ * ] [ [ AS ] alias [ ( column_...