注意看红色字体,这就是新增加的语法,字段ts和te是数据变化的起止时间和结束时间。 另外用ALTER TABLE更改表结构,语法如下: ALTER TABLE t1 ADD COLUMN ts TIMESTAMP(6) GENERATED ALWAYS AS ROW START, ADD COLUMN te TIMESTAMP(6) GENERATED ALWAYS AS ROW END,
另外用ALTER TABLE更改表结构,语法如下: ALTER TABLE t1 ADD COLUMN ts TIMESTAMP(6) GENERATED ALWAYS AS ROW START, ADD COLUMN te TIMESTAMP(6) GENERATED ALWAYS AS ROW END, ADD PERIOD FOR SYSTEM_TIME(ts, te), ADD SYSTEM VERSIONING; 1. 2. 3. 4. 二、查询历史数据 这里我们做一个实验,首先要...
x INT, start_trxid BIGINT UNSIGNED GENERATED ALWAYS AS ROW START, end_trxid BIGINT UNSIGNED GENERATED ALWAYS AS ROW END, PERIOD FOR SYSTEM_TIME(start_trxid, end_trxid) ) WITH SYSTEM VERSIONING; SELECT * FROM t FOR SYSTEM_TIME AS OF TRANSACTION 12345; 第七部分 当前数据和历史分离存储 当...
`ts` timestamp(6) GENERATED ALWAYS AS ROW START, `te` timestamp(6) GENERATED ALWAYS AS ROW END, PERIOD FOR SYSTEM_TIME (`ts`, `te`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 WITH
| +---+---+ | tasks | CREATE TABLE `tasks`（ `id` varchar(35）GENERATED ALWAYS AS （json_compact(json_extract(`doc`,'$._id'))）VIRTUAL, `doc` longtext CHARACTER SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL
在创建列类型后面添加: GENERATED ALWAYS AS ($表达式$) 如果是计算列, MySql 有两种方式:Virtual 和 Stored。 MariaDb 称为: Virtual 和 Presistent 5. 血的教训. 分页必须要有 order by 诡异的情况: group by broker_id , dealer_id limit #{take} , #{skip} 获取所有的数据时, 出现重复数据....
Sintassi <type> [GENERATED ALWAYS] AS ( <espressione&g... CREATE DATABASE Sintassi CREATE [OR REPLACE] {DATABASE | SCHEMA} [IF NOT EXISTS] nome_db [specifica_cre CREATE EVENT Sintassi CREATE [OR REPLACE] [DEFINER = { utente | CURRENT_USER | role | CURRENT_ROLE } ...
[ <type_value> COLLATE <collation_name>GENERATED ALWAYS AS (<expression>)[VIRTUAL | STORED][CONSTRAINT] <constraint_name> CHECK (<expression>) ][ <type_value> GENERATED ALWAYS AS (<expression>)[VIRTUAL | STORED][ [CONSTRAINT] <constraint_name> CHECK (<expression>) ] ] Column constraint...
| data_type [GENERATED ALWAYS] AS ( <expression> ) {VIRTUAL | PERSISTENT} [UNIQUE] [UNIQUE KEY] [COMMENT'string']index_col_name:col_name [(length)] [ASC | DESC]index_type:USING {BTREE | HASH | RTREE}index_option:KEY_BLOCK_SIZE [=] value ...
: t2 Create Table: CREATE TABLE `t2` ( `id` varchar(35) GENERATED ALWAYS AS (json_compact(json_extract(`doc`,'$. _id'))) VIRTUAL, `doc` longtext SET utf8mb4 COLLATE utf8mb4_bin DEFAULT NULL CHE CK (json_valid(`doc`)), UNIQUE KEY `id` (`id`), CONSTRAINT `id_not_...