A frequent use case when transducing is to apply a transformation to items without changing the type of the collection. In this lesson, we'll create a helper to do just that. seq will be similar to into, except the target type will be inferred from t…

Our transduce function is powerful but requires a lot of boilerplate. It would be nice if we had a way to transduce into arrays and objects without having to specify the inner reducer behaviour, i.e. how to build up values, since a given collection t…

So far we've been transducing by manually calling .reduce() on arrays, but we want to be able to transduce over other collection types as well. In this lesson we'll create a transduce function to support transducing over any data structure that imple…

create sequence seq_test start with 3 increment by 1 minvalue 1  --范围-(1027 -1) maxvalue 999999999999999999999999999 ; --范围1028-1 先 seq_test.nextval ,后 seq_test.currval select seq_test.nextval from dual; select seq_test.currval from dual; create sequ…

oracle创建序列化: CREATE SEQUENCE seq_itv_collection            INCREMENT BY 1  -- 每次加几个              START WITH 1399       -- 从1开始计数              NOMAXVALUE        -- 不设置最大值              NOCYCLE               -- 一直累加,不循环              CACHE 10; oracle修改序列…

Oracle新表使用序列(sequence)作为插入值,初始值不是第一个,oraclesequence 使用oracle11g插入数据时遇到这样一个问题: 1 --创建测试表-- 2 CREATE TABLE tbl_test( 3 test_id NUMBER PRIMARY KEY, 4 test_name VARCHAR2(20) 5 ); 6 7 --为tbl_test创建序列-- 8 CREATE SEQUENCE seq_test 9 INCREMENT BY 1 -- 每次加几个…

create table sequence (      seq_name        VARCHAR(50)  NOT NULL COMMENT '序列名称',    min_val         INT  UNSIGNED         NOT NULL COMMENT '最小值',    max_val         INT  UNSIGNED         NOT NULL COMMENT '最大值',    if_cycle        INT  UNSIGNED     …

Oracle提供了sequence对象,由系统提供自增长的序列号,每次取的时候它会自动增加,通常用于生成数据库数据记录的自增长主键或序号的地方. sequence的创建需要用户具有create sequence或者create any sequence的权限. 1.创建sequence create sequence seq_nameINCREMENT BY 1 -- 每次加几个 START WITH 1 -- 从1开始计数 NOMAXvalue -- 不设置最大值(最小值:minvalue,最…

Once again, in this series of posts I look at the parts of the .NET Framework that may seem trivial, but can help improve your code by making it easier to write and maintain. The index of all my past little wonders posts can be found here. We've seen…

在Oracle数据库中,sequence等同于序列号,每次取的时候sequence会自动增加,一般会作用于需要按序列号排序的地方. 1.Create Sequence (注释:你需要有CREATE SEQUENCE或CREATE ANY SEQUENCE权限) CREATE SEQUENCE emp_sequence INCREMENT BY 1 —— 每次加几个 START WITH 1 —— 从1开始计数 NOMAXVALUE —— 不设置最大值 NOCYCLE —— 一直累加,不循环 CA…