PostgreSQL 创建视图的语法为:CREATE [ OR REPLACE ] [ TEMP | TEMPORARY ] [ RECURSIVE ] VIEW `name` [ ( column_name [, ...] ) ] [ WITH ( view_option_name [= view_option_value] [, ... ] ) ] AS query [ …
1. CREATE OR REPLACE VIEW 按照"CREATE OR REPLACE VIEW" 关键字搜索,这部分代码在ATExecCmd函数(tablecmds.c文件)。可以看到它对应的命令类型叫AT_AddColumnToView,对应操作为调用ATExecAddColumn函数为视图新加列。 /* * ATExecCmd: dispatch a subcommand to appropriate execution routine */ static void AT...
回到最开始视图的案例本身,先创建个索引: create index idx_student_classid_stu_date on student(stu_classid,stu_date); explain analyze -- create or replace view view_student as select /*+ parallel(s 4 hard) IndexOnlyScan(s idx_student_classid_stu_date) */ sc.cls_id, count(distinct stu_...
一、创建视图 create or replace viewvw_usersasselect * from users; 二、通过定义规则来更新视图 create rulevw_users_updas on update tovw_usersdo instead updateusers set user_email=New.user_email; updatevw_userssetuser_email='zhangsan@163.com'whereid=1; 注意,经过测试在9.5以上的版本可以直接使用...
CREATE OR REPLACE view_name AS query PostgreSQL 目前只支持追加视图定义中的字段,不支持减少字段或者修改字段的名称或顺序。例如,我们可以为视图 emp_details_view 增加一个字段 hire_date: create or replace view emp_details_view as select e.employee_id, e.job_id, e.manager_id, e.department_id, d...
CREATE [ OR REPLACE ] VIEW name [ ( column_name [, ...] ) ] AS query DEALLOCATE 删除一个准备好的查询。 DEALLOCATE [ PREPARE ] plan_name DECLARE 定义一个游标。 DECLARE name [ BINARY ] [ INSENSITIVE ] [ [ NO ] SCROLL ] CURSOR [ { WITH | WITHOUT } HOLD ] FOR query ...
--方式一:创建视图时带约束检查 postgres=# create or replace view employees_it as postgres-# select employee_id, postgres-# first_name, postgres-# last_name, postgres-# email, postgres-# phone_number, postgres-# hire_date, postgres-# job_id,manager_id, postgres-# department_id postgres-#...
SYSID uid | [ ENCRYPTED | UNENCRYPTED ] PASSWORD 'password' | CREATEDB | NOCREATEDB | CREATEUSER | NOCREATEUSER | IN GROUP group_name [, ...] | VALID UNTIL 'abs_time'CREATE VIEW定义一个视图。CREATE [ OR REPLACE ] VIEW name [ ( column_name [, ...] ) ] AS query...
CREATE [OR REPLACE] TRIGGER trigger_name {BEFORE | AFTER } {INSERT | DELETE | UPDATE [OF column [, column …]]} [OR {INSERT | DELETE | UPDATE [OF column [, column …]]}...] ON [schema.]table_name | [schema.]view_name
application_name is '应用名(客户端名)'; create or replace view pg_log as select * from pg_log_mon union all select * from pg_log_tue union all select * from pg_log_wed union all select * from pg_log_thu union all select * from pg_log_fri union all select * from pg_log_sat...