在此示例中,我们使用 createQueryBuilder 方法构建查询,使用 ROW_NUMBER() OVER (ORDER BY user.age) 函数为每行生成一个基于年龄排序的行号。然后,我们选择所需的列并将结果作为原始结果(包含行号)返回。 getUsersWithRowNumber 函数将返回一个对象数组,每个对象都包含 row_number、id、name 和age 属性。 注意...
复制代码 使用窗口函数(Window Function):窗口函数可以在查询中为每一行分配一个行号,从而实现分页功能。例如,要获取第10到20行的数据,可以这样写: WITH numbered_rows AS ( SELECT *, ROW_NUMBER() OVER (ORDER BY some_column) as row_number FROM your_table ) SELECT * FROM numbered_rows WHERE row_num...
Counts INT; BEGIN --总记录条数 EXECUTE 'SELECT COUNT(*) from ( ' || StrCondition || ' ) A' INTO Counts; --总页码 PageCount:=CEIL(CAST(Counts AS NUMERIC)/CAST(PageSize AS NUMERIC)); --翻页的记录明细 FOR select_result IN EXECUTE 'SELECT * FROM ( SELECT *,ROW_NUMBER() OVER ( ...
在PostgreSQL中,可以使用函数来返回表及其总计数。下面是一个示例函数: 代码语言:txt 复制 CREATE OR REPLACE FUNCTION get_table_with_count() RETURNS TABLE(table_name text, total_count bigint) AS $$ BEGIN RETURN QUERY SELECT table_name, count(*) AS total_count FROM information_schema.tables WHERE ...
createtriggertrg_employees_changebeforeinsertorupdateordeleteonemployeesforeachrowexecutefunctiontrack_employees_change(); 至此,我们完成了触发器的创建。接下来进行一些数据测试: insertintoemployees(employee_id,first_name,last_name,email,phone_number,hire_date,job_id,salary,commission_pct,manager_id,department...
_function EndDirectModify; /* Functions for SELECT FOR UPDATE/SHARE row locking */ GetForeignRowMarkType_function GetForeignRowMarkType; RefetchForeignRow_function RefetchForeignRow; RecheckForeignScan_function RecheckForeignScan; /* Support functions for EXPLAIN */ ExplainForeignScan_function Explain...
This one includes plpgsql, row_number window functions, sequences, and regexp_split_to_table. Advent of Code - Day 9 SQL Solutions for Day 9 of Advent of Code. This one uses a custom function and colored ASCII art. Advent of Code - Day 10 SQL Solutions for Day 10 of Advent of ...
Postgres-XL 一款开源的PG集群软件,XL代表eXtensible Lattice,即可扩展的PG“格子”之意。它是一个完全满足ACID的、开源的、可方便进行水平扩展的、多租户安全的、基于PostgreSQL的数据库解决方案。 与Pgpool不同的是,Postgres-XL是在PG源代码的基础上增加新功能实现的。它将PG的SQL解析层的工作和数据存取层的工作分离...
(1 row) Time: 93.481 ms postgres=# select * from test where id=19990000; id | info | crt_time ---+---+--- 19990000 | | (1 row) Time: 89.114 ms postgres=# explain select * from test where id=19990000; QUERY PLAN --- Append (cost=0.00..8.30 rows=2 width=48) -> Seq Scan...
(1 row) 1. 2. 3. 4. 5. 6. 7. 使用heap_page_items 方法查看test表对应page header中的内容 postgres=# select * from heap_page_items(get_raw_page('test',0)); lp | lp_off | lp_flags | lp_len | t_xmin | t_xmax | t_field3 | t_ctid | t_infomask2 | t_infomask | t_...