大约有 44,000 项符合查询结果（耗时：0.0425秒） [XML]
How to choose the id generation strategy when using JPA and Hibernate
...d
uses a database-generated GUID string on MS SQL Server and MySQL.
native
selects identity, sequence or hilo depending upon the capabilities of the underlying database.
assigned
lets the application assign an identifier to the object before save() is called. This is the default strategy if no elem...
- how to allow only one item selected?
I have a <SELECT multiple> field with multiple options and I want to allow it to have only one option selected at the same time but user can hold CTRL key and select more items at once.
...
How to find a table having a specific column in postgresql
...
you can query system catalogs:
select c.relname
from pg_class as c
inner join pg_attribute as a on a.attrelid = c.oid
where a.attname = <column name> and c.relkind = 'r'
sql fiddle demo
...
Symbol for any number of any characters in regex?
I'm wondering is there a symbol for any number (including zero) of any characters
5 Answers
...
OnNotify函数 ON_NOTIFY消息总结 - C/C++ - 清泛网 - 专注C/C++及内核技术
...，我们实现下自定义notify.
1.定义通知类型:
#define WM_GRID_SELECT_CHANGE(WM_USER + 1)
2.增加消息映射函数，并实现：
afx_msg void OnNotifyGridChanged(NMHDR *pNMHDR, LRESULT *pResult);
3.增加映射对应关系：
ON_NOTIFY(WM_GRID_SELECT_CHANGE, GRIDCTRL_ID, &CContrad...
What does the “__block” keyword mean?
...c NSInteger CounterStatic;
{
NSInteger localCounter = 42;
__block char localCharacter;
void (^aBlock)(void) = ^(void) {
++CounterGlobal;
++CounterStatic;
CounterGlobal = localCounter; // localCounter fixed at block creation
localCharacter = 'a'; // sets ...
PostgreSQL return result set as JSON array?
...
TL;DR
SELECT json_agg(t) FROM t
for a JSON array of objects, and
SELECT
json_build_object(
'a', json_agg(t.a),
'b', json_agg(t.b)
)
FROM t
for a JSON object of arrays.
List of objects
This section de...
MySQL和MongoDB设计实例进行对比 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...并且外观设计是直板的手机，需按照如下方式查询：
SELECT * FROM `mobile_params` WHERE name = '待机时间' AND value > 100;
SELECT * FROM `mobile_params` WHERE name = '外观设计' AND value = '直板';
注：参数表为了方便，把数值和字符串统一保存成字...
Eclipse git checkout (aka, revert)
...ing" view, right click the deleted file in the "Unstaged Changes" list and select "Replace with HEAD Revision"
– Vlasta Dolejs
Sep 5 '17 at 8:03
add a comment
...
Adding an identity to an existing column
... )
ON [PRIMARY]
go
SET IDENTITY_INSERT dbo.Tmp_Names ON
go
IF EXISTS ( SELECT *
FROM dbo.Names )
INSERT INTO dbo.Tmp_Names ( Id, Name )
SELECT Id,
Name
FROM dbo.Names TABLOCKX
go
SET IDENTITY_INSERT dbo.Tmp_Names OFF
go
DROP...