大约有 47,000 项符合查询结果（耗时：0.0464秒） [XML]
Count the number of occurrences of a string in a VARCHAR field?
...
This should do the trick:
SELECT
title,
description,
ROUND (
(
LENGTH(description)
- LENGTH( REPLACE ( description, "value", "") )
) / LENGTH("value")
) AS count
FROM <tab...
App Inventor 2 项目合并工具 AIMerge · App Inventor 2 中文网
... CountDownScreen1 project, then clicking on the “Project” dropdown and selecting “Export selected project (.aia) to my computer”. Figure 4 shows how to select a project and where to click to download the project.
Figure 4: Steps to download the CountDownScreen1 project
Developer 2 Work I...
Check if a Postgres JSON array contains a string
...
As of PostgreSQL 9.4, you can use the ? operator:
select info->>'name' from rabbits where (info->'food')::jsonb ? 'carrots';
You can even index the ? query on the "food" key if you switch to the jsonb type instead:
alter table rabbits alter info type jsonb using ...
How to get the connection String from a database
... Visual Studio go to Tools -> Connect to Database.
2] Under Server Name Select your Database Server Name (Let the list Populate if its taking time).
3] Under Connect to a Database, Select Select or enter a database name.
4] Select your Database from Dropdown.
5] After selecting Database try Test ...
Browse the files created on a device by the iOS application I'm developing, on workstation?
...in the bottom half of the window.
In Xcode 6, go to Window -> Devices, select the device, select the app name under Installed Apps, click the settings gearbox, then select Download container.... In finder, double finger tap the package and select Show package contents.
...
get list of pandas dataframe columns based on data type
...
If you are just selecting columns by data type, then this answer is obsolete. Use select_dtypes instead
– Ted Petrou
Nov 3 '17 at 16:58
...
Left Join With Where Clause
...ring away rows where the left join doesn't succeed. Move it to the join:
SELECT `settings`.*, `character_settings`.`value`
FROM `settings`
LEFT JOIN
`character_settings`
ON `character_settings`.`setting_id` = `settings`.`id`
AND `character_settings`.`character_id` = '1'
...
Fetch the row which has the Max value for a column
... multiple rows for the userid where the maximum date is on multiple rows.
select userid,
my_date,
...
from
(
select userid,
my_date,
...
max(my_date) over (partition by userid) max_my_date
from users
)
where my_date = max_my_date
"Analytic functions rock"
Edi...
efficient way to implement paging
...inq (with SQL 2005 / 2008 as database server) your query will be using the Select ROW_NUMBER() Over ... statement, with is somehow direct paging in the SQL engine.
Giving you an example, I have a db table called mtcity and I wrote the following query (work as well with linq to entities):
using (Da...
How to list the tables in a SQLite database file that was opened with ATTACH?
...quently, if you used
ATTACH some_file.db AS my_db;
then you need to do
SELECT name FROM my_db.sqlite_master WHERE type='table';
Note that temporary tables don't show up with .tables either: you have to list sqlite_temp_master for that:
SELECT name FROM sqlite_temp_master WHERE type='table';
...