大约有 40,000 项符合查询结果（耗时：0.0428秒） [XML]
Storing JSON in database vs. having a new column for each key
I am implementing the following model for storing user related data in my table - I have 2 columns - uid (primary key) and a meta column which stores other data about the user in JSON format.
...
SQL order string as number
... cast your column value to an integer explicitly with
select col from yourtable
order by cast(col as unsigned)
or implicitly for instance with a mathematical operation which forces a conversion to number
select col from yourtable
order by col + 0
BTW MySQL converts strings from left to right....
Is the NOLOCK (Sql Server hint) bad practice?
...dated at the same time another process may be selecting data from the same table. If this happens a lot then there's a high probability of deadlocks unless you use a database mode such as READ COMMITED SNAPSHOT.
I have since changed my perspective on the use of NOLOCK after witnessing how it can i...
GUI Tool for PostgreSQL [closed]
.... I only have one database, and it takes me 6 clicks to open up my list of tables, then a right click and view in a separate window just to see the data in a table. I do not recommend it.
– CorayThan
Oct 21 '14 at 19:15
...
CSS center display inline block?
...e.
This solution does not require fixed width, which would have been unsuitable for me as my button's text will change.
Here is a CodePen demo and a snippet of the relevant code below:
.parent {
display: flex;
justify-content: center;
align-items: center;
}
.child {
display: i...
How to show SQL queries run in the Rails console?
...lain
=> EXPLAIN for: SELECT "categories".* FROM "categories" 0|0|0|SCAN TABLE categories
EXPLAIN for: SELECT "categories_products".* FROM "categories_products" WHERE "categories_products"."category_id" IN (1, 2) 0|0|0|SCAN TABLE categories_products
EXPLAIN for: SELECT "products".* FROM "product...
Worst security hole you've seen? [closed]
...
little Bobby tables strikes again... xkcd.com/327
– gbjbaanb
Oct 7 '09 at 12:21
86
...
ERROR 1044 (42000): Access denied for user ''@'localhost' to database 'db'
...'localhost';
Syntax:
mysql> grant all privileges on `database_name`.`table_name` to 'user_name'@'hostname';
Note:
hostname can be IP address, localhost, 127.0.0.1
In database_name/table_name, * means all databases
In hostname, to specify all hosts use '%'
Step [3]: Get ou...
How to order by with union in SQL?
...olas Carey - when I initially tested using a UNION it was behaving unpredictably as you described, I think the UNION ALL (at least in Oracle) was necessary to order the top SELECT above the bottom. However I've provided an alternate that does guarantee correct ordering and should be database indepe...
How to update gradle in android studio?
... desired gradle version)
File→Project Structure→Project
The following table shows compatibility between Android plugin for Gradle and Gradle:
Latest stable versions you can use with Android Studio 4.0.1 (July 2020):
Android Plugin version: 4.0.1
Gradle version: 6.1.1
Official links
Version ...