大约有 6,100 项符合查询结果（耗时：0.0338秒） [XML]
delete_all vs destroy_all?
I am looking for the best approach to delete records from a table. For instance, I have a user whose user ID is across many tables. I want to delete this user and every record that has his ID in all tables.
...
What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL?
... take up different amounts of space and they have different ranges of acceptable values.
Here are the sizes and ranges of values for SQL Server, other RDBMSes have similar documentation:
MySQL
Postgres
Oracle (they just have a NUMBER datatype really)
DB2
Turns out they all use the same specific...
What's the meaning of interface{}?
...ucted of two words of data:
one word is used to point to a method table for the value’s underlying type,
and the other word is used to point to the actual data being held by that value.
Addendum: This is were Russ's article is quite complete regarding an interface structure:
t...
Laravel 4 Eloquent Query Using WHERE with OR AND OR?
...', '=', $d);
})->get();
Will produce a query like:
SELECT * FROM <table> WHERE (a='foo' or b='bar') AND (c='john' or d='doe');
share
|
improve this answer
|
foll...
Cost of len() function
... the most common implementation of the Python language. Here's a link to a table that provides the algorithmic complexity of many different functions in CPython:
TimeComplexity Python Wiki Page
share
|
...
Get last record in a queryset
...
Django Doc:
latest(field_name=None) returns the latest object in the table, by date, using the field_name provided as the date field.
This example returns the latest Entry in the table, according to the
pub_date field:
Entry.objects.latest('pub_date')
...
Can JavaScript connect with MySQL?
... prefer it to pass through a MySQL Server (for example if you’re storing tables in InnoDB) then that can be configured.
JSDB offers a JS interface to DBs.
A curated set of DB packages for Node.js from sindresorhus.
sh...
MongoDB Show all contents from all collections
...of your database.
db.stats()
step 5: listing out all the collections(tables).
show collections
step 6:print the data from a particular collection.
db.'collection_name'.find().pretty()
share
|
...
CSS selector - element with a given child [duplicate]
...do (which helped in my case) is to select elements that have no children:
table td:empty
{
background-color: white;
}
Or have any children (including text):
table td:not(:empty)
{
background-color: white;
}
share
...
What does “static” mean in C?
...If we compile:
int i = 0;
static int si = 0;
and disassemble the symbol table with:
readelf -s main.o
the output contains:
Num: Value Size Type Bind Vis Ndx Name
5: 0000000000000004 4 OBJECT LOCAL DEFAULT 4 si
10: 0000000000000000 4 OBJECT GLOBAL DEFAULT...