[RUBY] Personal notes-Memo that you often forget and look up 2016.10

Rails

Rails server background startup

▼ Start the server in the background
rails s -d 

▼ Also open to the public
rails s -d -b 0.0.0.0

Python

Check if there is a specific element in the list

data = ["A","B" "C"]

if "B" in data:
    print("B is found")

Mongo

▼ Start
mongo

▼ Select db
use dbName

▼ Collection display
show collections

▼ Display of the number of documents
db.colName.count()

▼ When referring to a special collection name (numbers, hyphens, etc.)
db.getCollection('2016-09-01').  ...
Use getCollection in the form of.

▼ Get documents that meet specific conditions
db.colName.find({keyName:value}）

▼ Display all items
db.colName.find()

▼ csv export
mongoexport -d [Database name] -c [Collection name] -out[Output file name].csv --csv --fields xx,yy,zz

PHP

▼ Output an array
var_dump($array)

▼ Output JSON after arranging it

$json = '{"a":1,"b":2}';
$decode1 = json_decode($json)
$decode2 = json_decode($json)

//$decode1
object(stdClass)#1 (2) {
    ["a"] => int(1)
    ["b"] => int(2)
}

//$decode2
array(2) {
    ["a"] => int(1)
    ["b"] => int(2)
}

* Even though it is an array, if you use echo etc., "Error":I get an "Array to string conversion" error.
PHP I forgot after a long time^^;

▼ Output JSON beautifully
echo '<pre>';
var_dump($json);
echo '</pre>';

HTML (I rarely write it, so I'll forget it soon)

▼ Combo box
<select><option></option></select>

▼form
<form acition="..." method="...">
 <input type="text" name="name" size="20"/>
 <input type="submit" value="Send"/>
</form>

MySQL (I rarely write it, so I'll forget it soon)

▼ Start
mysql.server start

▼ Interactive IF
mysql -uroot -p

▼CREATE TABLE
CREATE TABLE {TABLENAME}(email varchar(100),name varchar(100));

▼ Primary key
CREATE TABLE {TABLENAME}(email varchar(100) PRIMARY KEY);

▼ Default value
CREATE TABLE {TABLENAME}(email varchar(100),complete bit(1) DEFAULT 0);

▼ Granting authority

·Authorization
GRANT ALL PRIVILEGES ON {TABLENAME}.* TO {USERNAME}@{HOSTNAME} IDENTIFIED BY {PASSWORD}

·Change Password
SET PASSWORD FOR username@"hostname"=password('Password after change');

▼ INSERT statement
INSERT INTO ｛TABLENAME} (email) VALUES ('[email protected]');

▼ Check the schema
show columns from {TABLENAME};

▼ Column operation

·add to
ALTER TABLE <table name> ADD <Column name> <Type information>;

·Change
ALTER TABLE test CHANGE num number int;

·Delete
ALTER TABLE <table name> DROP <Column name>;

・ Initial value setting
ALTER TABLE <table name> ALTER <Column name> SET DEFAULT <initial value>;

▼ Function
UPDATE test SET num = num+1 WHERE name = "hoge";

Nodejs

File input / output

▼ File output (overwrite)
fs.writeFile(filename, data, encoding='utf8', [callback])
fs.writeFileSync(filename, data, encoding='utf8', [callback])

* The top is asynchronous, the bottom is synchronous

▼ File output (additional note)
fs.appendFile(filename, data, encoding='utf8', [callback])
fs.appendFileSync(filename, data, encoding='utf8', [callback])

* The top is asynchronous, the bottom is synchronous

Terminal

Authority related

▼ Confirmation of authority
ls -l <File name or path>

▼ Granting authority
sudo chmod  <Access rights(Numbers)> <File name or path>

▼ Detailed authority settings
sudo chmod <Right holder>  + /-  <Access rights(Alphabet)> <File name or path>

▼ Owner change
chown root:root file