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@@ -89,6 +89,7 @@ Feel free to take a look. You might learn new things. They have been designed to
|
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#### SQL
|
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- [MySQL](databases/mysql.sh)
|
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- [PostgreSQL](databases/postgresql.md)
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#### NoSQL
|
||||
|
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|
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@@ -16,69 +16,3 @@ GRANT ALL PRIVILEGES ON prospectwith.* TO 'power'@'localhost' WITH GRANT OPTION;
|
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CREATE USER 'newuser'@'localhost' IDENTIFIED BY 'password'; # Create user
|
||||
|
||||
mysql -u root -pmypassword -e "MY SQL QUERY" &>> query.log & disown # Run SQL query in the background
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|
||||
# *****************************************************************************
|
||||
# Database and Table Operations
|
||||
# *****************************************************************************
|
||||
|
||||
CREATE DATABASE database_name; # Create a new database
|
||||
DROP DATABASE database_name; # Delete a database
|
||||
CREATE TABLE table_name (column1 datatype, column2 datatype, ...); # Create a new table
|
||||
DROP TABLE table_name; # Delete a table
|
||||
SHOW TABLES; # Display all tables in the current database
|
||||
DESCRIBE table_name; # Show the structure of a table
|
||||
|
||||
# *****************************************************************************
|
||||
# Data Manipulation
|
||||
# *****************************************************************************
|
||||
|
||||
INSERT INTO table_name (column1, column2, ...) VALUES (value1, value2, ...); # Insert data into a table
|
||||
UPDATE table_name SET column1 = value1, column2 = value2, ... WHERE condition; # Update existing data in a table
|
||||
DELETE FROM table_name WHERE condition; # Delete data from a table
|
||||
SELECT column1, column2, ... FROM table_name WHERE condition; # Select data from a table
|
||||
|
||||
# *****************************************************************************
|
||||
# Backup and Restore
|
||||
# *****************************************************************************
|
||||
|
||||
mysqldump -u username -p database_name table1 table2 > file.sql # Backup specific tables
|
||||
mysql -u username -p database_name < file.sql # Restore specific tables
|
||||
|
||||
# *****************************************************************************
|
||||
# User Management and Security
|
||||
# *****************************************************************************
|
||||
|
||||
REVOKE privilege_type ON database_name.table_name FROM 'username'@'hostname'; # Revoke privileges from a user
|
||||
DROP USER 'username'@'hostname'; # Delete a user
|
||||
ALTER USER 'username'@'hostname' IDENTIFIED BY 'newpassword'; # Reset a user's password
|
||||
|
||||
# *****************************************************************************
|
||||
# Performance and Maintenance
|
||||
# *****************************************************************************
|
||||
|
||||
OPTIMIZE TABLE table_name; # Optimize a table
|
||||
ANALYZE TABLE table_name; # Analyze a table for key distribution and storage optimization
|
||||
CHECK TABLE table_name; # Check a table for errors
|
||||
REPAIR TABLE table_name; # Repair a corrupted table
|
||||
|
||||
# *****************************************************************************
|
||||
# Advanced Queries
|
||||
# *****************************************************************************
|
||||
|
||||
SELECT ... FROM table1 JOIN table2 ON table1.column = table2.column; # Perform a join operation between two tables
|
||||
SELECT ... FROM (SELECT ... FROM table_name) AS subquery; # Use a subquery within another query
|
||||
SELECT column, COUNT(*) FROM table_name GROUP BY column; # Group results and use aggregate functions
|
||||
|
||||
# *****************************************************************************
|
||||
# System Information
|
||||
# *****************************************************************************
|
||||
|
||||
SELECT VERSION(); # Show the current version of MySQL
|
||||
SELECT User, Host FROM mysql.user; # List all current MySQL users
|
||||
|
||||
# *****************************************************************************
|
||||
# Miscellaneous
|
||||
# *****************************************************************************
|
||||
|
||||
SET GLOBAL general_log = 'ON'; # Enable query logging
|
||||
SHOW FULL PROCESSLIST; # Show the last queries executed in MySQL
|
||||
|
||||
494
databases/postgresql.md
Normal file
494
databases/postgresql.md
Normal file
@@ -0,0 +1,494 @@
|
||||
## ❄ PostgreSQL CHEAT SHEET
|
||||
|
||||
### 🧐 What is PostgreSQL?
|
||||
`PostgreSQL/Postgres` is a free open-source relational database management system(RDBMS) emphasizing extensibility and SQL compliance. It was originally named `POSTGRES`, referring to it's origins as a successor to the Ingres database developed at the University of California, Berkeley.
|
||||
|
||||
### 🤔 What is the use of PostgreSQL?
|
||||
It is a highly stable database management system, backend by more than 20 years of community development which has contributed to it's high levels of resilience, integrity, and correctness. PostgreSQL is used as the primary data store or data warehouse for many web, mobile, geospatial, and analytics applications.
|
||||
|
||||
## 📚 PostgreSQL Table of Contents
|
||||
|
||||
### 1️⃣ QUERYING DATA FROM A TABLE
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t;
|
||||
```
|
||||
Query data in columns c1, c2 from a table
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT * FROM t;
|
||||
```
|
||||
Query all rows and columns from a table
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t
|
||||
WHERE condition;
|
||||
```
|
||||
Query data and filter rows with a condition
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT DISTINCT c1 FROM t
|
||||
WHERE condition;
|
||||
```
|
||||
Query distinct rows from a table
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t
|
||||
ORDER BY c1 ASC[DESC];
|
||||
```
|
||||
Sort the result set in ascending or descending order
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t
|
||||
ORDER BY c1
|
||||
LIMIT n OFFSET offset;
|
||||
```
|
||||
Skip offset of rows and return the next n rows
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, aggregate(c2)
|
||||
FROM t
|
||||
GROUP BY c1;
|
||||
```
|
||||
Group rows using in aggregate function
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, aggregate(c2)
|
||||
FROM t
|
||||
GROUP BY c1
|
||||
HAVING condition;
|
||||
```
|
||||
Filter groups using HAVING clause
|
||||
</details>
|
||||
|
||||
### 2️⃣ QUERYING FROM MULTIPLE TABLES
|
||||
<details>
|
||||
<summary>View Queries </summary>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1
|
||||
INNER JOIN t2 ON condition;
|
||||
```
|
||||
Inner join t1 and t2
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1
|
||||
LEFT JOIN t2 ON condition;
|
||||
```
|
||||
Left join t1 and t1
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1
|
||||
RIGHT JOIN t2 ON condition;
|
||||
```
|
||||
Right join t1 and t2
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1
|
||||
FULL OUTER JOIN t2 ON condition;
|
||||
```
|
||||
Perform full outer join
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1
|
||||
CROSS JOIN t2;
|
||||
```
|
||||
Produce a Cartesian product of rows in tables
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1, t2;
|
||||
```
|
||||
Another way to perform cross join
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1 A
|
||||
INNER JOIN t2 B ON condition;
|
||||
```
|
||||
Join t1 to itself using INNER JOIN clause
|
||||
|
||||
</details>
|
||||
|
||||
### 3️⃣ USING SQL OPERATORS
|
||||
<details>
|
||||
<summary>View Queries </summary>
|
||||
|
||||
```
|
||||
SELECT c1, c2
|
||||
FROM t1
|
||||
UNION [ALL]
|
||||
SELECT c1, c2 FROM t2;
|
||||
```
|
||||
Combine rows from two queries
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t1
|
||||
INTERSECT
|
||||
SELECT c1, c2 FROM t2;
|
||||
```
|
||||
Return the intersection of two queries
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t1
|
||||
EXCEPT
|
||||
SELECT c1,c2 FROM t2;
|
||||
```
|
||||
Subtract a result set from another result set
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t
|
||||
WHERE c1[NOT] LIKE pattern;
|
||||
```
|
||||
Query rows using pattern matching %, _
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t
|
||||
WHERE c1[NOT] IN value_list;
|
||||
```
|
||||
Query rows in a list
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t
|
||||
WHERE c1 BETWEEN low_value AND high_value;
|
||||
```
|
||||
Query rows between two values
|
||||
<hr>
|
||||
|
||||
```
|
||||
SELECT c1, c2 FROM t
|
||||
WHERE c1 IS [NOT]NULL;
|
||||
```
|
||||
Check if values in a table is NULL or not
|
||||
</details>
|
||||
|
||||
### 4️⃣ MANAGING TABLES
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
```
|
||||
CREATE TABLE(
|
||||
id SERIAL PRIMARY KEY,
|
||||
name VARCHAR NOT NULL,
|
||||
price NUMERIC(10,2) DEFAULT 0
|
||||
);
|
||||
```
|
||||
Create a new table with three columns
|
||||
<hr>
|
||||
|
||||
```
|
||||
DROP TABLE t CASCADE;
|
||||
```
|
||||
Delete the table from the database
|
||||
<hr>
|
||||
|
||||
```
|
||||
ALTER TABLE t ADD column;
|
||||
```
|
||||
Add a new column to the table
|
||||
<hr>
|
||||
|
||||
```
|
||||
ALTER TABLE t DROP COLUMN c;
|
||||
```
|
||||
Drop column c from the table
|
||||
<hr>
|
||||
|
||||
```
|
||||
ALTER TABLE t ADD contraint;
|
||||
```
|
||||
Add a constraint
|
||||
<hr>
|
||||
|
||||
```
|
||||
ALTER TABLE t DROP constraint;
|
||||
```
|
||||
Drop a constraint
|
||||
<hr>
|
||||
|
||||
```
|
||||
ALTER TABLE t1 RENAME TO t2;
|
||||
```
|
||||
Rename a table from t1 to t2
|
||||
<hr>
|
||||
|
||||
```
|
||||
ALTER TABLE t1 RENAME c1 to c2;
|
||||
```
|
||||
Rename column c1 to c2
|
||||
<hr>
|
||||
|
||||
```
|
||||
TRUNCATE TABLE t CASCADE;
|
||||
```
|
||||
Remove all data in a table
|
||||
</details>
|
||||
|
||||
### 5️⃣ USING SQL CONSTRAINTS
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
```
|
||||
CREATE TABLE t(
|
||||
c1 INT, c2 INT, c3 VARCHAR,
|
||||
PRIMARY KEY(c1, c2)
|
||||
);
|
||||
```
|
||||
Set c1 and c2 as a primary key
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE TABLE t1(
|
||||
c1 SERIAL PRIMARY KEY,
|
||||
c2 INT,
|
||||
FOREIGN KEY (c2) REFERENCES ts(c2)
|
||||
);
|
||||
```
|
||||
Set c2 column as a foreign key
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE TABLE t(
|
||||
c1 INT, c1 INT,
|
||||
UNIQUE(c2, c3)
|
||||
);
|
||||
```
|
||||
Make the values in c1 and c2 unique
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE TABLE t(
|
||||
c1 INT, c INT,
|
||||
CHECK(c1 > 0 AND c1 >= c2)
|
||||
);
|
||||
```
|
||||
Ensure c1 > 0 and values in c1 >= c2
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE TABLE t(
|
||||
c1 SERIAL PRIMARY KEY,
|
||||
c2 VARCHAR NOT NULL
|
||||
);
|
||||
```
|
||||
Set values in c2 column not null
|
||||
</details>
|
||||
|
||||
### 6️⃣ MODIFIYING DATA
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
```
|
||||
INSERT INTO t(column_list)
|
||||
VALUES(value_list);
|
||||
```
|
||||
Insert one row into a table
|
||||
<hr>
|
||||
|
||||
```
|
||||
INSERT INTO t(column_list)
|
||||
VALUES(value_list),
|
||||
(value_list), ....;
|
||||
```
|
||||
Insert multiple rows into a table
|
||||
<hr>
|
||||
|
||||
```
|
||||
INSERT INTO t1(column_list)
|
||||
SELECT column_list
|
||||
FROM t2;
|
||||
```
|
||||
Insert rows from t2 into t1
|
||||
<hr>
|
||||
|
||||
```
|
||||
UPDATE t
|
||||
SET c1 = new_value;
|
||||
```
|
||||
Update new value in the column c1 for all rows
|
||||
<hr>
|
||||
|
||||
```
|
||||
UPDATE t
|
||||
SET c1 = new_value,
|
||||
c2 = new_value
|
||||
WHERE condition;
|
||||
```
|
||||
Update values in the column c1, c2 that match the condition
|
||||
<hr>
|
||||
|
||||
```
|
||||
DELETE FROM t;
|
||||
```
|
||||
Delete all data in a table
|
||||
<hr>
|
||||
|
||||
```
|
||||
DELETE FROM t
|
||||
WHERE condition;
|
||||
```
|
||||
Delete subset of rows in a table
|
||||
</details>
|
||||
|
||||
### 7️⃣ MANAGING VIEWS
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
```
|
||||
CREATE VIEW v(c1, c2)
|
||||
AS
|
||||
SELECT c1, c2
|
||||
FROM t;
|
||||
```
|
||||
Create a new view that consists of c1 and c2
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE VIEW v(c1, c2)
|
||||
AS
|
||||
SELECT c1, c2
|
||||
FROM t
|
||||
WITH[CASCADED | LOCAL]CHECK OPTION;
|
||||
```
|
||||
Create a new view with check option
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE RECURSIVE VIEW v
|
||||
AS
|
||||
select-statement --anchor part
|
||||
UNION[ALL]
|
||||
select-statement; --recursive part
|
||||
```
|
||||
Create a recursive view
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE TEMPORARY VIEW v
|
||||
AS
|
||||
SELECT c1, c2
|
||||
FROM t;
|
||||
```
|
||||
Create a temporary view
|
||||
<hr>
|
||||
|
||||
```
|
||||
DROP VIEW view_name;
|
||||
```
|
||||
Delete a view
|
||||
</details>
|
||||
|
||||
|
||||
### 8️⃣ MANAGING INDEXES
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
```
|
||||
CREATE INDEX inx_name
|
||||
ON t(c1, c2);
|
||||
```
|
||||
Create an index on c1 and c2 of the table t
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE UNIQUE INDEX inx_name
|
||||
ON t(c3, c4);
|
||||
```
|
||||
Create unique index on c3, c4 of the table t
|
||||
<hr>
|
||||
|
||||
```
|
||||
DROP INDEX idx_name;
|
||||
```
|
||||
Drop an index
|
||||
</details>
|
||||
|
||||
|
||||
### 9️⃣ MANAGING TRIGGERS
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
```
|
||||
CREATE OR MODIFY TRIGGER trigger_name
|
||||
WHEN EVENT
|
||||
ON table_name TRIGGER_TYPE
|
||||
EXECUTE stored_procedure;
|
||||
```
|
||||
Create or modify a trigger
|
||||
<hr>
|
||||
|
||||
```
|
||||
WHEN
|
||||
```
|
||||
- BEFORE - invoke before the event occurs
|
||||
- AFTER - invoke after the event occurs
|
||||
<hr>
|
||||
|
||||
```
|
||||
EVENT
|
||||
```
|
||||
- INSERT - invoke for INSERT
|
||||
- UPDATE - invoke for UPDATE
|
||||
- DELETE - invoke for DELETE
|
||||
<hr>
|
||||
|
||||
```
|
||||
TRIGGER_TYPE
|
||||
```
|
||||
- FOR EACH ROW
|
||||
- FOR EACH STATEMENT
|
||||
<hr>
|
||||
|
||||
```
|
||||
CREATE TRIGGER before_insert_person
|
||||
BEFORE INSERT
|
||||
ON person FOR EACH ROW
|
||||
EXECUTE stored_procedure;
|
||||
```
|
||||
Create a trigger invoked before a new row is inserted into the person table
|
||||
<hr>
|
||||
|
||||
```
|
||||
DROP TRIGGER trigger_name
|
||||
```
|
||||
Delete a specific trigger
|
||||
</details>
|
||||
|
||||
|
||||
### 🔟 SQL AGGREGATE FUNCTIONS
|
||||
<details>
|
||||
<summary>View Queries</summary>
|
||||
|
||||
- AVG - returns the average of a list
|
||||
- COUNT - returns the number of elements of a list
|
||||
- SUM - returns the total of a list
|
||||
- MAX - returns the maximum value in a list
|
||||
- MIN - returns the minimum value in a list
|
||||
</details>
|
||||
@@ -88,7 +88,7 @@ CHEATSHEET C#
|
||||
string newStr = oldStr.Replace("old","new");
|
||||
|
||||
//IndexOf
|
||||
//Finds the first occurrence of a string in a larger string
|
||||
//Finds the first ocurrence of a string in a larger string
|
||||
//Returns -1 if the string is not found
|
||||
String.IndexOf(val, start, num)
|
||||
val - string to search for
|
||||
@@ -102,7 +102,7 @@ CHEATSHEET C#
|
||||
String.Split(Char[]);
|
||||
|
||||
//ToCharArray
|
||||
//Places selected characters in a string in a char array
|
||||
//Places selected characteres in a string in a char array
|
||||
String str = "AaBbCcDd";
|
||||
//create array of 8 vowels
|
||||
var chars = str.ToCharArray();
|
||||
@@ -135,7 +135,7 @@ CHEATSHEET C#
|
||||
|
||||
6.1 TimeSpan Constructor
|
||||
|
||||
TimeSpan(hour, minute, sec)
|
||||
TimpeSpan(hour, minute, sec)
|
||||
|
||||
TimeSpan timeS = new TimeSpan(10, 14, 50);
|
||||
TimeSpan timeS_Hours = TimeSpan.FromDays(3640);
|
||||
@@ -144,8 +144,8 @@ CHEATSHEET C#
|
||||
|
||||
Format item syntax: {index[,alignment][:format string]}
|
||||
index - Specifies element in list of values to which format is applied
|
||||
alignment - Indicates minimum width (in characters) to display value
|
||||
format string - Contains the code which specifies the format of the displayed value
|
||||
aligment - Indicates minimun width (in characters) to display value
|
||||
format string - Contains the code which specififes the format of the displayed value
|
||||
|
||||
7.1 Numeric
|
||||
|
||||
@@ -293,7 +293,7 @@ CHEATSHEET C#
|
||||
[access modifier] className (parameters) [:initializer]
|
||||
|
||||
initializer -base calls constructor in base class.
|
||||
this calls constructor within class.
|
||||
this calls constuctor within class.
|
||||
|
||||
public class nameClass : Initializer {
|
||||
public className(dataType param1 , dataType param2, ...) : base(param1, param2)
|
||||
@@ -313,8 +313,8 @@ CHEATSHEET C#
|
||||
abstract – must be implemented by subclass
|
||||
|
||||
Passing parameters:
|
||||
1. By default, parameters are passed by value
|
||||
2. Passing by reference: ref, in and out modifiers
|
||||
1. By default, parametres are passed by value
|
||||
2. Passing by reference: ref, in and out modifers
|
||||
|
||||
To pass a parameter by reference with the intent of changing the value, use the ref, or out keyword. To pass by reference with the intent of avoiding copying but not changing the value, use the in modifier
|
||||
|
||||
|
||||
@@ -524,14 +524,14 @@ Cyan='\033[0;36m' # Cyan
|
||||
White='\033[0;97m' # White
|
||||
|
||||
# Additional colors
|
||||
LGrey='\033[0;37m' # Light Gray
|
||||
LGrey='\033[0;37m' # Ligth Gray
|
||||
DGrey='\033[0;90m' # Dark Gray
|
||||
LRed='\033[0;91m' # Light Red
|
||||
LGreen='\033[0;92m' # Light Green
|
||||
LYellow='\033[0;93m'# Light Yellow
|
||||
LBlue='\033[0;94m' # Light Blue
|
||||
LRed='\033[0;91m' # Ligth Red
|
||||
LGreen='\033[0;92m' # Ligth Green
|
||||
LYellow='\033[0;93m'# Ligth Yellow
|
||||
LBlue='\033[0;94m' # Ligth Blue
|
||||
LPurple='\033[0;95m'# Light Purple
|
||||
LCyan='\033[0;96m' # Light Cyan
|
||||
LCyan='\033[0;96m' # Ligth Cyan
|
||||
|
||||
|
||||
# Bold
|
||||
|
||||
@@ -397,8 +397,8 @@ d, t := doubleAndTriple(5)
|
||||
_, t := doubleAndTriple(3)
|
||||
// t = 9
|
||||
|
||||
// Functions can defer commands. Deferred commands are
|
||||
// ran in a stack order after the execution and
|
||||
// Functions can defer commands. Defered commands are
|
||||
// runned in a stack order after the execution and
|
||||
// returning of a function
|
||||
var aux = 0
|
||||
|
||||
@@ -488,7 +488,7 @@ person3.Age // 0
|
||||
|
||||
## Maps
|
||||
|
||||
Maps are data structures that holds values assigned to a key.
|
||||
Maps are data structures that holds values assigneds to a key.
|
||||
|
||||
```go
|
||||
// Declaring a map
|
||||
@@ -508,7 +508,7 @@ newYork // "EUA"
|
||||
// Delete
|
||||
delete(cities, "NY")
|
||||
|
||||
// Check if a key is set
|
||||
// Check if a key is setted
|
||||
value, ok := cities["NY"]
|
||||
ok // false
|
||||
value // ""
|
||||
|
||||
@@ -308,7 +308,7 @@ for(dataType item : array) {
|
||||
//Declare a variable, object name
|
||||
String s;
|
||||
|
||||
//Invoke a constructor to create an object
|
||||
//Invoke a contructor to create an object
|
||||
s = new String ("Hello World");
|
||||
|
||||
//Invoke an instance method that operates on the object's value
|
||||
|
||||
@@ -95,9 +95,3 @@ arr.reduce(callback[, initialValue]) // Apply a function against
|
||||
arr.reduceRight(callback[, initialValue]) // Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value.
|
||||
arr.some(callback[, initialValue]) // Returns true if at least one element in this array satisfies the provided testing function.
|
||||
arr.values() // Returns a new Array Iterator object that contains the values for each index in the array.
|
||||
|
||||
// String methods
|
||||
String.charAt(index) // Returns the character at the specified index in a string.
|
||||
String.indexOf(character) // Returns the index of the first occurrence of a specified value in a string.
|
||||
String.substring(starting_index, ending_index) // Returns a new string that is a subset of the original string.
|
||||
String.substring(starting_index) // Returns a substring from starting index to last index of string.
|
||||
@@ -1,8 +1,8 @@
|
||||
<?php
|
||||
|
||||
// Exit the file, string inside get's echo'ed
|
||||
die("This file is not meant to be ran. ¯\_(ツ)_/¯");
|
||||
exit("This file is not meant to be ran. ¯\_(ツ)_/¯");
|
||||
die("This file is not ment to be ran. ¯\_(ツ)_/¯");
|
||||
exit("This file is not ment to be ran. ¯\_(ツ)_/¯");
|
||||
|
||||
/**
|
||||
* Printing
|
||||
@@ -17,7 +17,7 @@ var_dump($arr); // Print anything, with type hints for any value and sizes
|
||||
$string = 'Awesome cheatsheets';
|
||||
|
||||
str_contains($string, 'cheat'); // Find if the string contains the specified string (PHP >= 8.0)
|
||||
str_replace('Awesome', 'Bonjour', $string); // Replace all occurrence
|
||||
str_replace('Awesome', 'Bonjour', $string); // Replace all occurence
|
||||
strcmp($string, 'Awesome cheatsheets'); // Compare two strings
|
||||
strpos($string, 'a', 0); // Get position in the string
|
||||
str_split($string, 2); // Split the string
|
||||
@@ -541,7 +541,7 @@ u Pattern is treated as UTF-8
|
||||
\w Any "word" character (a-z 0-9 _)
|
||||
\W Any non "word" character
|
||||
\s Whitespace (space, tab CRLF)
|
||||
\S Any non whitespace character
|
||||
\S Any non whitepsace character
|
||||
\d Digits (0-9)
|
||||
\D Any non digit character
|
||||
. (Period) - Any character except newline
|
||||
|
||||
@@ -71,7 +71,7 @@
|
||||
| import | import libraries/modules/packages | import |
|
||||
| from | import specific function/classes from modules/packages | import |
|
||||
| try | this block will be tried to get executed | exception handling |
|
||||
| except | is any exception/error has occurred it'll be executed | exception handling |
|
||||
| except | is any exception/error has occured it'll be executed | exception handling |
|
||||
| finally | It'll be executed no matter exception occurs or not | exception handling |
|
||||
| raise | throws any specific error/exception | exception handling |
|
||||
| assert | throws an AssertionError if condition is false | exception handling |
|
||||
|
||||
@@ -21,7 +21,6 @@ cat /proc/<process_id>/maps # Show the current virtual memory usage of a Linux
|
||||
ip r # Display ip of the server
|
||||
|
||||
lsof -i :9000 # List process running on port 9000
|
||||
kill -9 $(lsof -t -i:PORT) # Kill the process running on whichever port specified
|
||||
|
||||
journalctl -u minio.service -n 100 --no-pager # List last 100 logs for specific service
|
||||
|
||||
|
||||
@@ -20,15 +20,13 @@ e jump to end of words (punctuation considered words)
|
||||
E jump to end of words (no punctuation)
|
||||
b jump backward by words (punctuation considered words)
|
||||
B jump backward by words (no punctuation)
|
||||
ge jump backward to end of a word
|
||||
gE jump backwards to the end of a word (words can contain punctuation)
|
||||
ge jump backward to end of words
|
||||
0 (zero) start of line
|
||||
^ first non-blank character of line
|
||||
$ jump to the end of the line
|
||||
g_ jump to the last non-blank character of the line
|
||||
- move line upwards, on the first non-blank character
|
||||
+ move line downwards, on the first non-blank character
|
||||
<enter> move line downwards, on the first non-blank character
|
||||
$ end of line
|
||||
- move line upwards, on the first non blank character
|
||||
+ move line downwards, on the first non blank character
|
||||
<enter> move line downwards, on the first non blank character
|
||||
gg go to first line
|
||||
G go to last line
|
||||
ngg go to line n
|
||||
@@ -40,6 +38,10 @@ nG go To line n
|
||||
} move the cursor a paragraph forwards
|
||||
]] move the cursor a section forwards or to the next {
|
||||
[[ move the cursor a section backwards or the previous {
|
||||
CTRL-f move the cursor forward by a screen of text
|
||||
CTRL-b move the cursor backward by a screen of text
|
||||
CTRL-u move the cursor up by half a screen
|
||||
CTRL-d move the cursor down by half a screen
|
||||
H move the cursor to the top of the screen.
|
||||
M move the cursor to the middle of the screen.
|
||||
L move the cursor to the bottom of the screen.
|
||||
@@ -47,16 +49,6 @@ fx search line forward for 'x'
|
||||
Fx search line backward for 'x'
|
||||
tx search line forward before 'x'
|
||||
Tx search line backward before 'x'
|
||||
CTRL-y moves screen up one line
|
||||
CTRL-e moves screen down one line
|
||||
CTRL-u moves cursor & screen up ½ page
|
||||
CTRL-d moves cursor & screen down ½ page
|
||||
CTRL-b moves screen up one page, cursor to last line
|
||||
CTRL-f moves screen down one page, cursor to first line
|
||||
zz shift current line to middle of screen
|
||||
z. same as zz but also jumps to the first non-black character
|
||||
zt shift current line to top of screen
|
||||
zb shift current line to bottom of screen
|
||||
|
||||
|
||||
##############################################################################
|
||||
@@ -68,15 +60,8 @@ zb shift current line to bottom of screen
|
||||
ma make a bookmark named a at the current cursor position
|
||||
`a go to position of bookmark a
|
||||
'a go to the line with bookmark a
|
||||
`0 go to the position where Vim was previously exited
|
||||
`" go to the position when last editing this file
|
||||
`. go to the line that you last edited
|
||||
`` go to the position before the last jump
|
||||
g, go to newer position in change list
|
||||
g; go to older position in change list
|
||||
|
||||
# Tip: To jump to a mark you can either use a backtick (`) or an apostrophe (').
|
||||
# Using an apostrophe jumps to the beginning (first non-blank) of the line holding the mark.
|
||||
|
||||
##############################################################################
|
||||
# INSERT MODE
|
||||
@@ -85,13 +70,10 @@ g; go to older position in change list
|
||||
|
||||
i start insert mode at cursor
|
||||
I insert at the beginning of the line
|
||||
gi return to insert mode where you inserted text the last time
|
||||
gI like "I", but always start in column 1
|
||||
a append after the cursor
|
||||
A append at the end of the line
|
||||
o open (append) blank line below current line
|
||||
O open blank line above current line
|
||||
CTRL-o Temporarily enter normal mode to issue one normal-mode command(while in insert mode)
|
||||
Esc exit insert mode
|
||||
|
||||
|
||||
@@ -102,25 +84,10 @@ Esc exit insert mode
|
||||
|
||||
r replace a single character (does not use insert mode)
|
||||
R enter Insert mode, replacing characters rather than inserting
|
||||
J join line below to the current one with one space in between
|
||||
gJ join line below to the current one without space in between
|
||||
J join line below to the current one
|
||||
cc change (replace) an entire line
|
||||
cw change (replace) to the end of word (same as ce)
|
||||
2cw change (replace) repeat cw twice
|
||||
ciw change (replace) word under the cursor
|
||||
caw change (replace) word under the cursor and the space after or before it
|
||||
ci" change (replace) word inside ""
|
||||
cit change (replace) html tag content
|
||||
cat change (replace) html tag
|
||||
cis change (replace) sentence under the cursor
|
||||
cas change (replace) sentence under the cursor and the space after or before it
|
||||
cib change (replace) inside a block with ()
|
||||
cab change (replace) a block with ()
|
||||
ciB change (replace) inside a block with {}
|
||||
caB change (replace) a block with {}
|
||||
C change (replace) to the end of line(same as c$)
|
||||
cG change (replace) to the end of the file
|
||||
cgg change (replace) from first line to current line
|
||||
cw change (replace) to the end of word
|
||||
C change (replace) to the end of line
|
||||
ct' change (replace) until the ' character (can change ' for any character)
|
||||
s delete character at cursor and substitute text
|
||||
S delete line at cursor and substitute text (same as cc)
|
||||
@@ -135,7 +102,6 @@ guiw make current word lowercase
|
||||
gU$ make uppercase until end of line
|
||||
gu$ make lowercase until end of line
|
||||
>> indent line one column to right
|
||||
>i{ indent everything in the {}
|
||||
<< indent line one column to left
|
||||
== auto-indent current line
|
||||
ddp swap current line with next
|
||||
@@ -144,7 +110,6 @@ ddkP swap current line with previous
|
||||
:r [name] insert the file [name] below the cursor.
|
||||
:r !{cmd} execute {cmd} and insert its standard output below the cursor.
|
||||
|
||||
# Tip: Instead of b or B one can also use ( or { respectively.
|
||||
|
||||
##############################################################################
|
||||
# DELETING TEXT
|
||||
@@ -153,15 +118,10 @@ ddkP swap current line with previous
|
||||
|
||||
x delete current character
|
||||
X delete previous character
|
||||
dw delete (cut) to the end of word (same as de)
|
||||
diw delete (cut) word under the cursor
|
||||
daw delete (cut) word under the cursor and the space after or before it
|
||||
dap delete (cut) a paragraph
|
||||
dw delete the current word
|
||||
dd delete (cut) a line
|
||||
dt' delete (cut) until the next ' character on the line (replace ' by any character)
|
||||
dG delete (cut) to the end of the file
|
||||
dgg delete (cut) from first line to current line
|
||||
D delete (cut) from cursor to end of line (same as d$)
|
||||
dt' delete until the next ' character on the line (replace ' by any character)
|
||||
D delete from cursor to end of line
|
||||
:[range]d delete [range] lines
|
||||
|
||||
|
||||
@@ -176,10 +136,6 @@ yy yank (copy) a line
|
||||
y$ yank to end of line
|
||||
p put (paste) the clipboard after cursor/current line
|
||||
P put (paste) before cursor/current line
|
||||
gp put (paste) the clipboard after cursor and leave cursor after the new text
|
||||
gP put (paste) before cursor and leave cursor after the new text
|
||||
"+y yank into the system clipboard register
|
||||
"+p paste from the system clipboard register
|
||||
:set paste avoid unexpected effects in pasting
|
||||
:registers display the contents of all registers
|
||||
"xyw yank word into register x
|
||||
@@ -191,12 +147,6 @@ gP put (paste) before cursor and leave cursor after the new tex
|
||||
"xgP just like "P", but leave the cursor just after the new text
|
||||
:[line]put x put the text from register x after [line]
|
||||
|
||||
# Tip: if you are using vim extension on vs code, you can enable
|
||||
"vim.useSystemClipboard": true
|
||||
in setting.json, this will allow to Use system clipboard for unnamed register.
|
||||
|
||||
|
||||
|
||||
|
||||
##############################################################################
|
||||
# MACROS
|
||||
@@ -207,7 +157,6 @@ qa start recording macro 'a'
|
||||
q end recording macro
|
||||
@a replay macro 'a'
|
||||
@: replay last command
|
||||
@@ repeat macro
|
||||
|
||||
|
||||
##############################################################################
|
||||
@@ -223,11 +172,9 @@ CTRL-v start visual block mode
|
||||
O move to other corner of block
|
||||
aw mark a word
|
||||
ab a () block (with braces)
|
||||
aB a {} block (with brackets)
|
||||
at a block with <> tags
|
||||
ab a {} block (with brackets)
|
||||
ib inner () block
|
||||
iB inner {} block
|
||||
it inner <> block
|
||||
ib inner {} block
|
||||
Esc exit visual mode
|
||||
|
||||
VISUAL MODE COMMANDS
|
||||
@@ -247,7 +194,6 @@ v% selects matching parenthesis
|
||||
vi{ selects matching curly brace
|
||||
vi" selects text between double quotes
|
||||
vi' selects text between single quotes
|
||||
gv reselect the last selected area
|
||||
|
||||
##############################################################################
|
||||
# SPELLING
|
||||
@@ -337,6 +283,7 @@ CTRL-w < increase window width
|
||||
CTRL-w > decrease window width
|
||||
CTRL-w = equal window
|
||||
CTRL-w o close other windows
|
||||
zz Centers the window to the current line
|
||||
|
||||
|
||||
##############################################################################
|
||||
@@ -359,14 +306,12 @@ clast display the last error
|
||||
|
||||
|
||||
% show matching brace, bracket, or parenthese
|
||||
gf edit the file whose name is under the cursor
|
||||
gF edit the file whose name is under the cursor and jump to the line number
|
||||
gf edit the file whose name is under or after the cursor
|
||||
gd when the cursor is on a local variable or function, jump to its declaration
|
||||
'' return to the line where the cursor was before the latest jump
|
||||
gi return to insert mode where you inserted text the last time
|
||||
CTRL-o move to previous position you were at
|
||||
CTRL-i move to more recent position you were at
|
||||
:set nu display numbers (short for :set number)
|
||||
:set nonu hide numbers (short for :set nonumber)
|
||||
|
||||
|
||||
##############################################################################
|
||||
|
||||
Reference in New Issue
Block a user