MySQL Cheat Sheet
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The document is a MySQL cheat sheet that outlines various data types such as strings, integers, and dates, along with their respective ranges. It provides essential SQL commands for selecting, creating, modifying, and deleting databases and tables, as well as performing joins and string functions. Additionally, it includes information on aggregate functions and the creation of tables with auto-incrementing keys.
![MySQL Cheat Sheet
MySQL Data Types
CHAR String (0 - 255)
VARCHAR String (0 - 255)
TINYTEXT String (0 - 255)
TEXT String (0 - 65535)
BLOB String (0 - 65535)
MEDIUMTEXT String (0 - 16777215)
MEDIUMBLOB String (0 - 16777215)
LONGTEXT String (0 - 4294967295)
LONGBLOB String (0 - 4294967295)
TINYINT x Integer (-128 to 127)
SMALLINT x Integer (-32768 to 32767)
MEDIUMINT x Integer (-8388608 to 8388607)
INT x Integer (-2147483648 to
2147483647)
BIGINT x Integer
(-9223372036854775808 to
9223372036854775807)
FLOAT Decimal (precise to 23 digits)
DOUBLE Decimal (24 to 53 digits)
DECIMAL "DOUBLE" stored as string
DATE YYYY-MM-DD
DATETIME YYYY-MM-DD HH:MM:SS
TIMESTAMP YYYYMMDDHHMMSS
TIME HH:MM:SS
ENUM One of preset options
SET Selection of preset options
Integers (marked x) that are "UNSIGNED" have the
same range of values but start from 0 (i.e., an
UNSIGNED TINYINT can have any value from 0 to
255).
Select queries
select all columns
SELECT * FROM tbl;
select some columns
SELECT col1, col2 FROM tbl;
select only unique records
SELECT DISTINCT FROM tbl WHERE
condition;
column alias with AS
SELECT col FROM tbl AS newname;
order results
SELECT * FROM tbl ORDER BY col [ASC |
DESC];
group results
SELECT col1, SUM(col2) FROM tbl GROUP BY
col1;
Creating and modifying
create a database
CREATE DATABASE db_name;
select a database
USE db_name;
list the databases on the server
SHOW DATABASES;
show a table's fields
DESCRIBE tbl;
create a new table
CREATE TABLE tbl (field1, field2);
insert data into a table
INSERT INTO tbl VALUES ("val1", "val2");
delete a row
DELETE * FROM tbl WHERE condition;
add a column from a table
ALTER TABLE tbl ADD COLUMN col;
remove a column from a table
ALTER TABLE tbl DROP COLUMN col;
make a column a primary key
ALTER TABLE tbl ADD PRIMARY KEY (col);
return only 1 row matching query
... LIMIT = 1
amend the values of a column
UPDATE table SET column1="val1" WHERE ...
clear all the values, leaving the table structure
TRUNCATE TABLE tbl;
delete the table
DROP TABLE tbl;
delete the database
DROP DATABASE db_name;
Matching data
matching data using LIKE
SELECT * FROM tbl1 WHERE col LIKE
‘%value%’
matching data using REGEX
SELECT * FROM tbl1 WHERE col RLIKE
‘regular_expression’
Joins
INNER
JOIN
returns only where match in both
tables
OUTER
JOIN
also returns non-matching records
from both tables
LEFT
JOIN
also returns non-matching records
from left table
RIGHT
JOIN
also returns non-matching records in
right table
JOIN syntax:
SELECT * FROM tbl1 INNER JOIN tbl2 ON tbl1.id
= tbl2.id;
String functions MySQL
Compare
strings
STRCMP("str1","str2")
Convert to
lower case
LOWER("str")
Convert to
upper case
UPPER("str")
Left trim LTRIM("str")
Substring of a
string
SUBSTRING("str","inx1","inx2")
Concatenate CONCAT("str1","str2")
MySQL calculation functions
Count rows COUNT(col)
Average AVG(col)
Minimum value MIN(col)
Maximum value MAX(col)
Sum of values SUM(col)
Create table with auto-incrementing primary key
CREATE TABLE table_name (
id INT AUTO_INCREMENT,
column VARCHAR(2),
column VARCHAR(32),
PRIMARY KEY (id)
);
Updated by Saeid Zebardast
Twitter: @saeid
Email: saeid.zebardast@gmail.com
Home: http://zebardast.ir
About: http://about.me/saeid
Source: http://cheatography.com/guslong](https://image.slidesharecdn.com/pgegd5kqkerdhxv1k9rg-signature-fd6d5730ec02f85f4d2799a60336af8273582a48cc77d2c81c10bb7f353f1ff1-poli-141213093313-conversion-gate01/85/MySQL-Cheat-Sheet-1-320.jpg)
MySQL Cheat Sheet
- 1. MySQL Cheat Sheet MySQL Data Types CHAR String (0 - 255) VARCHAR String (0 - 255) TINYTEXT String (0 - 255) TEXT String (0 - 65535) BLOB String (0 - 65535) MEDIUMTEXT String (0 - 16777215) MEDIUMBLOB String (0 - 16777215) LONGTEXT String (0 - 4294967295) LONGBLOB String (0 - 4294967295) TINYINT x Integer (-128 to 127) SMALLINT x Integer (-32768 to 32767) MEDIUMINT x Integer (-8388608 to 8388607) INT x Integer (-2147483648 to 2147483647) BIGINT x Integer (-9223372036854775808 to 9223372036854775807) FLOAT Decimal (precise to 23 digits) DOUBLE Decimal (24 to 53 digits) DECIMAL "DOUBLE" stored as string DATE YYYY-MM-DD DATETIME YYYY-MM-DD HH:MM:SS TIMESTAMP YYYYMMDDHHMMSS TIME HH:MM:SS ENUM One of preset options SET Selection of preset options Integers (marked x) that are "UNSIGNED" have the same range of values but start from 0 (i.e., an UNSIGNED TINYINT can have any value from 0 to 255). Select queries select all columns SELECT * FROM tbl; select some columns SELECT col1, col2 FROM tbl; select only unique records SELECT DISTINCT FROM tbl WHERE condition; column alias with AS SELECT col FROM tbl AS newname; order results SELECT * FROM tbl ORDER BY col [ASC | DESC]; group results SELECT col1, SUM(col2) FROM tbl GROUP BY col1; Creating and modifying create a database CREATE DATABASE db_name; select a database USE db_name; list the databases on the server SHOW DATABASES; show a table's fields DESCRIBE tbl; create a new table CREATE TABLE tbl (field1, field2); insert data into a table INSERT INTO tbl VALUES ("val1", "val2"); delete a row DELETE * FROM tbl WHERE condition; add a column from a table ALTER TABLE tbl ADD COLUMN col; remove a column from a table ALTER TABLE tbl DROP COLUMN col; make a column a primary key ALTER TABLE tbl ADD PRIMARY KEY (col); return only 1 row matching query ... LIMIT = 1 amend the values of a column UPDATE table SET column1="val1" WHERE ... clear all the values, leaving the table structure TRUNCATE TABLE tbl; delete the table DROP TABLE tbl; delete the database DROP DATABASE db_name; Matching data matching data using LIKE SELECT * FROM tbl1 WHERE col LIKE ‘%value%’ matching data using REGEX SELECT * FROM tbl1 WHERE col RLIKE ‘regular_expression’ Joins INNER JOIN returns only where match in both tables OUTER JOIN also returns non-matching records from both tables LEFT JOIN also returns non-matching records from left table RIGHT JOIN also returns non-matching records in right table JOIN syntax: SELECT * FROM tbl1 INNER JOIN tbl2 ON tbl1.id = tbl2.id; String functions MySQL Compare strings STRCMP("str1","str2") Convert to lower case LOWER("str") Convert to upper case UPPER("str") Left trim LTRIM("str") Substring of a string SUBSTRING("str","inx1","inx2") Concatenate CONCAT("str1","str2") MySQL calculation functions Count rows COUNT(col) Average AVG(col) Minimum value MIN(col) Maximum value MAX(col) Sum of values SUM(col) Create table with auto-incrementing primary key CREATE TABLE table_name ( id INT AUTO_INCREMENT, column VARCHAR(2), column VARCHAR(32), PRIMARY KEY (id) ); Updated by Saeid Zebardast Twitter: @saeid Email: [email protected] Home: http://zebardast.ir About: http://about.me/saeid Source: http://cheatography.com/guslong