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December 28, 2022 08:00 pm GMT

Here is a cheatsheet for SQL:

SELECT - used to retrieve data from a database

SELECT column1, column2, ...FROM table_nameWHERE condition;

INSERT INTO - used to insert new rows into a table

INSERT INTO table_name (column1, column2, ...)VALUES (value1, value2, ...);

UPDATE - used to modify existing rows in a table

UPDATE table_nameSET column1 = value1, column2 = value2, ...WHERE condition;

DELETE FROM - used to delete existing rows from a table

DELETE FROM table_nameWHERE condition;

CREATE TABLE - used to create a new table

CREATE TABLE table_name (    column1 datatype constraint,    column2 datatype constraint,    ...);

ALTER TABLE - used to modify an existing table

ALTER TABLE table_nameADD column datatype constraint;ALTER TABLE table_nameDROP COLUMN column;

TRUNCATE TABLE - used to delete all data from a table

TRUNCATE TABLE table_name;

JOIN - used to combine rows from multiple tables

SELECT column1, column2, ...FROM table1JOIN table2ON table1.column = table2.column;

UNION - used to combine the result sets of two or more SELECT statements

SELECT column1, column2, ...FROM table1UNIONSELECT column1, column2, ...FROM table2;

GROUP BY - used to group together rows that have the same values in one or more columns

SELECT column1, SUM(column2)FROM table_nameGROUP BY column1;

HAVING - used to filter the results of a GROUP BY clause

SELECT column1, SUM(column2)FROM table_nameGROUP BY column1HAVING SUM(column2) > value;

LIMIT - used to limit the number of rows returned in a SELECT statement

SELECT column1, column2, ...FROM table_nameLIMIT number;

ORDER BY - used to sort the result set of a SELECT statement

SELECT column1, column2, ...FROM table_nameORDER BY column1 ASC/DESC;

BETWEEN - used to select values within a specific range

SELECT column1, column2, ...FROM table_nameWHERE column1 BETWEEN value1 AND value2;

LIKE - used to search for a specific pattern in a column

SELECT column1, column2, ...FROM table_nameWHERE column1 LIKE pattern;

IN - used to specify a list of values to compare against

SELECT column1, column2, ...FROM table_nameWHERE column1 IN (value1, value2, ...);

IS NULL - used to test for NULL values

SELECT column1, column2, ...FROM table_nameWHERE column1 IS NULL;

EXISTS - used to test for the existence of rows in a subquery

SELECT column1, column2, ...FROM table_nameWHERE EXISTS (SELECT * FROM table_name WHERE condition);

COUNT - used to return the number of rows in a SELECT statement

SELECT COUNT(*)FROM table_name;

SUM - used to return the sum of the values in a specific column

SELECT SUM(column)FROM table_name;

AVG - used to return the average value of a specific column

SELECT AVG(column)FROM table_name;

MIN - used to return the minimum value in a specific column

SELECT MIN(column)FROM table_name;

MAX - used to return the maximum value in a specific column

SELECT MAX(column)FROM table_name;

DISTINCT - used to return unique values in the output

SELECT DISTINCT column1, column2, ...FROM table_name;

AS - used to specify an alias for a column or table

SELECT column1 AS 'alias'FROM table_name;SELECT t1.column1, t2.column2FROM table1 AS t1JOIN table2 AS t2ON t1.column = t2.column;

CASE - used to create conditional statements within a SELECT statement

SELECT column1,    (CASE        WHEN column2 > value THEN 'A'        WHEN column2 = value THEN 'B'        ELSE 'C'    END) AS 'alias'FROM table_name;

COALESCE - used to return the first non-NULL value in a list of values

SELECT COALESCE(column1, column2, ...)FROM table_name;

NULLIF - used to return NULL if two expressions are equal

SELECT NULLIF(expression1, expression2)FROM table_name;

IFNULL - used to return a specified value if an expression is NULL

SELECT IFNULL(expression, value)FROM table_name;

DATE_ADD - used to add a specified time interval to a date

SELECT DATE_ADD(date, INTERVAL value unit)FROM table_name;

DATE_SUB - used to subtract a specified time interval from a date

SELECT DATE_SUB(date, INTERVAL value unit)FROM table_name;

DATE_FORMAT - used to format a date in a specific way

SELECT DATE_FORMAT(date, 'format')FROM table_name;

CONCAT - used to concatenate two or more strings

SELECT CONCAT(string1, string2, ...)FROM table_name;

Original Link: https://dev.to/arafat4693/sql-cheat-sheet-6j2

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