sql_cheatsheet.md

SQL database commands:

SELECT: Retrieve data from a table.

SELECT column1, column2 FROM table_name;

DISTINCT: Select unique values from a column.

SELECT DISTINCT column_name FROM table_name;

WHERE: Filter rows based on a condition.

SELECT column1, column2 FROM table_name WHERE condition;

AND/OR: Combine multiple conditions in a WHERE clause.

SELECT column1, column2 FROM table_name WHERE condition1 AND condition2;

ORDER BY: Sort the result set.

SELECT column1, column2 FROM table_name ORDER BY column1 ASC;

LIMIT: Limit the number of rows returned.

SELECT column1, column2 FROM table_name LIMIT 10;

INSERT INTO: Insert new rows into a table.

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

UPDATE: Modify existing data in a table.

UPDATE table_name SET column1 = value1 WHERE condition;

DELETE: Delete rows from a table.

DELETE FROM table_name WHERE condition;

CREATE TABLE: Create a new table.

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

ALTER TABLE: Modify an existing table.

ALTER TABLE table_name ADD column_name datatype;

DROP TABLE: Delete a table.

DROP TABLE table_name;

JOIN: Combine rows from multiple tables based on a related column.

SELECT column1, column2 FROM table1 JOIN table2 ON table1.column = table2.column;

GROUP BY: Group rows based on a column.

SELECT column1, COUNT(column2) FROM table_name GROUP BY column1;

HAVING: Filter groups based on a condition.

SELECT column1, COUNT(column2) FROM table_name GROUP BY column1 HAVING COUNT(column2) > 5;

NULL: Represents a missing or unknown value.

SELECT column1 FROM table_name WHERE column2 IS NULL;

INDEX: Create an index for faster data retrieval.

CREATE INDEX index_name ON table_name (column_name);