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SQL	Structured Query Language, used to work with databases		tech-sql-commands
Database	An organized collection of data		tech-sql-commands
Table	Rows and columns of data in a database		tech-sql-commands
Row (record)	One entry in a table		tech-sql-commands
Column (field)	One attribute shared by all rows		tech-sql-commands
Primary key	A column that uniquely identifies each row		tech-sql-commands
Foreign key	A column linking to the primary key of another table		tech-sql-commands
SELECT	Gets data from a table		tech-sql-commands
SELECT *	Gets every column		tech-sql-commands
FROM	Names the table to read		tech-sql-commands
WHERE	Filters rows by a condition		tech-sql-commands
AND, OR, NOT	Combine or negate conditions		tech-sql-commands
ORDER BY	Sorts the results		tech-sql-commands
ASC / DESC	Sort ascending or descending		tech-sql-commands
LIMIT	Restricts how many rows are returned		tech-sql-commands
DISTINCT	Removes duplicate values from results		tech-sql-commands
LIKE	Matches text patterns		tech-sql-commands
% wildcard	Matches any number of characters in LIKE		tech-sql-commands
_ wildcard	Matches exactly one character in LIKE		tech-sql-commands
IN	Matches any value in a list		tech-sql-commands
BETWEEN	Matches a range of values		tech-sql-commands
IS NULL	Tests for missing values		tech-sql-commands
AS (alias)	Gives a column or table a temporary name		tech-sql-commands
INSERT INTO	Adds new rows to a table		tech-sql-commands
VALUES	Gives the values for an insert		tech-sql-commands
UPDATE	Changes data in existing rows		tech-sql-commands
SET	Names the columns to change in an update		tech-sql-commands
DELETE FROM	Removes rows		tech-sql-commands
CREATE TABLE	Makes a new table		tech-sql-commands
ALTER TABLE	Changes a table's structure		tech-sql-commands
DROP TABLE	Deletes a table entirely		tech-sql-commands
CREATE INDEX	Makes a table lookup faster		tech-sql-commands
COUNT()	Counts rows		tech-sql-commands
SUM()	Adds up values		tech-sql-commands
AVG()	Finds the average		tech-sql-commands
MIN()	Finds the smallest value		tech-sql-commands
MAX()	Finds the largest value		tech-sql-commands
GROUP BY	Groups rows to use with aggregate functions		tech-sql-commands
HAVING	Filters groups after grouping		tech-sql-commands
JOIN	Combines rows from two tables		tech-sql-commands
INNER JOIN	Keeps only rows that match in both tables		tech-sql-commands
LEFT JOIN	Keeps all rows from the left table and matches from the right		tech-sql-commands
RIGHT JOIN	Keeps all rows from the right table and matches from the left		tech-sql-commands
FULL OUTER JOIN	Keeps all rows from both tables		tech-sql-commands
CROSS JOIN	Pairs every row of one table with every row of another		tech-sql-commands
UNION	Combines results of two queries, removing duplicates		tech-sql-commands
UNION ALL	Combines results and keeps duplicates		tech-sql-commands
Subquery	A query inside another query		tech-sql-commands
EXISTS	Tests whether a subquery returns rows		tech-sql-commands
CASE WHEN	Conditional logic inside a query		tech-sql-commands
NULL	A missing or unknown value		tech-sql-commands
NOT NULL	A column must always have a value		tech-sql-commands
UNIQUE	All values in a column must be different		tech-sql-commands
DEFAULT	A value used when none is given		tech-sql-commands
CHECK	A rule that values must satisfy		tech-sql-commands
Transaction	A group of operations that succeed or fail together		tech-sql-commands
COMMIT	Saves a transaction		tech-sql-commands
ROLLBACK	Undoes a transaction		tech-sql-commands
View	A saved query that acts like a table		tech-sql-commands
Index	A structure that speeds up searches		tech-sql-commands
Normalization	Organizing tables to reduce repeated data		tech-sql-commands
Schema	The structure of a database		tech-sql-commands
Relational database	A database storing data in related tables		tech-sql-commands
One-to-many relationship	One row in a table relates to many rows in another		tech-sql-commands
Many-to-many relationship	Many rows relate to many, using a join table		tech-sql-commands
ACID	Atomicity, Consistency, Isolation, Durability, properties of reliable transactions		tech-sql-commands
SQL injection	An attack that sneaks harmful SQL into input; prevent with parameterized queries		tech-sql-commands
Parameterized query	A query with placeholders for safe user input		tech-sql-commands
MySQL, PostgreSQL, SQLite	Popular SQL database systems		tech-sql-commands
NoSQL	Databases that don't use traditional tables, like document stores		tech-sql-commands
Query	A request for data		tech-sql-commands
CRUD	Create, Read, Update, Delete		tech-sql-commands