Reference

SQL Reserved Keywords

Complete SQL keyword reference organized by purpose. If your table or column name matches a reserved keyword, quote it ("name" in PostgreSQL, `name` in MySQL, [name] in SQL Server) to avoid syntax errors. Format queries with the SQL Formatter.

Data Query (DQL)

Keyword	Description
SELECT	Retrieve rows from one or more tables
FROM	Specify the source table(s)
WHERE	Filter rows by condition
GROUP BY	Group rows sharing a column value
HAVING	Filter groups after aggregation
ORDER BY	Sort results by column(s)
LIMIT	Restrict number of rows returned (MySQL, PostgreSQL, SQLite)
OFFSET	Skip rows before returning results
FETCH	Restrict rows (SQL standard, SQL Server)
DISTINCT	Remove duplicate rows from results
ALL	Include duplicates (default)
TOP	Restrict number of rows (SQL Server)
UNION	Combine results of two queries (deduplicated)
UNION ALL	Combine results of two queries (with duplicates)
INTERSECT	Rows present in both queries
EXCEPT	Rows in first query but not second (MINUS in Oracle)

Joins

Keyword	Description
JOIN	Combine rows from two tables
INNER JOIN	Rows matching in both tables
LEFT JOIN	All left rows, matched right rows (NULLs for no match)
RIGHT JOIN	All right rows, matched left rows
FULL OUTER JOIN	All rows from both tables
CROSS JOIN	Cartesian product of both tables
NATURAL JOIN	Join on columns with the same name
ON	Specify the join condition
USING	Join on a shared column name

Data Manipulation (DML)

Keyword	Description
INSERT INTO	Add new rows to a table
VALUES	Specify literal row data for INSERT
UPDATE	Modify existing rows
SET	Assign new column values in UPDATE
DELETE	Remove rows from a table
MERGE	Insert, update, or delete in a single statement (UPSERT)
REPLACE	Insert or replace existing row (MySQL)
TRUNCATE	Remove all rows (faster than DELETE, no rollback)
RETURNING	Return affected rows (PostgreSQL, SQLite 3.35+)

Data Definition (DDL)

Keyword	Description
CREATE	Create a database object (TABLE, INDEX, VIEW, etc.)
ALTER	Modify an existing object
DROP	Remove an object permanently
TABLE	A structured set of rows and columns
VIEW	A named query stored as a virtual table
INDEX	A data structure to speed lookups
SEQUENCE	An auto-incrementing number generator
SCHEMA	A namespace for database objects
DATABASE	A collection of schemas and objects
COLUMN	A field in a table
ADD	Add a column or constraint (ALTER TABLE)
RENAME	Rename a table or column
IF EXISTS	Avoid error if object is missing (DROP)
IF NOT EXISTS	Avoid error if object already exists (CREATE)
TEMPORARY	Create a session-scoped table

Constraints

Keyword	Description
PRIMARY KEY	Uniquely identify each row
FOREIGN KEY	Reference a row in another table
REFERENCES	Specify the target of a foreign key
UNIQUE	Prevent duplicate values in a column
NOT NULL	Disallow NULL values
CHECK	Enforce a boolean expression on column values
DEFAULT	Provide a fallback value when none is given
CONSTRAINT	Name a table constraint explicitly
AUTO_INCREMENT	Auto-generate sequential IDs (MySQL)
SERIAL	Auto-incrementing integer column (PostgreSQL)
AUTOINCREMENT	Strict auto-increment (SQLite)
IDENTITY	Auto-incrementing column (SQL Server, SQL standard)
CASCADE	Propagate deletes/updates to child rows
RESTRICT	Prevent delete/update if child rows exist

Operators & Predicates

Keyword	Description
AND	Logical AND
OR	Logical OR
NOT	Logical negation
IN	Match any value in a list or subquery
BETWEEN	Match a range (inclusive)
LIKE	Pattern match with % and _ wildcards
ILIKE	Case-insensitive LIKE (PostgreSQL)
IS NULL	Test for NULL
IS NOT NULL	Test for non-NULL
EXISTS	True if subquery returns any row
ANY	Compare to any value from a subquery
SOME	Synonym for ANY
CASE	Conditional expression (CASE WHEN ... THEN ... ELSE ... END)
WHEN	Branch inside a CASE expression
THEN	Result for a CASE WHEN branch
ELSE	Default CASE result
END	Close a CASE or BEGIN block
AS	Alias a column or table
CAST	Convert a value to a different type
COALESCE	Return first non-NULL argument
NULLIF	Return NULL if two values are equal

Aggregate Functions

Keyword	Description
COUNT	Number of rows
SUM	Total of numeric values
AVG	Average of numeric values
MIN	Smallest value
MAX	Largest value
STRING_AGG	Concatenate strings with delimiter (PostgreSQL, SQL Server)
GROUP_CONCAT	Concatenate strings (MySQL, SQLite)
ARRAY_AGG	Collect values into an array (PostgreSQL)

Window Functions

Keyword	Description
OVER	Define a window for the function
PARTITION BY	Divide rows into groups within a window
ROW_NUMBER	Sequential integer per partition
RANK	Rank with gaps on ties
DENSE_RANK	Rank without gaps on ties
NTILE	Distribute rows into N buckets
LAG	Value from a previous row
LEAD	Value from a following row
FIRST_VALUE	First value in the window frame
LAST_VALUE	Last value in the window frame
ROWS	Physical row-based window frame
RANGE	Logical value-based window frame

Transaction Control

Keyword	Description
BEGIN	Start a transaction
COMMIT	Save all changes since BEGIN
ROLLBACK	Undo all changes since BEGIN
SAVEPOINT	Create a named restore point
RELEASE	Remove a savepoint
LOCK	Acquire a table or row lock

Access Control (DCL)

Keyword	Description
GRANT	Give permissions to a user or role
REVOKE	Remove permissions from a user or role
ROLE	A named set of permissions
USER	A database account

Common Table Expressions & Subqueries

Keyword	Description
WITH	Define a Common Table Expression (CTE)
RECURSIVE	Allow a CTE to reference itself
LATERAL	Subquery that references preceding FROM items (PostgreSQL)

Data Types (cross-database)

Keyword	Description
INTEGER	Whole number (INT is a common alias)
BIGINT	64-bit integer
SMALLINT	16-bit integer
DECIMAL	Exact fixed-point number (NUMERIC is equivalent)
FLOAT	Approximate floating-point number
DOUBLE PRECISION	64-bit floating-point
BOOLEAN	True or false
VARCHAR	Variable-length string
CHAR	Fixed-length string
TEXT	Unlimited-length string
DATE	Calendar date (year, month, day)
TIME	Time of day
TIMESTAMP	Date and time
INTERVAL	Time span
BLOB	Binary large object
JSON	JSON data (MySQL, PostgreSQL)
JSONB	Binary JSON with indexing (PostgreSQL)
UUID	Universally unique identifier (PostgreSQL)
ARRAY	Array of values (PostgreSQL)

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