SQL Flashcards

SELECT

SELECT

Extracts data from a database

UPDATE

Modifies existing records in a table

DELETE

Removes existing records in a table

INSERT INTO

Adds new data into a database

CREATE DATABASE

Establishes a new database

ALTER DATABASE

Adjusts a database

CREATE TABLE

Generates a new table

ALTER TABLE

Modifies a table

DROP TABLE

Deletes a table

CREATE INDEX

Establishes an index (search key)

DROP INDEX

Removes an index

SELECT DISTINCT

Returns distinctly different values

COUNT()

Provides a count of data

WHERE

Sets criteria to filter data

=

Represents equal in SQL

>

Denotes greater than

<

Denotes less than

>=

Denotes greater than or equal to

<=

Denotes less than or equal to

<>

Denotes not equal

BETWEEN

Specifies a range

LIKE

Searches for a pattern

IN

Specifies multiple possible values for a column

ORDER BY

Sorts data in ascending or descending order

AND

Filters records based on multiple conditions

OR

Filters records based on any of the conditions

NOT

Negates a condition

NULL

Represents a field with no value

IS NULL

Checks for NULL values

IS NOT NULL

Checks for non-NULL values

SET

Modifies existing records in a table

MIN()

Returns the smallest value in a column

MAX()

Returns the largest value in a column

SUM()

Calculates the total sum of a numerical column

AVG()

Computes the average value of a numerical column

JOIN

Combines rows from two or more tables based on a related column

SELF JOIN

Joins a table to itself

UNION

Combines the result-set of multiple SELECT statements

ALL

Compares a value with every value in a subquery

AND

Combines conditions where all must be true

ANY

Compares a value with any value in a subquery

BETWEEN

Checks if an operand is within a range

EXISTS

Checks if a subquery returns records

IN

Checks if an operand is in a list of expressions

LIKE

Matches a pattern

NOT

Negates a condition

OR

Combines conditions where at least one must be true

SOME

Compares a value with some values in a subquery

+=

Adds and assigns

-=

Subtracts and assigns

*=

Multiplies and assigns

/=

Divides and assigns

%=

Modulo and assigns

&

Bitwise AND

|

Bitwise OR

^

Bitwise exclusive OR

+

Addition

-

Subtraction

*

Multiplication

/

Division

%

Modulo

ALTER TABLE

Adds, deletes, or modifies columns in a table