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SQL

Exempel på SQL Exempel på SQL och hur man använder sub-queries

Subqueries

SELECT firstname FROM persons WHERE salary > (SELECT AVG(salary) FROM persons WHERE gender = 'M')

Sql är ett frågespråk...

Förkortningar

  • SQL - Structured Query Language

  • PSQL - Postgre SQL
  • SSMS - SQL Server Management Studio
  • SSDT - SQL Server Data Tools

Filändelser

  • .sql
SQLite logotyp Microsoft SQL Server logotyp Logotyp för MySQL Logotyp för PostgreSQL

Typer

Logotyp för Sequel pro

Program

Kommentarer

-- En kommentar

Kommandon

  • SELECT
  • INSERT
  • UPDATE
  • REPLACE
  • DELETE

  • JOIN

  • INTO OUTFILE
  • FIELDS TERMINATED BY
  • ENCLOSED BY
  • LINES TERMINATED BY

Nyckel i SQL

PRIMARY KEY

Variabel i SQL

DECLARE @variabel INT SET @variabel=1

Loop i SQL

WHILE condition BEGIN … END

Funktion för att söka efter en tagg i SQL

FIND_IN_SET(key, haystack)

Operatorer

Operator Beskrivning
= Equal
<=> Equal (Safe to compare NULL values)
<> Not Equal
!= Not Equal
> Greater Than
>= Greater Than or Equal
< Less Than
<= Less Than or Equal
IN ( ) Matches a value in a list
NOT Negates a condition
BETWEEN Within a range (inclusive)
IS NULL NULL value
IS NOT NULL Non-NULL value
LIKE Pattern matching with % and _
EXISTS Condition is met if subquery returns at least one row

Reserverade ord, variabler och funktioner i MySQL (5.0.96)

Visa alla
  • ADD
  • ALL
  • ALTER
  • ANALYZE
  • AND
  • ASASC
  • ASENSITIVE
  • BEFORE
  • BETWEEN
  • BIGINT
  • BINARY
  • BLOB
  • BOTH
  • BY
  • CALL
  • CASCADE
  • CASE
  • CHANGE
  • CHAR
  • CHARACTER
  • CHECK
  • COLLATE
  • COLUMN
  • CONDITION
  • CONSTRAINT
  • CONTINUE
  • CONVERT
  • CREATE
  • CROSS
  • CURRENT_DATE
  • CURRENT_TIME
  • CURRENT_TIMESTAMPCURRENT_USERCURSOR
  • DATABASE
  • DATABASES
  • DAY_HOUR
  • DAY_MICROSECONDDAY_MINUTE
  • DAY_SECONDDEC
  • DECIMAL
  • DECLARE
  • DEFAULT
  • DELAYED
  • DELETE
  • DESC
  • DESCRIBE
  • DETERMINISTIC
  • DISTINCT
  • DISTINCTROW
  • DIV
  • DOUBLE
  • DROP
  • DUAL
  • EACH
  • ELSE
  • ELSEIF
  • ENCLOSED
  • ESCAPED
  • EXISTS
  • EXIT
  • EXPLAIN
  • FALSE
  • FETCH
  • FLOAT
  • FLOAT4
  • FLOAT8
  • FOR
  • FORCE
  • FOREIGN
  • FROM
  • FULLTEXT
  • GRANT
  • GROUP
  • HAVING
  • HIGH_PRIORITYHOUR_MICROSECOND
  • HOUR_MINUTE
  • HOUR_SECONDIF
  • IGNORE
  • IN
  • INDEX
  • INFILE
  • INNER
  • INOUT
  • INSENSITIVE
  • INSERT
  • INT
  • INT1
  • INT2
  • INT3
  • INT4
  • INT8
  • INTEGER
  • INTERVAL
  • INTO
  • IS
  • ITERATE
  • JOIN
  • KEY
  • KEYS
  • KILL
  • LEADING
  • LEAVE
  • LEFT
  • LIKE
  • LIMIT
  • LINES
  • LOAD
  • LOCALTIME
  • LOCALTIMESTAMP
  • LOCK
  • LONG
  • LONGBLOB
  • LONGTEXT
  • LOOP
  • LOW_PRIORITYMATCH
  • MEDIUMBLOB
  • MEDIUMINT
  • MEDIUMTEXT
  • MIDDLEINT
  • MINUTE_MICROSECONDMINUTE_SECONDMOD
  • MODIFIES
  • NATURAL
  • NOT
  • NO_WRITE_TO_BINLOGNULL
  • NUMERIC
  • ON
  • OPTIMIZE
  • OPTION
  • OPTIONALLY
  • OR
  • ORDER
  • OUT
  • OUTER
  • OUTFILE
  • PRECISION
  • PRIMARY
  • PROCEDURE
  • PURGE
  • READ
  • READS
  • REAL
  • REFERENCES
  • REGEXP
  • RELEASE
  • RENAME
  • REPEAT
  • REPLACE
  • REQUIRE
  • RESTRICT
  • RETURN
  • REVOKE
  • RIGHT
  • RLIKE
  • SCHEMA
  • SCHEMAS
  • SECOND_MICROSECONDSELECT
  • SENSITIVE
  • SEPARATOR
  • SET
  • SHOW
  • SMALLINT
  • SONAME
  • SPATIAL
  • SPECIFIC
  • SQL
  • SQLEXCEPTION
  • SQLSTATE
  • SQLWARNING
  • SQL_BIG_RESULT
  • SQL_CALC_FOUND_ROWSSQL_SMALL_RESULTSSL
  • STARTING
  • STRAIGHT_JOINTABLE
  • TERMINATED
  • THEN
  • TINYBLOB
  • TINYINT
  • TINYTEXT
  • TO
  • TRAILING
  • TRIGGER
  • TRUE
  • UNDO
  • UNION
  • UNIQUE
  • UNLOCK
  • UNSIGNED
  • UPDATE
  • USAGE
  • USE
  • USING
  • UTC_DATEUTC_TIME
  • UTC_TIMESTAMPVALUES
  • VARBINARY
  • VARCHAR
  • VARCHARACTER
  • VARYING
  • WHEN
  • WHERE
  • WHILE
  • WITH
  • WRITE
  • XOR
  • YEAR_MONTHZEROFILL

Version av SQL

sql --version

Vilken SQL?

which sql

Sökväg

? Skiss av databas

Länkar

Namn

  • Maria
  • My

Motsats

  • NoSQL
Logotyp för MySQL

Liknande

GraphQL logotyp

Liknande namn

Kuriosa

Externa länkar