Denne artikel viser SQL'en SELECT
syntaks, som implementeret af forskellige databasestyringssystemer (DBMS'er). Syntaksen er angivet nøjagtigt som hver leverandør har angivet den på deres hjemmeside. Klik på det relevante link for at se flere detaljer om syntaksen for en bestemt leverandør.
De dækkede DBMS'er er MySQL, SQL Server, PostgreSQL og Oracle Database.
MySQL
Fra MySQL 5.7 Reference Manual:
SELECT [ALL | DISTINCT | DISTINCTROW ] [HIGH_PRIORITY] [MAX_STATEMENT_TIME =N
] [STRAIGHT_JOIN] [SQL_SMALL_RESULT] [SQL_BIG_RESULT] [SQL_BUFFER_RESULT] [SQL_CACHE | SQL_NO_CACHE] [SQL_CALC_FOUND_ROWS]select_expr
[,select_expr
...] [FROMtable_references
[PARTITIONpartition_list
] [WHEREwhere_condition
] [GROUP BY {col_name
|expr
|position
} [ASC | DESC], ... [WITH ROLLUP]] [HAVINGwhere_condition
] [ORDER BY {col_name
|expr
|position
} [ASC | DESC], ...] [LIMIT {[offset
,]row_count
|row_count
OFFSEToffset
}] [PROCEDUREprocedure_name
(argument_list
)] [INTO OUTFILE 'file_name
' [CHARACTER SETcharset_name
]export_options
| INTO DUMPFILE 'file_name
' | INTOvar_name
[,var_name
]] [FOR UPDATE | LOCK IN SHARE MODE]]
SQL-server
Fra Transact-SQL-referencen:
<SELECT statement> ::= [WITH <common_table_expression> [,...n]] <query_expression> [ ORDER BY { order_by_expression | column_position [ ASC | DESC ] } [ ,...n ] ] [ <FOR Clause>] [ OPTION ( <query_hint> [ ,...n ] ) ] <query_expression> ::= { <query_specification> | ( <query_expression> ) } [ { UNION [ ALL ] | EXCEPT | INTERSECT } <query_specification> | ( <query_expression> ) [...n ] ] <query_specification> ::= SELECT [ ALL | DISTINCT ] [TOP ( expression ) [PERCENT] [ WITH TIES ] ] < select_list > [ INTO new_table ] [ FROM { <table_source> } [ ,...n ] ] [ WHERE <search_condition> ] [ <GROUP BY> ] [ HAVING < search_condition > ]
PostgreSQL
Fra PostgreSQL 9.5-manualen:
[ WITH [ RECURSIVE ] with_query [, ...] ] SELECT [ ALL | DISTINCT [ ON ( expression [, ...] ) ] ] [ * | expression [ [ AS ] output_name ] [, ...] ] [ FROM from_item [, ...] ] [ WHERE condition ] [ GROUP BY grouping_element [, ...] ] [ HAVING condition [, ...] ] [ WINDOW window_name AS ( window_definition ) [, ...] ] [ { UNION | INTERSECT | EXCEPT } [ ALL | DISTINCT ] select ] [ ORDER BY expression [ ASC | DESC | USING operator ] [ NULLS { FIRST | LAST } ] [, ...] ] [ LIMIT { count | ALL } ] [ OFFSET start [ ROW | ROWS ] ] [ FETCH { FIRST | NEXT } [ count ] { ROW | ROWS } ONLY ] [ FOR { UPDATE | NO KEY UPDATE | SHARE | KEY SHARE } [ OF table_name [, ...] ] [ NOWAIT | SKIP LOCKED ] [...] ] where from_item can be one of: [ ONLY ] table_name [ * ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ] [ TABLESAMPLE sampling_method ( argument [, ...] ) [ REPEATABLE ( seed ) ] ] [ LATERAL ] ( select ) [ AS ] alias [ ( column_alias [, ...] ) ] with_query_name [ [ AS ] alias [ ( column_alias [, ...] ) ] ] [ LATERAL ] function_name ( [ argument [, ...] ] ) [ WITH ORDINALITY ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ] [ LATERAL ] function_name ( [ argument [, ...] ] ) [ AS ] alias ( column_definition [, ...] ) [ LATERAL ] function_name ( [ argument [, ...] ] ) AS ( column_definition [, ...] ) [ LATERAL ] ROWS FROM( function_name ( [ argument [, ...] ] ) [ AS ( column_definition [, ...] ) ] [, ...] ) [ WITH ORDINALITY ] [ [ AS ] alias [ ( column_alias [, ...] ) ] ] from_item [ NATURAL ] join_type from_item [ ON join_condition | USING ( join_column [, ...] ) ] and grouping_element can be one of: ( ) expression ( expression [, ...] ) ROLLUP ( { expression | ( expression [, ...] ) } [, ...] ) CUBE ( { expression | ( expression [, ...] ) } [, ...] ) GROUPING SETS ( grouping_element [, ...] ) and with_query is: with_query_name [ ( column_name [, ...] ) ] AS ( select | values | insert | update | delete ) TABLE [ ONLY ] table_name [ * ]
Oracle-database
Fra Oracle Database Online Documentation 12c Udgivelse 1 (12.1):
subquery [ for_update_clause ] ;
Her er en oversigt over mulighederne.
underforespørgsel::=
{ query_block | subquery { UNION [ALL] | INTERSECT | MINUS } subquery [ { UNION [ALL] | INTERSECT | MINUS } subquery ]... | ( subquery ) } [ order_by_clause ] [ row_limiting_clause ]
for_update_clause ::=
FOR UPDATE [ OF [ [ schema. ] { table | view } . ] column [, [ [ schema. ] { table | view } . ] column ]... ] [ { NOWAIT | WAIT integer | SKIP LOCKED } ]
Se den officielle Oracle-dokumentation for en forklaring af komponentundersætningerne.
Brug af GUI
De fleste DBMS GUI'er har en "Query Builder" eller lignende til at bygge komplekse forespørgsler. For eksempel har SQL Server Management Studio Query Designer, der leverer denne funktionalitet.