8
: SQL. .
: SQL- , SQL, .
SELECT
SELECT :
, ();
WHERE- HAVING- ( , " ");
CREAT VIEW, DECLARE CURSOR INSERT;
(INTO-). :
(*) "" - , .. " , ";
([]) , , , (.. );
({}) , , , , .. , , SQL;
(...) , ;
(|) . ASC|DESC , ASC DESC; , , (, [ASC]|DESC , ASC); (;) SQL;
(,) ;
() SQL;
SQL ( ) , ;
, , , (_);
, ,... ( ) _, _,..., ;
, _, ; ( ) () _ (). SELECT () : [UNION [ALL] ]... [ORDER BY {[.] | __SELECT} [[ASC] | DESC] [,{[.] | __SELECT} [[ASC] | DESC]]...;
|
|
|
(UNION) (ORDER BY) , "". - ASC (ASCending) DESC (DESCending), ASC.
( )
SELECT () ( ) ()
FROM () ,
WHERE ()
GROUP BY ( ) , , SELECT SQL- SUM (), COUNT (), MIN ( ), MAX ( ) AVG ( )
HAVING () ,
SELECT [[ALL] | DISTINCT]{ * | _SELECT [,_SELECT]...} FROM {_ | } [] [,{_ | } []]... [WHERE ] [GROUP BY [HAVING ]];
_SELECT - : [.]* | | SQL_ | _
: [.] | () | |
({[ [+] | - ] { | _} [ + | - | * | ** ]}...)
SQL_ : {SUM|AVG|MIN|MAX|COUNT} ([[ALL]|DISTINCT][.]) {SUM|AVG|MIN|MAX|COUNT} ([ALL] ) COUNT(*)
WHERE : WHERE [NOT] WHERE_ [[AND|OR][NOT] WHERE_]...
WHERE_ : { = | <> | < | <= | > | >= } { | () } _1 [NOT] BETWEEN _2 AND _3 [NOT] IN { ( [,]...) | () } IS [NOT] NULL [.] [NOT] LIKE '_' [ESCAPE ''] EXISTS ()
(= | <> | < | <= | > | >=) WHERE BETWEEN (), LIKE ( ), IN (), IS NULL ( ) EXISTS (), NOT (). , :
AND - AND ;
OR - OR ;
AND NOT - ;
OR NOT - ,
AND OR ( AND OR). WHERE , .
|
|
|
- , , . , , , ASCII. , , , .
, GROUP BY
GROUP BY [.] [,[.]]... [HAVING ]
GROUP BY , , GROUP BY. , SELECT, (, ..).
HAVING ( WHERE)
HAVING [NOT] HAVING_ [[AND|OR][NOT] HAVING_]...
, :
{ = | <> | < | <= | > | >= } { | ()
| SQL_ }
{_1 | SQL__1} [NOT] BETWEEN
{_2 | SQL__2} AND {_3 | SQL__3}
{ | SQL_} [NOT] IN { ( [,]...)
| () }
{ | SQL_} IS [NOT] NULL
[.] [NOT] LIKE '_' [ESCAPE '']
EXISTS ()
