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bell@sanja.is.com.ua
2004-03-16 17:35:49 +02:00
3 changed files with 20 additions and 2 deletions

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@ -320,3 +320,9 @@ id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY <derived2> system NULL NULL NULL NULL 1
2 DERIVED t2 range PRIMARY PRIMARY 4 NULL 2 Using where; Using index
drop table t2;
CREATE TABLE `t1` ( `itemid` int(11) NOT NULL default '0', `grpid` varchar(15) NOT NULL default '', `vendor` int(11) NOT NULL default '0', `date_` date NOT NULL default '0000-00-00', `price` decimal(12,2) NOT NULL default '0.00', PRIMARY KEY (`itemid`,`grpid`,`vendor`,`date_`), KEY `itemid` (`itemid`,`vendor`), KEY `itemid_2` (`itemid`,`date_`));
insert into t1 values (128, 'rozn', 2, now(), 10),(128, 'rozn', 1, now(), 10);
SELECT MIN(price) min, MAX(price) max, AVG(price) avg FROM (SELECT SUBSTRING( MAX(concat(date_,";",price)), 12) price FROM t1 WHERE itemid=128 AND grpid='rozn' GROUP BY itemid, grpid, vendor) lastprices;
min max avg
10.00 10.00 10
DROP TABLE t1;

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@ -188,7 +188,6 @@ INSERT INTO t3 VALUES (1000,0.00),(1001,0.25),(1002,0.50),(1003,0.75),(1008,1.00
select 497, TMP.ID, NULL from (select 497 as ID, MAX(t3.DATA) as DATA from t1 join t2 on (t1.ObjectID = t2.ID) join t3 on (t1.ObjectID = t3.ID) group by t2.ParID order by DATA DESC) as TMP;
drop table t1, t2, t3;
#
# explain derived
#
@ -206,3 +205,11 @@ insert into t2 values (1,7),(2,7);
explain select a from t2 where a>1;
explain select a from (select a from t2 where a>1) tt;
drop table t2;
#
# select list counter
#
CREATE TABLE `t1` ( `itemid` int(11) NOT NULL default '0', `grpid` varchar(15) NOT NULL default '', `vendor` int(11) NOT NULL default '0', `date_` date NOT NULL default '0000-00-00', `price` decimal(12,2) NOT NULL default '0.00', PRIMARY KEY (`itemid`,`grpid`,`vendor`,`date_`), KEY `itemid` (`itemid`,`vendor`), KEY `itemid_2` (`itemid`,`date_`));
insert into t1 values (128, 'rozn', 2, now(), 10),(128, 'rozn', 1, now(), 10);
SELECT MIN(price) min, MAX(price) max, AVG(price) avg FROM (SELECT SUBSTRING( MAX(concat(date_,";",price)), 12) price FROM t1 WHERE itemid=128 AND grpid='rozn' GROUP BY itemid, grpid, vendor) lastprices;
DROP TABLE t1;