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[英]INSERT INTO … VALUES … SELECT. How to make nested statement with INSERT?
[英]How to my stored procedure make it fast and beautiful…( select . select. select.. )
我是初級Ruby-mysql程序員,我想知道如何快速完成(存儲過程)查詢結果。
這是我的存儲過程,我正在使用SQL_CACHE ..但我不確定..緩存使我的過程快速..:(
DROP PROCEDURE IF EXISTS GET_AV //
CREATE PROCEDURE GET_AV()
BEGIN
DECLARE OVERALL FLOAT ;
DECLARE MALE FLOAT ;
DECLARE FEMALE FLOAT ;
DECLARE UNDER25 FLOAT ;
DECLARE ABOVE25 FLOAT ;
DECLARE UNDER25MALE FLOAT ;
DECLARE UNDER25FEMALE FLOAT ;
DECLARE ABOVE25MALE FLOAT ;
DECLARE ABOVE25FEMALE FLOAT ;
DECLARE CNT FLOAT;
#AVERAGE OVERALL
select SQL_CACHE avg(r.frq) as AVG_OVERALL INTO OVERALL from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id;
#AVERAGE MALE
select SQL_CACHE avg(r.frq) as AVG_MALE INTO MALE from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id WHERE GENDER = 1;
#AVERAGE FEMALE
select SQL_CACHE avg(r.frq) as AVG_FEMALE INTO FEMALE from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id WHERE GENDER = 2;
#AVERAGE UNDER25
select SQL_CACHE avg(r.frq) as AVG_UNDER_25 INTO UNDER25 from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id where AGE <= 25;
#AVERAGE ABOVE25
select avg(r.frq) as AVG_ABOVE_25 INTO ABOVE25 from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id where AGE >= 25;
#AVERAGE UNDER 25 & MALE
select SQL_CACHE avg(r.frq) as AVG_UNDER_25_MALE INTO UNDER25MALE from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id WHERE AGE <= 25 AND GENDER = 1;
#AVERAGE UNDER 25 & FEMALE
select SQL_CACHE avg(r.frq) as AVG_UNDER_25_FEMALE INTO UNDER25FEMALE from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id WHERE AGE <= 25 AND GENDER = 2;
#AVERAGE ABOVE25 & MALE
select SQL_CACHE avg(r.frq) as AVG_ABOVE_25_MALE INTO ABOVE25MALE from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id where AGE >=25 AND GENDER = 1;
#AVERAGE ABOVE25 & FEMALE
select SQL_CACHE avg(r.frq) as AVG_ABOVE_25_FEMALE INTO ABOVE25FEMALE from tbl_survey as s inner join tbl_respondent as r on s.s_id = r.s_id WHERE AGE >= 25 AND GENDER = 2;
SELECT OVERALL,MALE,FEMALE,UNDER25 ,ABOVE25 , UNDER25MALE,UNDER25FEMALE ,
ABOVE25MALE ,ABOVE25FEMALE;
END //
幸運的是它現在並不太慢..但是我想知道如何使它越來越快和漂亮的代碼方式:(
BEGIN
SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED; // These line helps to avoid locking table
<Your select Query>
SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;
END
// As you are using same table number of times in the stored procedure
// You can create temp table for that. This will avoid scan whole table from db.
CREATE TEMPORARY TABLE IF NOT EXISTS tmptbl_survey ENGINE=MEMORY AS SELECT
* FROM tbl_survey
// Use temp table in the query
//Then drop temp table
DROP TABLE tmptbl_survey
祝你好運
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