数据库or、in、<>、>=、<=、butween区别
操作前先关闭数据库缓存
#创建测试的test表
DROP TABLE IF EXISTS test; CREATE TABLE test( `id` INT(10) NOT NULL, `name` VARCHAR(20) DEFAULT '' NOT NULL, `status` TINYINT(1) DEFAULT 1 NOT NULL, PRIMARY KEY( ID ) )ENGINE=INNODB DEFAULT CHARSET utf8;
插入数据
create procedure a() BEGIN DECLARE i INT DEFAULT 0; SET autocommit = 0; WHILE i<10000000 DO INSERT INTO test ( `id`,`name`,`status` ) VALUES( i, CONCAT( 'abcd', i ),i%3 ); SET i = i+1; IF i%2000 = 0 THEN // 每满2000行执行一次 COMMIT; END IF; END WHILE; END; call a();
耗时: 0.042s
先测试带主键模式下查询主键执行时间
读取10条数据 # in SELECT * FROM test WHERE id IN (1,2,3,4,5,6,7,8,9,10); 用时:0.001 # or SELECT * FROM test WHERE id =1 OR id=2 OR id=3 OR id=4 OR id=5 OR id=6 OR id=7 OR id=8 OR id=9 OR id=10; 用时:0.001 # between SELECT * FROM test WHERE id between 1 and 10; 用时:0.001 # <> SELECT * FROM test WHERE id>=1 and id<=10; 用时:0.001 # <= SELECT * FROM test WHERE id <= 10; 用时:0.001
读取1000条数据 # in SELECT * FROM test WHERE id IN (1,2,3,...1000); 用时:0.003 # or SELECT * FROM test WHERE id =1 OR id=2 OR id=3 OR... id=1000; 用时:0.019 # between SELECT * FROM test WHERE id between 1 and 100; 用时:0.002 # <> SELECT * FROM test WHERE id>=1 and id<=1000; 用时:0.002 # <= SELECT * FROM test WHERE id <= 1000; 用时:0.002
读取10000条数据 # in SELECT * FROM test WHERE id IN (1,2,3,...10000);
用时:0.027
# or
SELECT * FROM test WHERE id =1 OR id=2 OR id=3 OR... id=10000;
执行用时:4.834 # between SELECT * FROM test WHERE id between 1 and 10000; 用时:0.008 # <> SELECT * FROM test WHERE id>=1 and id<=10000; 用时:0.008 # <= SELECT * FROM test WHERE id <= 10000; 用时:0.008
读取50000条数据(sql语句太长,10万数据 in和or会崩溃) # in SELECT * FROM test WHERE id IN (1,2,3,...50000); 用时:5.193s # or SELECT * FROM test WHERE id =1 OR id=2 OR id=3 OR... id=50000; 用时:(sql语句太长,电脑崩溃) # between SELECT * FROM test WHERE id between 1 and 50000; 用时:0.035s # <> SELECT * FROM test WHERE id>=1 and id<=50000; 用时:0.032s # <= SELECT * FROM test WHERE id <= 50000; 用时:0.031s
在主键id上 in的效率要高于or;其它几个比较符相近。
测试非主键 status
读取10000000条数据(一千万条数据) # in SELECT * FROM test WHERE status IN (0,1); 用时:6.736s # or SELECT * FROM test WHERE status =0 OR status=1; 用时:6.655s # between SELECT * FROM test WHERE status between 0 and 1; 用时:6.476s # <> SELECT * FROM test WHERE status>=0 and status<=1; 用时:6.680s # <= SELECT * FROM test WHERE status <= 1; 用时:6.440s
# <>
SELECT * FROM test WHERE status <> 2;
用时:6.263s
当id的主键索引去除后
读取10000000条数据(一千万条数据) # in SELECT * FROM test WHERE status IN (0,1); 用时:7.888s # or SELECT * FROM test WHERE status =0 OR status=1; 用时:7.770s # between SELECT * FROM test WHERE status between 0 and 1; 用时:7.989s # <= => SELECT * FROM test WHERE status>=0 and status<=1; 用时:7.835s # <= SELECT * FROM test WHERE status <= 1; 用时:7.476s # <> SELECT * FROM test WHERE status <> 2; 用时:8.346s
非主键字段有无主键索引差距不是很大。
强制走主键索引
select * from test force index(PRIMARY) where status in (0,1);
用时:10.930