mysql 慢查询的分析方法20
mysql开启查看慢查询日志1配置开启在mysql配置文件中增加 log-slow-queries= (指定日志文件存放位置可以为空系统会给一个缺省的文件host_)long_query_time=2 (记录超过的时间默认为10s)log-queries-not-using-indexes (log下来没有使用索引的query可以根据情况决定是否开启)log-long-format (如
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mysql多表查询(2009-05-03 19:26:53) javascript: 标签: =blogk=mysqlts=bpoststype=tag t _blank mysql =blogk=namets=bpoststype=tag t _blank name =blogk=fromts=bpoststype=tag t _blank from =blo
group by和having子句:查询各个供应商供应商品的数量:select vend_idcount(prod_id) from products group by vend_idhaving子句是对分组后的结果进行筛选:查询各个供应商供应商品的数量大于3种的供应商:select vend_idcount(prod_id) from products group by vend_id havi
一查询数值型数据:?SELECT FROM tb_name WHERE sum > 100?查询谓词:>=<<>=><>=<=?二查询字符串?SELECT FROM tb_stu ?WHERE sname ?= ?小刘?SELECT FROM tb_stu ?WHERE sname like 刘?SELECT FROM tb_stu ?WHERE sname like 程序员?SELECT
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变量查询a=hahaha(:all:conditions=>[title like {a}])(:all:conditions=>[title like :title:title=>{a}])(:all:conditions=>[title like :title and price>:price:title=>{a}:prcie=>3])相当SELECT FROM products WHERE
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