SQL 实战学习及优化

1. mysql 从集合列中，拎出所要查询的字段

SELECT CURDATE(), REPLACE(parent_ids,',','|') as 'replaceDisplay', FIND_IN_SET('3', REPLACE(parent_ids,'|',',')) FROM sys_menu WHERE FIND_IN_SET(3, REPLACE(parent_ids,'|',','))  

2. mysql 分析及解释

EXPLAIN SELECT CURDATE(), REPLACE(parent_ids,',','|') as 'replaceDisplay', FIND_IN_SET('3', REPLACE(parent_ids,'|',',')) FROM sys_menu WHERE FIND_IN_SET(3, REPLACE(parent_ids,'|',','))   ORDER BY RAND();SELECT CURDATE(), REPLACE(parent_ids,',','|') as 'replaceDisplay', FIND_IN_SET('3', REPLACE(parent_ids,'|',',')) FROM sys_menu WHERE FIND_IN_SET(3, REPLACE(parent_ids,'|',','))   ORDER BY RAND() procedure analyse();

3. mysql 引擎

show ENGINES;

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