idea的rename注意事项
对queryPageList进行重命名
![](https://img.haomeiwen.com/i5359801/c321e4d21fb4f557.png)
第一项:方法名的修改和第二项:方法引用的修改:简单看一下就可以了。
第三项:重点看一下,若没有则排除
循环依赖的解决办法
错误信息:This is often the result of over-eager type matching - consider using 'getBeanNamesOfType' with the 'allowEagerInit' flag turned off
解决办法:在bean增加 @Lazy(value = true),利用懒加载来解决循环依赖来代替修改代码。
UNION ALL+条件与每个+条件+UNION效率相差不大
原因:sql会自己优化
执行结果:
SELECT contact_company_id
FROM base_material
WHERE contact_company_id = 1
UNION ALL
SELECT contact_company_id
FROM base_material_supplier
WHERE contact_company_id = 1;
![](https://img.haomeiwen.com/i5359801/5681dd2059f0dcb3.png)
SELECT *
FROM (
SELECT contact_company_id
FROM base_material
UNION ALL
SELECT contact_company_id
FROM base_material_supplier
) a
WHERE contact_company_id = 1;
![](https://img.haomeiwen.com/i5359801/ae0a08044944df87.png)
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