摘要:
SQL server如何查看视图的字段信息 查询语句 SELECT object_name( id ) AS 表名 , c.name AS 字段名 , t.name 数据类型 , c.prec AS 长度 FROM syscolumns c INNER JOIN systypes t ON c.xu 阅读全文
摘要:
JDK1.8中,对HashMap的hash算法和寻址算法有何优化? HashMap源码 1. hash(Object key)算法 Computes key.hashCode() and spreads (XORs) higher bits of hash to lower. Because the 阅读全文
摘要:
The SELECT would examine more than MAX_JOIN_SIZE rows; check your WHERE and use SET SQL_BIG_SELECTS=1 or SET MAX_JOIN_SIZE=# if the SELECT is okay 背景 阅读全文