Apache log4j的官方介绍是“log4j is a reliable, fast and flexible logging framework (APIs) written in Java, which is distributed under the Apache Software License. log4j is highly configurable through external configuration files at runtime. It views the log…
(2.10)Mysql之SQL基础——约束及主键重复处理 关键词:mysql约束,批量插入数据主键冲突 [1]查看索引: show index from table_name; [2]查看有约束的列:select * from information_schema.key_column_usage where table_schema= 'db_name' and table_name = 'table_name'; [3]查看有约束的表及表约束类型:select * from informat…
