七牛云如何做网站缓存,网站怎么弄实名制认证,国外做连接器平台网站,广州seo推广培训二、通过修改系统表(pg_attribute)达到字段重新排序的目的有关系统表的概述及用途可以查看官网#xff1a;http://www.pgsqldb.org/pgsqldoc-cvs/catalogs.html
表名字表用途pg_class表#xff0c;索引#xff0c;序列#xff0c;视图#xff08;”关系”#xff09;pg_…二、通过修改系统表(pg_attribute)达到字段重新排序的目的有关系统表的概述及用途可以查看官网http://www.pgsqldb.org/pgsqldoc-cvs/catalogs.html
表名字表用途pg_class表索引序列视图”关系”pg_attribute表的列”属性””字段”
①通过pg_class查找[表,索引,视图等的名字][表在磁盘上的文件的名字] SELECT relname, relfilenode FROM pg_class WHERE relname’order_change_table’; 查询结果为order_change_table | 12666②通过pg_attribute查找[此列/字段所属的表][字段名字][字段数目] SELECT attrelid, attname, attnum FROM pg_attribute WHERE attrelid12666; 查询结果为12666 | id | 1 12666 | name | 2 12666 | password | 3 12666 | new_field | 4③更新pg_attribute的[attnum]字段(将要移动的字段先更新成数据库里面没有的值再按顺序更新)。 UPDATE pg_attribute SET attnum7 WHERE attname’new_field’ AND attrelid12666; UPDATE pg_attribute SET attnum6 WHERE attname’name’ AND attrelid12666; UPDATE pg_attribute SET attnum5 WHERE attname’password’ AND attrelid12666; UPDATE pg_attribute SET attnum2 WHERE attname’new_field’ AND attrelid12666; UPDATE pg_attribute SET attnum3 WHERE attname’name’ AND attrelid12666; UPDATE pg_attribute SET attnum4 WHERE attname’password’ AND attrelid12666;④再检索表字段就已经改好顺序了。(缺点一旦改错表就崩溃事先一定要备份好。优点直达根处) SELECT * FROM order_change_table;
