sql: 表结构查询

1 --SQL SERVER 2005 生成代码需要知道的SQL语句
2 use LibrarySystem
3 --查询当前数据库所有表和其的主键字段，字段类型，长度，是否为空值
4 SELECT d.name as ‘TableName‘,a.name as ‘FieldName‘,b.name as ‘TypeName‘,a.length as ‘Length‘,a.isnullable as ‘IS_NULL‘ FROM  syscolumns  a,  systypes b,sysobjects d ,INFORMATION_SCHEMA.KEY_COLUMN_USAGE c WHERE  a.xtype=b.xusertype  and  a.id=d.id  and  d.xtype=‘U‘ and c.TABLE_NAME   = d.name and c.COLUMN_NAME=a.name
5 --获取BookKindList表结构里面的字段名， 类型，长度
6 SELECT c.name   as   FieldName,t.name   as   FieldType,   c.length   as   FieldLength   FROM   SYSCOLUMNS   c   inner   join     systypes   t   on   c.xusertype=t.xusertype   WHERE   c.ID   =   OBJECT_ID(‘BookKindList‘)
7 --

 1 #数据库MySQL 6.7
 2 use sakila;
 3 #查询表名
 4 show tables;
 5 #
 6 SELECT TABLE_NAME,TABLE_ROWS FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_SCHEMA=‘sakila‘;
 7 
 8 select column_name from information_schema.columns where table_schema=‘sakila‘ and table_name=‘actor‘;
 9 #表结构 字段名， 类型，长度
10 select * from information_schema.columns where table_schema=‘sakila‘ and table_name=‘actor‘;