前置语句
查询指定库中的所以表和所有字段:
SELECT a.TABLE_NAME '表名', ORDINAL_POSITION '顺序', COLUMN_NAME '字段', DATA_TYPE '类型', CHARACTER_OCTET_LENGTH '字节长', IF(COLUMN_KEY = 'PRI', "√", "")'主键', IF( EXTRA = 'auto_increment', "√", "" )'自增长', IF(IS_NULLABLE = 'YES', "√", "")'空', CHARACTER_SET_NAME '编码', COLUMN_DEFAULT '默认值', COLUMN_COMMENT '说明' FROM information_schema. COLUMNS a join information_schema.TABLES b on a.TABLE_NAME=b.TABLE_NAME WHERE b.Table_SCHEMA='database_name'