func_default.result
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:1k
源码类别:
MySQL数据库
开发平台:
Visual C++
- drop table if exists t1,t2;
- create table t1(str varchar(10) default 'def',strnull varchar(10),intg int default '10',rel double default '3.14');
- insert into t1 values ('','',0,0.0);
- select default(str), default(strnull), default(intg), default(rel) from t1;
- default(str) default(strnull) default(intg) default(rel)
- def NULL 10 3.14
- explain extended select default(str), default(strnull), default(intg), default(rel) from t1;
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 system NULL NULL NULL NULL 1
- Warnings:
- Note 1003 select default(test.t1.str) AS `default(str)`,default(test.t1.strnull) AS `default(strnull)`,default(test.t1.intg) AS `default(intg)`,default(test.t1.rel) AS `default(rel)` from test.t1
- select * from t1 where str <> default(str);
- str strnull intg rel
- 0 0
- explain select * from t1 where str <> default(str);
- id select_type table type possible_keys key key_len ref rows Extra
- 1 SIMPLE t1 system NULL NULL NULL NULL 1
- drop table t1;