1 sql 查询某字段id为空 select * from 表名 where id is null ; 2 sql 查询某字段id不为空 select * from 表名 where id is not null; 或 select * from 表名 where id <> null; // select * from 表名 where len(id) >1; // (最后两个PL/SQL下验证不正确!) 由于null 为一种状
比如 insert into table a (a1,b1)values("a1",''); 对于这种情况,因为表里存的是'',其实是没有内容的,要查询这个字段,不能直接使用 select * from a where b1=''; sql中判断非空不能用等号,因为null在sql中被看作特殊符号,必须使用关键字 is和not应该如此使用: select * from A where b1 is null 或者: select * from A where b1 is not null
from django.test import TestCase # Create your tests here. import os import sys if __name__ == "__main__": os.environ.setdefault("DJANGO_SETTINGS_MODULE", "day53.settings") import django django.setup() from app01 import model
public List<Location> getLocationList(int companyid, string searchValue, string searchField){... var dbLocList = from x in _dbLocList where x.company_id == companyid and x的searchField==searc