1.这里先准备数据库:在数据库中建立一个News数据表,字段为id,title,content2.建立用于插入news的存储过程:NewsInsert和NewsUpdate,代码如下: ),@content text AS Insert Into News (title,content) Values (@title,'') ) SELECT @ptrval = TEXTPTR(content) FROM News WHERE id = @@identity writeTEXT News .co
根据字段名和对应的值查询. (正确代码):目前发现,需要"分组,排序"等才能解决,如"order by","group by"等. SQL代码: ALTER PROCEDURE USP_QueryT_AddressBookByField ), --字段名. ) --字段对应的值. AS SET NOCOUNT ON declare @query nvarchar(max) set @query = 'select [FId] as [编号],[F
问题:有一张表hy_test,查找其字段name中包含ufo的记录数,下面哪种方案最快? A.select count(*) from hy_test where name like '%ufo%' B.select count(*) from hy_test where instr(name,'ufo')> 0 C.with temp as (select rowid from hy_test t where t.name like '%ufo%') select count(*) from
select count(1) from pd_xxx_origin_xxx_data where create_time like '2019-02-23%' and source='20036' SELECT sum(case when create_time like '2019-02-23%' then 1 else 0 end) as inst_count, sum(case when active_time like '2019-02-23%' then 1 else 0 en
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
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
一.查询SQL Server中所有的表 SQL语句:SELECT * FROM sys.tables name列表示所有的表名. 二.查询SQL Server中所有的列 SQL语句:SELECT * FROM sys.columns name列表示所有的字段名称. 两张表根据object_id进行关联. 语法: select * from sys.tables t inner join sys.columns c on t.object_id=c.object and c.name='要查询的字
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
sql查询某字段的相同值: SELECT * FROM table WHERE col in (SELECT col FROM table GROUP BY col HAVING COUNT (col) >1); 顺带说一下where和having: select * from tablewhere ···(只能对分组前的属性进行筛选)group by ···(按某个字段分组)having ···(只能对分组后的每个组的整体属性进行筛选,用聚合函数体现)--不使用group by就默认表的整