mysql text字段判断是否为空 mysql text字段为空select * from `tableName` where `textField` is null or `textField` = ''; mysql text字段不为空select * from `tableName` where `textField` is not null AND `textField` != '';
mybatis判断集合为空或者元素个数为零: <if test="mlhs != null and mlhs.size() != 0"> and t.mlh_name not in <foreach collection="mlhs" item="item1" open="(" close=")" index="i" separator=",">
/****** Object: StoredProcedure [dbo].[GetCommonGroupByRegion] Script Date: 03/23/2017 17:31:18 ******/ SET ANSI_NULLS ON GO SET QUOTED_IDENTIFIER ON GO ALTER proc [dbo].[GetCommonGroupByRegion] )=null,---车型 @CreateTimeStart datetime=null, --入会开始时间 @
package com.lanxi.demo2; import java.util.HashSet; import java.util.Iterator; import java.util.Set; public class Test { public static void main(String[] args) { //引用一个Set集合实现类 Set set=new HashSet(); //添加单个元素 set.add("哈"); set.add("士");