[jeeplus] 使用笔记 (gridSelect、datetimepicker etc.)

java.sql.SQLException: Connection is read-only. Queries leading to data modification are not allowed

解决方法：事务配置在 service 层，但是你的 service 层的方法是 query 开头的，service 调用的 query 方法根本就没有事务。你的配置文件下面是不是还有关于 query*的配置成了 read-only？修改你 service 方法的开头变成不是 read-only 的那种配置，如 clear 开头。（在 query 方法名(read_only)里面执行了 update 操作，所以就报错了。）

    //删除转化出现异常时已经插入的数据记录
    @Transactional(readOnly = false)
    public void deleteERecord(LevelForMajors levelForMajors){
        mapper.deleteERecord(levelForMajors);
    }

根据某列中的值是否包含某个字符串筛选记录：

UPDATE m_levelformajor 
SET type = (
	CASE
		WHEN 1 < LENGTH(number) AND  LENGTH(number) < 3 THEN "22"
		WHEN 3 < LENGTH(number) AND  LENGTH(number) < 5 THEN "23"
		WHEN 6 <= LENGTH(number) THEN "24"
		WHEN number IS NULL THEN "21"
	ELSE
		"1"
	END
)
WHERE find_in_set('19db900b7129468385d96f96cd6c672a', parent_ids);

--设置本科专业记录的 type
UPDATE m_levelformajor 
SET type = (
	CASE
		WHEN 1 < LENGTH(number) AND  LENGTH(number) < 3 THEN "12"
		WHEN 3 < LENGTH(number) AND  LENGTH(number) < 5 THEN "13"
		WHEN 6 <= LENGTH(number) THEN "14"
		WHEN number IS NULL THEN "11"
	ELSE
		"1"
	END
)
WHERE find_in_set('e131fdeaf3f041b086bec4e68dd096c7', parent_ids);``` 

SSM 中 MyBatis 的某个 xxxMapper.xml 中，是否可以这样写？

            <if test="planMajorName != null and  planMajorName != '' and r1 = '0'">
                AND a.planmajorname = #{planMajorName}
            </if>
            <if test="planMajorName != null and  planMajorName != '' and (r1 = null or r1 = '')">
                AND a.planmajorname LIKE
                <if test="dbName == 'oracle'">'%'||#{planMajorName}||'%'</if>
                <if test="dbName == 'mssql'">'%'+#{planMajorName}+'%'</if>
                <if test="dbName == 'mysql'">concat('%',#{planMajorName},'%')</if>
            </if>