Powerbuilder中直接使用SQL语句报错

1. time应能够不能加[]
2. lesson =:'' 应该去掉冒号：
3. v_count是数字，不能应该是 V_count =0

SELECT COUNT(1)
INTO :V_count
FROM db_schedule
where classroom =:ls_classroom and time =:ls_time and ( lesson ='' or lesson is null );

if V_count =0 then
messagebox('警告','教室已用!')
end if

PB里面如果需要直接对数据库查询的话应先预定义SQL连接，指定你要对哪个数据库连接 ，例如定义连接为SQL1
则你的语句应为

SELECT COUNT(1)
INTO :V_count
FROM db_schedule
where classroom =: ls_classroom and [time] =: ls_time and ( lesson ='' or lesson is null ) using sql1;

if V_count ='0' then
messagebox('警告','教室已用!')
end if

SELECT COUNT(1)
INTO :V_count
FROM db_schedule
where classroom =:ls_classroom and [time] =:ls_time and ( lesson ='' or lesson is null );

if V_count =0 then
messagebox('警告','教室已用!')
end if

这样写应该就可以