sql.Format("select tb_student_information.student_number, \
tb_student_information.student_name,tb_student_information.student_class, \
tb_student_answered.question_number,tb_student_answered.question_cishu, \
tb_student_answered.times, tb_student_answered.submit_time,\
tb_student_answered.score from tb_student_information, \
tb_student_answered where tb_student_information.student_number=\
tb_student_answered.student_number and tb_student_answered.score!=\'%s\' \
and tb_student_information.student_class=\'%s\' \
and tb_student_answered.question_cishu=\'%s\'", "0", class_name, times);
//执行sql语句
pRecordset->Open((_variant_t)sql,
pConnection.GetInterfacePtr(),
adOpenDynamic,
adLockOptimistic,
adCmdText);
tb_student_information.student_name,tb_student_information.student_class, \
tb_student_answered.question_number,tb_student_answered.question_cishu, \
tb_student_answered.times, tb_student_answered.submit_time,\
tb_student_answered.score from tb_student_information, \
tb_student_answered where tb_student_information.student_number=\
tb_student_answered.student_number and tb_student_answered.score!=\'%s\' \
and tb_student_information.student_class=\'%s\' \
and tb_student_answered.question_cishu=\'%s\'", "0", class_name, times);
//执行sql语句
pRecordset->Open((_variant_t)sql,
pConnection.GetInterfacePtr(),
adOpenDynamic,
adLockOptimistic,
adCmdText);
sql.Format("select ta.student_number,"+ //c#里面字符串拼接用 + 号
ta.student_name,ta.student_class,"+
tb.question_number,tb.question_cishu,"+
tb.times,d.submit_time,"+
tb.score
from tb_student_information ta,"+ //当表名过长时,最好个表取个别名
tb_student_answered tb
where ta.student_number=tb.student_number"+
and tb.score not like \'%s\'"+ //oracle里面模式匹配使用like而不用!=号
and ta.student_class not like \'%s\'"+
and tb.question_cishu like \'%s\'", "0", class_name, times);
--字符串拼接,要注意双引号和转移字符的使用
sql.Format("select ta.student_number,"+ //c#里面字符串拼接用 + 号
"ta.student_name,ta.student_class,"+
"tb.question_number,tb.question_cishu,"+
"tb.times,d.submit_time,"+
"tb.score
"from tb_student_information ta,"+ //当表名过长时,最好个表取个别名
"tb_student_answered tb
"where ta.student_number=tb.student_number"+
"and tb.score not like \'%s\'"+ //oracle里面模式匹配使用like而不用!=号
"and ta.student_class not like \'%s\'"+
"and tb.question_cishu like \'%s\'", "0", class_name, times);