Sql Join查询问题

Question

我的名为tutor_signup_form的mysql表看起来像这样

id    feerange    gender    name
1     20          male      alex      
2     10          female    Robin
3     15          male      Babu

现在我有一个html搜索表单，其中很少下拉所选字段，并且存在许多Chckbox字段。我想使用sql INNER JOIN从多个表中获取搜索结果。我的INNER JOIN查询看起来像这样

// search query
$query =  mysql_query("SELECT tutor_signup_form . *, tutor_signup_edu_psle . *,
tutor_signup_edu_olevel . *, tutor_signup_edu_alevel . *, tutor_signup_edu_diploma . *,
tutor_signup_edu_degree . *, tutor_signup_edu_masters . *, tutor_signup_edu_psd . *,
tutor_signup_level_primary . *, tutor_signup_level_olevel . *, tutor_signup_level_alevel . *,
tutor_signup_level_int . *, tutor_signup_level_uni . *, tutor_signup_level_music . *,
tutor_signup_level_lang . *, tutor_signup_level_com . *, tutor_signup_pre_central . *,
tutor_signup_pre_east . *, tutor_signup_pre_west . *, tutor_signup_pre_south . *,
tutor_signup_pre_north . *, tutor_signup_pre_ne . *, tutor_signup_pre_nw . *  FROM tutor_signup_form

INNER JOIN tutor_signup_edu_psle ON tutor_signup_form.tutor_id = tutor_signup_form.tutor_id     
INNER JOIN tutor_signup_edu_olevel ON tutor_signup_form.tutor_id = tutor_signup_edu_olevel.tutor_id
INNER JOIN tutor_signup_edu_alevel ON tutor_signup_form.tutor_id = tutor_signup_edu_alevel.tutor_id 
INNER JOIN tutor_signup_edu_diploma ON tutor_signup_form.tutor_id = tutor_signup_edu_diploma.tutor_id
INNER JOIN tutor_signup_edu_degree ON tutor_signup_form.tutor_id = tutor_signup_edu_degree.tutor_id
INNER JOIN tutor_signup_edu_masters ON tutor_signup_form.tutor_id = tutor_signup_edu_masters.tutor_id
INNER JOIN tutor_signup_edu_psd ON tutor_signup_form.tutor_id = tutor_signup_edu_psd.tutor_id
INNER JOIN tutor_signup_level_primary ON tutor_signup_form.tutor_id = tutor_signup_level_primary.tutor_id
INNER JOIN tutor_signup_level_olevel ON tutor_signup_form.tutor_id = tutor_signup_level_olevel.tutor_id
INNER JOIN tutor_signup_level_alevel ON tutor_signup_form.tutor_id = tutor_signup_level_alevel.tutor_id
INNER JOIN tutor_signup_level_int ON tutor_signup_form.tutor_id = tutor_signup_level_int.tutor_id
INNER JOIN tutor_signup_level_uni ON tutor_signup_form.tutor_id =  tutor_signup_level_uni.tutor_id
INNER JOIN tutor_signup_level_music ON tutor_signup_form.tutor_id = tutor_signup_level_music.tutor_id
INNER JOIN tutor_signup_level_lang ON tutor_signup_form.tutor_id = tutor_signup_level_lang.tutor_id
INNER JOIN tutor_signup_level_com ON tutor_signup_form.tutor_id =  tutor_signup_level_com.tutor_id
INNER JOIN tutor_signup_pre_central ON tutor_signup_form.tutor_id = tutor_signup_pre_central.tutor_id
INNER JOIN tutor_signup_pre_east ON tutor_signup_form.tutor_id = tutor_signup_pre_east.tutor_id
INNER JOIN tutor_signup_pre_west ON tutor_signup_form.tutor_id = tutor_signup_pre_west.tutor_id
INNER JOIN tutor_signup_pre_south ON tutor_signup_form.tutor_id = tutor_signup_pre_south.tutor_id
INNER JOIN tutor_signup_pre_north ON tutor_signup_form.tutor_id =  tutor_signup_pre_north.tutor_id
INNER JOIN tutor_signup_pre_ne ON tutor_signup_form.tutor_id = tutor_signup_pre_ne.tutor_id
INNER JOIN tutor_signup_pre_nw ON tutor_signup_form.tutor_id = tutor_signup_pre_nw.tutor_id 

WHERE tutor_signup_form.feerange <= '$budget'");  

例如，我选择了预算字段= 20.因此，我的查询应该只是来自tutor_signup_form的产品3结果，但它会产生24个结果。我不明白它为什么会产生24个结果。你能解决它吗？

更新：

Answer 1

正如Deadman所说，笛卡儿......

您的第一个内部联接是表名的复制/粘贴

INNER JOIN tutor_signup_edu_psle 
   ON tutor_signup_form.tutor_id = tutor_signup_form.tutor_id     

应该是

INNER JOIN tutor_signup_edu_psle 
   ON tutor_signup_form.tutor_id = tutor_signup_edu_psle.tutor_id     

我没有读过去，但是会在平均时间

此外，您拥有所有联接作为INNER JOIN。如果有人在其中一个表（例如音乐）中没有记录，但是在计算机中进行辅导，并且有人搜索计算机，则不会返回这些记录。我建议所有人都改为LEFT JOIN，所以如果记录存在于辅导子级别，那么你很好，不会失去它。

Answer 2

如果我做得对，你需要检查你的where子句。我认为参与加入的表的笛卡尔积。 笛卡尔积结果集的大小是第一个表中的行数乘以第二个表中的行数