Question

我有4张桌子

Tbl_Items: 
   Asset Id, 
   Asset_name, 
   Workshop,
   PAT_PASS

（研讨会和PAT_PASS是YES或NO.Workshop = YES和PAT_PASS = NO表示此项目不可用于租用..）

Tbl_Project_details:
   Project_id, 
   Project_start_date, 
   project_end_date

TBL_Project_items:
   Project_id, 
   Asset_id,
   Start_date,
   End_date

我需要做一个select语句，允许我显示tbl_Items中的所有项目除外：

1) Those that are already in use on another project on the dates that I need them.
2) Are in the workshop. (Workshop = YES)
3) Are not PAT Tested (PAT_PASS = NO)

到目前为止，我已经开始使用这样一个简单的声明：

$post_project_id = "13-1309.01";  //this is just an example number..

$sql = 
"SELECT * FROM Project_details 
Where Project_id = '$post_project_id' ";  
$result = mysql_query($sql);

while ($row = mysql_fetch_array($result)) 
{
$hire_start_date = $row['Start_date']; // we find out our projects start date
$hire_end_date = $row['End_date'];     // we find out our projects end date
}  

$result=mysql_query("SELECT Items.Asset_id, Items.Name  
FROM 
Items,Project_items 
WHERE
Project_details.Start_date < '$hire_start_date' 
AND 
Project_details.End_date > '$hire_end_date'") 
or die(mysql_error());

while($row = mysql_fetch_array($result))
{
// fill up an option box with the results
}

即使这个基本脚本似乎也不起作用！这是我第一次尝试从多个表中进行选择，所以这是一个陡峭的学习曲线！

谢谢！

Answer 1

$StartDate和$EndDate是您的约会日期：

 SELECT ITEM.asset_id,
        ITEM.asset_name,
        ITEM.workshop,
        ITEM.pat_pass
   FROM Tbl_Items ITEM
        LEFT JOIN Tbl_Project_Items PJITEM
           ON PJITEM.asset_id = ITEM.asset_id
           AND PJITEM.start_date BETWEEN $StartDate AND $EndDate
           OR PJITEM.end_date BETWEEN $StartDate AND $EndDate
   WHERE ITEM.workshop = 'no'
     AND ITEM.pat_pass = 'yes' 
     AND PJITEM.asset_id IS NULL

谁是帕特？

Answer 2

我会选择子查询：

SELECT * FROM Tbl_Items AS i WHERE

这应符合您的（1.）条件：“只接受那些选择没有任何出现的记录”：

0 = (
SELECT COUNT(1) FROM TBL_Project_items AS pi
WHERE i.Asset_Id = pi.Asset_Id
AND Start_date < $hire_start_date
AND End_date > $hire_end_date
)

研讨会条件（2.）：

AND WORKSHOP != "YES"

拍摄测试条件（3）：

AND PAT_PASS != "NO"

Answer 3

一个问题：

WHERE
Project_details.Start_date < '$hire_start_date' 
AND 
Project_details.End_date > '$hire_end_date'")

“Start_date”和“End_date”列不在“Project_details”表中。在该表中，这些列似乎被命名为“Project_start_date”和“Project_end_date”。

复杂的选择语句

3 个答案: