SQL Joining tables; can you repeat columns? - sql-server

Question

I'm trying to compose a view that we can use to export our inventory.
I have two tables:
Inventory, which contains the columns Description, Year, Make, Model, and Serial.
Pictures, which contains the columns DocumentBody, MimeType, Serial, and Last Modified.
I'd like to make a view that has all columns from Inventory, and also adds columns for x amount of Pictures related to Serial number.
So if there were two pictures with the same serial number, the resultant table would include these fields:
Description, Year, Make, Model, Serial, DocumentBody1, MimeType1, Last Modified1, DocumentBody2, MimeType2, Last Modified2.
For those Inventory items that only have one picture, the second picture columns would all be null.
Is this something I can even do? From what I'm reading about joins, it doesn't seem possible.

Answer 1

As others have said, you should probably evaluate whether you actually need the view you think you need. But if you really want it, you could use PIVOT in MSSQL:
WITH BaseData AS
(
SELECT Serial
,DocumentBody
,MimeType
,LastModified
,ROWNUMBER() OVER(PARTITION BY Serial ORDER BY LastModified) AS RowNum
FROM Pictures) AS t
),
DocumentPivot AS (
SELECT
Serial
,DocumentBody
,'DocumentBody' + RowNum AS ColumnName
FROM BaseData
),
MimePivot AS (
SELECT
Serial
,MimeType
,'MimeType' + RowNum AS ColumnName
FROM BaseData
),
ModifiedPivot AS (
SELECT
Serial
,LastModified
,'LastModified' + RowNum AS ColumnName
FROM BaseData
)
SELECT Description
,Year
,Make
,Model
,Inventory.Serial
,DocumentBody1
,MimeType1
,LastModified1
,DocumentBody2
,MimeType2
,LastModified2
,...
,LastModified10
FROM Inventory
LEFT OUTER JOIN (
SELECT Serial
,DocumentBody1
,DocumentBody2
,...
,DocumentBody10
FROM DocumentPivot
PIVOT (MAX(DocumentBody) FOR ColumnName IN (DocumentBody1, DocumentBody2, ..., DocumentBody10)) AS P1
) AS Documents
ON Documents.Serial=Inventory.Serial
LEFT OUTER JOIN (
SELECT Serial
,MimeType1
,MimeType2
,...
,MimeType10
FROM MimePivot
PIVOT (MAX(MimeType) FOR ColumnName IN (MimeType1, MimeType2, ..., MimeType10)) AS P2
) AS Mimes
ON Mimes.Serial=Inventory.Serial
LEFT OUTER JOIN (
SELECT Serial
,LastModified1
,LastModified2
,...
,LastModified10
FROM ModifiedPivot
PIVOT (MAX(LastModified) FOR ColumnName IN (LastModified1, LastModified2, ..., LastModified10)) AS P3
) AS Modifieds
ON Modifieds.Serial=Inventory.Serial

Answer 2

Select inventory.*, count(pictures.serial) as picture_count From inventory Left Join pictures On inventory.serial = pictures.serial Where [your where statement]
Use Left Join in case there are no pictures at all. This way you still get back a result.
Update
Actually, after reading your question again, it seems you just want to extend your search results with each additional picture in the system. That's not the best way to do this. The best you can do is just get a row returned for each pic that's in the system.
Select inventory.*, pictures.DocumentBody, pictures.MimeType, pictures.Serial, pictures.Last_Modified From inventory Left Join pictures On inventory.serial = pictures.serial Where [your where statement]
Since there is no "Group By" clause, this will give you 1 row for each picture. Then you can just loop through the results.
Also
There are ways to do this by making temp tables, looping through results within a stored procedure, creating new columns (DocumentBody1, DocumentBody2, etc) for each picture result and adding the data to the new fields, then querying the temp table. But that's a lot to go through I would think.

Answer 3

thanks for the help everyone. In the end, I ended up using PHP to accomplish this with the following code:
<?php
date_default_timezone_set('America/Edmonton');
$serverName = "database";
$connectionInfo = array( "Database"=>"CRM_MSCRM");
$conn = sqlsrv_connect( $serverName, $connectionInfo);
if( $conn === false )
{
echo "Unable to connect.\n\n";
die( print_r( sqlsrv_errors(), true));
}
else
{
echo "Connected. Selecting trucks...\n\n";
}
$tsql = "SELECT * FROM CRM_MSCRM.dbo.Trader_Export_Simple";
$stmt = sqlsrv_query( $conn, $tsql);
if( $stmt === false )
{
echo "Error executing query.\n\n";
die( print_r( sqlsrv_errors(), true));
}
$csvData = array();
while ($row = sqlsrv_fetch_array($stmt))
{
$count = 1;
$mainpicsql = "SELECT * FROM CRM_MSCRM.dbo.TruckImages WHERE Serial = '".$row[0]."' AND MainPic = 1";
$mainpicstmt = sqlsrv_query( $conn, $mainpicsql);
while ($mainpicrow = sqlsrv_fetch_array($mainpicstmt))
{
$truck = $mainpicrow[1];
$mainfilename = $truck ."-". $count . ".png";
file_put_contents($mainfilename, base64_decode($mainpicrow[0]));
$mainpicdate = $mainpicrow[3]->format("d/m/Y h:m:s");
$mainfilename = "http://images.website/images/".$mainfilename;
echo $mainpicdate."\n";
}
$picsql = "SELECT * FROM CRM_MSCRM.dbo.TruckImages WHERE Serial = '".$row[0]."' AND MainPic = 0";
$picstmt = sqlsrv_query( $conn, $picsql);
$extrapicsdate = "";
$filenames = "";
while ($picrow = sqlsrv_fetch_array($picstmt))
{
$count++;
$filename = $picrow[1] ."-". $count . ".png";
file_put_contents($filename, base64_decode($picrow[0]));
$picdate = $picrow[3]->format("d/m/Y h:m:s");
$filenames .= "http://images.website/images/".$filename.";";
$extrapicsdate .= $picdate.";";
}
$filenames = rtrim($filenames, ";");
$extrapicsdate = rtrim($extrapicsdate, ";");
echo $filenames."\n";
echo $extrapicsdate."\n";
if ($truck != "") {
$csvData[] = array($truck, $mainfilename, $mainpicdate, $filenames, $extrapicsdate);
}
if ($filenames != "")
{
$filenames = "";
}
if ($extrapicsdate != "")
{
$extrapicsdate = "";
}
echo "Next truck...\n\n";
$truck = "";
$mainfilename = "";
$mainpicdate = "";
}
$fp = fopen('file.csv', 'w');
foreach ($csvData as $fields) {
fputcsv($fp, $fields);
}
//print_r($csvData);
sqlsrv_free_stmt( $stmt);
sqlsrv_free_stmt( $picstmt);
sqlsrv_close( $conn);
?>
this gets the files out but I still have to merge the resultant CSV with the main "information" CSV.