I have been searching online and even amongst Stackoverflow questions about this issue but couldnt receive any related response. The SQL query that I have shown below,
SELECT Scania.GensetType
, Scania.EngineType
, Scania.Engine60Hz
, Scania.Alternator
, Scania.PriceEur
FROM Scania
LEFT JOIN NordhavnGenset
ON Scania.GensetType=NordhavnGenset.Alternator
WHERE (NordhavnGenset.MaxKva='46')
and (Generator.Alternator='ECP34-1LN/4')
and (insulation.Insulation='F (90ºC/45ºC)')
and (Klasse.Klasse='KRS\r')
and (airinletfilter.AirInletFilter='No')
and (Ip.IP='IP23');
Always returns the error message below, and I have checked several times that this column exists in the table!
#1054 - Unknown column 'Generator.Alternator' in 'where clause'
However if I execute the query by stopping at the first Where clause, then the results are displayed,
SELECT Scania.GensetType
, Scania.EngineType
, Scania.Engine60Hz
, Scania.Alternator
, Scania.PriceEur
FROM Scania
LEFT JOIN NordhavnGenset
ON Scania.GensetType=NordhavnGenset.Alternator
WHERE (NordhavnGenset.MaxKva='46');
The new query
SELECT Scania.GensetType, Scania.EngineType, Scania.Engine60Hz, Scania.Alternator, Scania.PriceEur
FROM Scania
LEFT JOIN NordhavnGenset
ON Scania.GensetType=NordhavnGenset.Alternator
LEFT JOIN Generator
ON Scania.Alternator=Generator.Alternator
LEFT JOIN Insulation
ON NordhavnGenset.Insulation=Insulation.Insulation
LEFT JOIN Klasse
ON NordhavnGenset.Class=Klasse.Class
LEFT JOIN AirInletFilter
ON NordhavnGenset.AirInletFilter=AirInletFilter.AirInletFilter
LEFT JOIN IP
ON NordhavnGenset.Ip=IP.IP
WHERE (NordhavnGenset.MaxKva='46') and (Generator.Alternator='ECP34-1LN/4') and (Insulation.Insulation='F (90ºC/45ºC)') and (Klasse.Klasse='KRS\r') and (AirInletFilter.AirInletFilter='No') and (IP.IP='IP23');
It does not appear that you are Joining on a table called Generator
. You cannot have the table in your WHERE
clause unless you JOIN
on it.
If you add a JOIN
to Generator
then you can use it in the WHERE
clause.
SELECT *
FROM Scania
LEFT JOIN NordhavnGenset
ON Scania.GensetType=NordhavnGenset.Alternator
LEFT JOIN Generator
ON ....
WHERE (Generator.Alternator='ECP34-1LN/4') ...
You also have other tables in your WHERE
clause that are not JOINed
on, so you will need to add those as well.
The reason for the error is that you are not joining the tables that you are using in the WHERE
clause.
The following would always give an error -
and (Generator.Alternator='ECP34-1LN/4')
and (insulation.Insulation='F (90ºC/45ºC)')
and (Klasse.Klasse='KRS\r')
and (airinletfilter.AirInletFilter='No')
and (Ip.IP='IP23');
You either need to have the table joined or the alias of the table should be the name before the '.'.
You're not including the Generator
table in the join. Either add it, or you may mean NordhavnGenset.Alternator
instead of Generator.Alternator
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