SQL Query to update a colums from a table base on a datetime field - sql

Question

I have 2 table called tblSetting and tblPaquets.
I need to update 3 fields of tblPaquets from tblSetting base on a where clause that use a datetime field of tblPaquest and tblSetting.
The sql below is to represent what I am trying to do and I know it make no sense right now.
My Goal is to have One query to achieve this goal.
I need to extract the data from tblSettings like this
SELECT TOP(1) [SupplierID],[MillID],[GradeFamilyID] FROM [tblSettings]
WHERE [DateHeure] <= [tblPaquets].[DateHeure]
ORDER BY [DateHeure] DESC
And Update tblPaquets with this data
UPDATE [tblPaquets]
SET( [SupplierID] = PREVIOUS_SELECT.[SupplierID]
[MillID] = PREVIOUS_SELECT.[MillID]
[GradeFamilly] = PREVIOUS_SELECT.[GradeFamilyID] )
Here the table design
CREATE TABLE [tblSettings](
[ID] [int] NOT NULL,
[SupplierID] [int] NOT NULL,
[MillID] [int] NOT NULL,
[GradeID] [int] NOT NULL,
[TypeID] [int] NOT NULL,
[GradeFamilyID] [int] NOT NULL,
[DateHeure] [datetime] NOT NULL,
[PeakWetEnable] [tinyint] NULL)
CREATE TABLE [tblPaquets](
[ID] [int] IDENTITY(1,1) NOT NULL,
[PaquetID] [int] NOT NULL,
[DateHeure] [datetime] NULL,
[BarreCode] [int] NULL,
[Grade] [tinyint] NULL,
[SupplierID] [int] NULL,
[MillID] [int] NULL,
[AutologSort] [tinyint] NULL,
[GradeFamilly] [int] NULL)

Answer 1

You can do this using CROSS APPLY:
UPDATE p
SET SupplierID = s.SupplierID,
MillID = s.MillID
GradeFamilly = s.GradeFamilyID
FROM tblPaquets p CROSS APPLY
(SELECT TOP (1) s.*
FROM tblSettings s
WHERE s.DateHeure <= p.DateHeure
ORDER BY p.DateHeure DESC
) s;
Notes:
There are no parentheses before SET.
I don't recommend using [ and ] to escape identifiers, unless they need to be escaped.
I presume the query on tblSettings should have an ORDER BY to get the most recent rows.