i cant update to datetime table - sql

Question

i have already have date value
SET #LogDate1 = CAST(#logtanggal AS datetime)
SET #LogDate = CONVERT(varchar, #LogDate1, 20 )
#logtanggal is varchar, and i already convert it to datetime, the problem is when i try to update value of #logdate to the table, there are error mssg like
Msg 241, Level 16, State 1, Procedure LockAmountOnline_t24_Active, Line 108
Conversion failed when converting date and/or time from character string.
the table data type is already datetime, why i cant update to table?
the update query
SET #sql1 = 'UPDATE Lock_Amount_Trx
SET
GenerateDate = GETDATE(), -- datetime
LogDate ='''+#Logdate1+''', -- datetime
LogStatus = CASE WHEN tlat.logdescription = ''SUCCESS.UPD'' THEN ''SUCCESS''
WHEN tlat.logdescription = ''NOT.UPD-KTA'' THEN ''NOT CHANGED''
END ,
LogDescription = tlat.logdescription -- varchar
FROM ##TempLockAmmountTrx tlat, Lock_Amount_Trx lat
WHERE tlat.cuscode = lat.Custcode AND tlat.norekdeb = lat.NoRekDebet AND tlat.lockammount = lat.TotalLockAmount AND lat.Id ='''+ #idFile +''''
EXEC (#sql1)
converted varchar(top) and target table date format date (bottom)

Answer 1

There is literally no need for "dynamic" SQL here, there's nothing dynamic in your code. All you are doing here is creating a huge security flaw in your code. SQL injection is not a good thing, and you should never write code that can suffer from it.
Stop using dynamic SQL and the error doesn't happen:
UPDATE Lock_Amount_Trx
SET GenerateDate = GETDATE(), -- datetime
LogDate = #Logdate1, -- datetime
LogStatus = CASE WHEN tlat.logdescription = 'SUCCESS.UPD' THEN 'SUCCESS'
WHEN tlat.logdescription = 'NOT.UPD-KTA' THEN 'NOT CHANGED'
END,
LogDescription = tlat.logdescription -- varchar
FROM ##TempLockAmmountTrx tlat, Lock_Amount_Trx lat
WHERE tlat.cuscode = lat.Custcode
AND tlat.norekdeb = lat.NoRekDebet
AND tlat.lockammount = lat.TotalLockAmount
AND lat.Id = #idFile;
If you do ever need to actually use dynamic SQL, I suggest reading up on some of the basics, such as properly quoting your dynamic objects (which the above has none), and parametrising your statements. Rather than putting this all in the answer (which, considering that you don't need dynamic SQL, means it's not really really), you can read about this in my article Dos and Don'ts of Dynamic SQL.
Also, be very careful with your expression CONVERT(varchar, #LogDate1, 20 ). Always declare your length, scale and precissions when using data types.

Answer 2

You need to use parameterized Dynamic SQL :
SET #sql1 = 'UPDATE Lock_Amount_Trx
SET
GenerateDate = GETDATE(), -- datetime
LogDate = #LogDate1, -- datetime
LogStatus = CASE WHEN tlat.logdescription = ''SUCCESS.UPD'' THEN ''SUCCESS''
WHEN tlat.logdescription = ''NOT.UPD-KTA'' THEN ''NOT CHANGED''
END ,
LogDescription = tlat.logdescription -- varchar
FROM ##TempLockAmmountTrx tlat, Lock_Amount_Trx lat
WHERE tlat.cuscode = lat.Custcode AND tlat.norekdeb = lat.NoRekDebet AND tlat.lockammount = lat.TotalLockAmount AND lat.Id = #idFile'
exec sp_executesql #sql1, N'#LogDate1 DATETIME, #idFile varchar(255)', #LogDate1, #idFile
Note : I don't know what is the type of idfile so, change the type accordingly.
EDIT : As larnu pointed out that this query will not require any Dynamic SQL.
So, you can use plain update statement.