CODEWITHSUNDEEP
vb.net
moji
moji

Reputation: 63

Conversion from string to type Double is not valid

I want to add a value to a field that has value from before. My code is:

Dim Credits As Integer = Int64.Parse(FinalPay.ToString)
Dim cmd As New SqlCommand("Update Users Set Credit=Credit+" + Credits + 
                          " Where Email ='" + UserEmail + "'", con)

But I get an error that says:

"Conversion from string to double is not valid"

Upvotes: 1

Views: 2414

Answers (2)

sapi
sapi

Reputation: 244

Dim Credits As Integer = Int64.Parse(FinalPay.ToString)
Dim cmd As New SqlCommand("Update Users Set Credit=Credit+" & Credits & 
                                                " Where Email ='" & UserEmail & "'", con)

When you want to concat a string in vb you want to use the "&" operator

Upvotes: -2

Andrew Morton
Andrew Morton

Reputation: 25013

If you use SQL parameters it should work correctly:

Dim cmd As New SqlCommand("UPDATE Users SET Credit = Credit + @Credits Where Email = @Email", con)
cmd.Parameters.Add(New SqlParameter With {.ParameterName = "@Credits", .SqlDbType = SqlDbType.Int, .Value = finalPay})
cmd.Parameters.Add(New SqlParameter With {.ParameterName = "@Email", .SqlDbType = SqlDbType.NVarChar, .Size = 256, .Value = userEmail})

Adjust each parameter type (and size) to match the declarations in the database.

Upvotes: 3

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