Question

conn.Open()
'MsgBox("Established!!!")

cmd.Connection = conn
cmd.CommandText = "SELECT price FROM products WHERE name '" & tb_pname.Text & "'"
dr = cmd.ExecuteReader

While dr.Read
    Me.tb_price.Text = Convert.ToString(dr("price"))
End While

conn.Close()

Answer 1

您错过了姓名后的=等号

WHERE name = '" & tb_pname.Text & "'"

Answer 2

您的查询运行错误。你错过了=签名。

这是正确的查询

cmd.CommandText = "SELECT price FROM products WHERE name = '" + tb_pname.Text + "'"

Answer 3

如果您需要查询不区分大小写，则可以使WHERE upper（name）= upper（'YourString'）

cmd.CommandText = "SELECT price FROM products WHERE upper(name) = upper('" & tb_pname.Text & "')"

您也可以使用“like”运算符，其中您使用“WHERE name like'PutYourTextHere'”，因此您还可以使用％之类的通配符作为任何字符串。举个例子：名称如'％Thomson％' 会找到包含字符串'Thomson'的任何名称。

cmd.CommandText = "SELECT price FROM products WHERE name like '" & tb_pname.Text & "'"

＆＃34; name＆＃34;附近的语法错误

3 个答案: