VBA ADODB SQL 查询 returns "Automation error" 从单元格读取变量时，在 VBA 代码中赋值时效果很好

Question

调试器 returns 自动化错误运行以下 :

Private Sub setDB()

Dim SQL As String
Dim Var As String

Dim conn As ADODB.Connection
Set conn = New ADODB.Connection

conn.Open "DRIVER={MariaDB ODBC 3.0 Driver}" _
& ";SERVER=" & "localhost" _
& ";DATABASE=" & "pbx" _
& ";USER=" & "root" _
& ";PASSWORD=" & "r00t" _

Var = Worksheets(3).Range("B2").Value  

SQL = "UPDATE ps_product SET ean13='" & Var & "' WHERE id_product=12"
conn.Execute (SQL)

然而，当我像这样给 Var 赋值时：Var=10，代码运行正常。我在这里错过了什么吗？我在互联网上搜索了几天，但没有找到类似的东西。有人可以帮助或发送 link 到类似的问题吗？

Answer 1

当所需的单元格作为参数传递时，查询正在运行。（感谢@Parfait 的提示）可以在这里找到一些帮助我解决这个问题的有用信息：

VBA, ADO.Connection and query parameters https://docs.microsoft.com/en-us/sql/ado/guide/data/creating-and-executing-a-simple-command?view=sql-server-ver15 https://docs.microsoft.com/en-us/sql/ado/guide/data/passing-parameters-to-a-named-command?view=sql-server-ver15

Working example:

Private Sub setDB()

Dim Cm As New ADODB.Command
Dim Rs As New ADODB.Recordset

Dim conn As ADODB.Connection
Set conn = New ADODB.Connection

Test = Worksheets(3).Range("B2").Value

CommandText = "UPDATE ps_product SET ean13=? WHERE id_product=12;"

conn.Open "DRIVER={MariaDB ODBC 3.0 Driver}" _
& ";SERVER=" & "localhost" _
& ";DATABASE=" & "pbx" _
& ";USER=" & "root" _
& ";PASSWORD=" & "r00t" _

Cm.CommandText = CommandText
Cm.CommandType = adCmdText
Cm.Name = "Var"
Set Cm.ActiveConnection = conn

conn.Var Test, Rs

End Sub

Answer 2

考虑参数化，这是将应用层值绑定到已执行 SQL 查询的首选方法。 ADO 通过 Command parameters 支持这种方法。如果字符串值包含单引号等特殊字符，这可以避免混乱的连接、引号标点符号和转义需求。

Dim Sql As String, Var As String

Dim conn As ADODB.Connection
Dim cmd As ADODB.Command              ' NEW OBJECT TO INITIALIZE

Set conn = New ADODB.Connection

conn.Open "DRIVER={MariaDB ODBC 3.0 Driver}" _
           & ";SERVER=" & "localhost" _
           & ";DATABASE=" & "pbx" _
           & ";USER=" & "root" _ 
           & ";PASSWORD=" & "r00t" _

' PREPARED STATEMENT WITH PLACEHOLDER (NO QUOTES OR CONCATENATION)
Sql = "UPDATE ps_product SET ean13=? WHERE id_product=12"  

' CONVERT TO NEEDED TYPE 
Var = CStr(Worksheets(3).Range("B2").Value)

Set cmd = New ADODB.Command

With cmd
    .ActiveConnection = conn
    .CommandText = Sql
    .CommandType = adCmdText

    ' BIND PARAMS AND DEFINE TYPE AND LENGTH
    .Parameters.Append .CreateParameter("prm", adVarChar, adParamInput, 255, Var)

    ' EXECUTE ACTION
    .Execute
End cmd

VBA ADODB SQL 查询 returns "Automation error" 从单元格读取变量时，在 VBA 代码中赋值时效果很好

VBA ADODB SQL query returns "Automation error" when reading a variable from cell, works well when a value is assigned in VBA code

sql

vba

adodb

mariadb

sql-update