VBA + ADO 调用存储过程

最近对 pandas, Power Query 和 SQL 的数据处理和加工进行了一些类似的处理，希望通过比较看到各种处理方式的优点。之前笔者用的比较多的是 VBA + ADO，VBA + ADO 的方式其实离不开 Sql 语句，这种方式也有非常方便：前台有 Excel，后台有数据库就能实现。

由于 VBA 对多行字符串的支持不好，代码中表达 sql 语句极不方便，所利用数据库的存储过程，将sql 语句放在存储过程中。这样，代码中只关心存储过程的名称和参数，代码大大简化，并且利用了数据库的计算能力，性能得到提高。本文介绍在 VBA 中利用 ADO 如何操作存储过程的要点。

调用 SQL Server 存储过程

连接字符串

ADO 连接到数据库，需要连接字符串。在 Windows 上连接到数据库，可以利用数据库连接向导，帮助构建连接字符串，不用死记。方法如下：在任意位置新建一个扩展名为 udl 的文件，然后双击 udl 文件，启动数据库连接向导。假设需要连接到 SQL Server 数据库，首先选择数据库驱动：

点击下一步按钮，输入数据库服务器名称和登录的方式：

点击测试连接按钮，测试是否连接成功。没有问题，点击确定按钮完成。然后用可以打开文本文件的编辑器打开 udl 文件，文件保存的就是我们需要的连接字符串。

[oledb]
; Everything after this line is an OLE DB initstring
Provider=SQLOLEDB.1;Integrated Security=SSPI;
Persist Security Info=False;
Initial Catalog=stonetest;
Data Source=STONEWM-PC\SQLEXPRESS

在 sql server 中创建存储过程

本例设计的场景是在存储过程中计算物料在某个月份的进出存数据。sql 语句可以用子查询或者 Common Table Expression。完成后的存储过程代码如下：

CREATE PROCEDURE [dbo].[spGetStockBalances]
	@y int,
	@m int
AS
	BEGIN
		WITH merged AS (
			SELECT
				d.DocNo,
				d.MaterialNo,
				d.Qty,
				h.MovementType,
				h.DocDate,
				t.InOutSign,
				YEAR(h.DocDate) AS TxYear,
				MONTH(h.DocDate) AS TxMonth,
				CASE InOutSign WHEN '+' THEN ISNULL(d.Qty, 0) else -1 * ISNULL(d.Qty, 0) END AS ActualQty
			FROM
				stock_movement_details d
				INNER JOIN stock_movement_headers h ON d.DocNo = h.DocNo
				LEFT OUTER JOIN movement_types t ON h.MovementType = t.MovementTypeID
		),
		calculated AS (
			SELECT
				MaterialNo,
				InOutSign,
				TxYear,
				TxMonth,
				ActualQty,
				CASE WHEN TxYear < @y
				OR (
					TxYear = @y
					AND TxMonth < @m
				) THEN ActualQty ELSE 0 END AS BeginQty,
				CASE WHEN TxYear = @y
				AND TxMonth = @m
				AND InOutSign = '+' THEN ActualQty ELSE 0 END AS StockIn,
				CASE WHEN TxYear = @y
				AND TxMonth = @m
				AND InOutSign = '-' THEN ActualQty ELSE 0 END AS StockOut
			FROM
				merged
		)
		SELECT
			MaterialNo,
			SUM(BeginQty) AS BeginQty,
			SUM(StockIn) AS StockIn,
			SUM(StockOut) AS StockOut,
			SUM(BeginQty+StockIn+StockOut) AS EndQty
		FROM
			calculated
		GROUP BY
			MaterialNo;
	END;

存储过程中有两个变量 @y 表示年度，@m 表示月份。

VBA 调用 SQL Server 存储过程

在 VBE 环境中，添加对 Microsoft ActiveX Data Objects 对象的引用，然后编写如下代码：

Option Explicit

Public Sub GetStockBalance()
    Dim conn As New ADODB.Connection
    Dim cmd As New ADODB.Command
    
    conn.ConnectionString = "Provider=SQLOLEDB.1;" & _
        "Integrated Security=SSPI;Persist Security Info=False;" & _
        "Initial Catalog=stonetest;Data Source=STONEWM-PC\SQLEXPRESS"
    conn.Open
        
    With cmd
        .ActiveConnection = conn
        .CommandType = adCmdStoredProc
        .CommandText = "dbo.spGetStockBalances"
        .Parameters.Append .CreateParameter("@y", adInteger, adParamInput, , 2008)
        .Parameters.Append .CreateParameter("@m", adInteger, adParamInput, , 4)
    End With
    
    Dim rs As New ADODB.Recordset
    Set rs = cmd.Execute
    
    ' headers
    Dim col As Integer
    Dim startCell As Range
    col = 0
    Set startCell = Sheet1.Range("A1")
    For col = 0 To rs.Fields.Count - 1
        startCell.Offset(0, col).Value = rs.Fields(col).Name
    Next
    ' lines
    startCell.Offset(1, 0).CopyFromRecordset rs
    
    rs.Close
    conn.Close
    
    Set rs = Nothing
    Set cmd = Nothing
    Set conn = Nothing
End Sub

调用 MySQL 存储过程

配置 ODBC 数据源

ADO 连接 MySQL 数据库，使用 ODBC 数据源。在 Windows 的 Run 窗口中输入 odbcad32 命令，打开配置连接界面。确保已经下载和安装 ODBC for MySQL 驱动程序：

然后在界面中配置数据源：

编写存储过程

MySQL 的存储过程与 T-SQL 语法有一些区别，包括不支持 CTE，所以需要用子查询来解决嵌套调用。

DELIMITER $$
CREATE DEFINER=`root`@`localhost` PROCEDURE `spStockBalances`(
	y int,
    m int
)
BEGIN
	SELECT
		MaterialNo,
		SUM(BeginQty) AS BeginQty,
		SUM(StockIn) AS StockIn,
		SUM(StockOut) AS StockOut,
		SUM(BeginQty+StockIn+StockOut) AS EndQty
	FROM
		(
			SELECT
				MaterialNo,
				TxYear,
				TxMonth,
				InOutSign,
				ActualQty,
				CASE WHEN (TxYear < y)
				OR (
					TxYear = y
					AND TxMonth < m
				) THEN ActualQty ELSE 0 END AS BeginQty,
				CASE WHEN TxYear = y
				AND TxMonth = m
				AND InOutSign = '+' THEN ActualQty ELSE 0 END AS StockIn,
				CASE WHEN TxYear = y
				AND TxMonth = m
				AND InOutSign = '-' THEN ActualQty ELSE 0 END AS StockOut
			FROM
				(
					SELECT
						d.MaterialNo,
						d.Qty,
						h.MovementType,
						h.DocDate,
						t.InOutSign,
						YEAR(h.DocDate) AS TxYear,
						MONTH(h.DocDate) AS TxMonth,
						CASE WHEN t.InOutSign = '+' THEN ifnull(d.Qty, 0) ELSE -1 * ifnull(d.Qty,0) END AS ActualQty
					FROM
						stock_movement_details AS d
						INNER JOIN stock_movement_headers AS h ON d.DocNo = h.DocNo
						LEFT JOIN movement_types AS t ON h.MovementType = t.MovementTypeID
				) AS joined
		) AS calculated
	GROUP BY
		MaterialNo
	ORDER BY
		MaterialNo;
END$$
DELIMITER ;

调用 MySQL 存储过程

根据测试，用 Command 命令创建参数并调用存储过程的结果不正确，所以直接用 Recordset Open 方法能返回正确的结果。

Option Explicit

Public Sub GetStockBalance()
    Dim conn As New ADODB.Connection    
    Dim connStr As String
    connStr = "DRIVER={MySQL ODBC 8.0 Unicode Driver}; " & _
        "SERVER=localhost; PORT=3306; DATABASE=stonetest; USER=root; PASSWORD=pwd;OPTIONS=3"
    
    conn.ConnectionString = connStr
    conn.Open
    
    Dim rs As New ADODB.Recordset
    rs.Open "call spStockBalances(2008,4)", conn, adOpenStatic, adLockReadOnly
        
    ' headers
    Dim col As Integer
    Dim startCell As Range
    col = 0
    Set startCell = Sheet1.Range("A1")
    For col = 0 To rs.Fields.Count - 1
        startCell.Offset(0, col).Value = rs.Fields(col).Name
    Next
    ' lines
    startCell.Offset(1, 0).CopyFromRecordset rs
    
    ' clean up
    rs.Close
    conn.Close
    Set rs = Nothing
    Set conn = Nothing
End Sub