Question

我正在尝试在特定时间范围内查询Access数据库以查找结果。在我查询时，我想自动在输出中添加一列，指定数据所属的周（从几周开始）。通过将参数传递给select语句生成automagic列。我一直在两个错误之间来回走动，我无法弄清楚原因。

错误1）参数太少。

错误2）JOIN中的语法错误

我的python代码：

错误1代码：

qry = '''
    SELECT [PreQuery].[defect], SUM([PreQuery].[qty_rej] + [PreQuery].[qty_rew]) AS [qty_defect], ? AS [wk_no]
    FROM (
        SELECT [Sort].[Date of Sort] AS [srt_date], [Part].[Part Name] AS [prt_no], [Defect Table].[Defect2] AS [defect], [Defect Table].[Quantity Rejected] AS [qty_rej], [Defect Table].[Quantity Reworked] AS [qty_rew]
        FROM (([Defect Table] LEFT JOIN [Sort] ON [Defect Table].[Sort Number] = [Sort].[Sort Number]) LEFT JOIN [Part] ON [Sort].[Part Number] = [Part].[Part Number])) AS PreQuery LEFT JOIN [Defects] ON [Defects].[Defect Code] = [PreQuery].[Defect2]
    WHERE (([Sort].[Date of Sort] BETWEEN ? AND ?) AND ([Part].[Part Name] LIKE ? & '_TZ______'))
    GROUP BY [defect], [wk_no];'''

引发以下错误：

pyodbc.Error: ('07002', '[07002] [Microsoft][ODBC Microsoft Access Driver] Too few parameters. Expected 8. (-3010) (SQLExecDirectW)')

从[排序]中删除别名。[排序日期]和[部件]。[部件名称]再现相同的错误，但驱动程序需要 6 参数而不是 8 和以前一样。在任何一种情况下，整个语句中只有四个？，所以DB应该期待4个参数。

错误2代码：

qry = '''
    SELECT ? AS [wk_no], [defect], SUM([qty_rej] + [qty_rew]) AS [qty_defect]
    FROM (
        SELECT [Sort].[Date of Sort], [Part].[Part Name], [Defect Table].[Defect2] AS [defect], [Defect Table].[Quantity Rejected] AS [qty_rej], [Defect Table].[Quantity Reworked] AS [qty_rew]
        FROM (([Defect Table] LEFT JOIN [Sort] ON [Defect Table].[Sort Number] = [Sort].[Sort Number])
        LEFT JOIN [Part] ON [Sort].[Part Number] = [Part].[Part Number]))
    LEFT JOIN [Defects] ON [Defects].[Defect Code] = [Defect Table].[Defect2]
    WHERE (([Sort].[Date of Sort] BETWEEN ? AND ?) AND ([Part].[Part Name] LIKE ? & '_TZ______'))
    GROUP BY [defect], [wk_no];'''

这引起了：

pyodbc.ProgrammingError: ('42000', '[42000] [Microsoft][ODBC Microsoft Access Driver] Syntax error in JOIN operation. (-3510) (SQLExecDirectW)')

我自己检查了内部select语句，它在任何一种情况下执行都很好。此外，我无法看到任何明显的语法错误（PyCharm也无法使用MySQL方言进行检查）。

Answer 1

总的来说，两次查询尝试都有几个问题：

将文字'_TZ______'连接到您的上一个参数值，因为占位符?必须独立存在。
您需要为派生表 PreQuery 分配一个表别名，就像在第一次查询中一样。
JOIN必须位于新列别名缺陷，而不是缺陷2 。
在子查询中移动WHERE子句。
删除GROUP BY中的 wk_no ，因为它不是实际字段。常量不需要GROUP BY。

考虑使用表别名进行下面的语法调整，以减少长度和可读性。当然没有数据，我无法充分测试。因此，您可能需要进一步调整：

qry = """
    SELECT ? AS [wk_no], [defect], SUM([qty_rej] + [qty_rew]) AS [qty_defect]
    FROM
      (
        SELECT s.[Date of Sort], p.[Part Name], d.[Defect2] AS [defect], 
               d.[Quantity Rejected] AS [qty_rej], d.[Quantity Reworked] AS [qty_rew]
        FROM (([Defect Table] d LEFT JOIN [Sort] s ON d.[Sort Number] = s.[Sort Number])
               LEFT JOIN [Part] p ON s.[Part Number] = p.[Part Number])
        WHERE ((s.[Date of Sort] BETWEEN ? AND ?) AND (p.[Part Name] LIKE ?))
      ) As PreQuery
    LEFT JOIN [Defects] ON [Defects].[Defect Code] = [PreQuery].[defect]        
    GROUP BY [defect];
"""   

cursor.execute(qry, myparams)  # WHERE LAST PARAM HAS '_TZ______' CONCATENATED TO ORIG VALUE

带有MS Access的pyodbc期望参数太多

1 个答案: