VBA SQL语句求助

Question

我在VBA查询ACCESS中myopc表,where条件中字段mydatediff_d直接用数字就行
 "select * from myopc where mydatediff_d>=1"
如果采取下面语句
a = 1
"select * from myopc where mydatediff_d>=a"
运行时提示  运行时错误'2147217904(80040e10)'
           自动化(Automation)错误我现在需要用mydatediff_d>=a进行sql查询时,有何好办法呀,请高手帮忙!

Answer 1

字符型变量引用：
"select * from myopc where mydatediff_d>='"& a &"'"
数值型变量引用：
"select * from myopc where mydatediff_d>="& a &""

Answer 2

已知附表，表A,求表B,SQL如何写？请各位大师帮助！
Table A                                
date            line       strl                data       qty_output
2008-2-9         1          MA]噪音               2          100
2008-2-9         1         [MA]震动               3        
2008-2-10        2        [MA]流量低               5         100
2008-2-10        1        [MA]震动                 2        
2008-2-10        1        [MA]震动                 9        
2008-2-10        2        [MA]噪音                 8        
2008-2-15        2        [MA]震动                 9         100
2008-2-15        1        [G003]出油盖毛刺         10        
2008-2-17        1        [MA]流量低               11        100
2008-2-18        2        [MA]安全阀漏油           12        100
2008-2-18        2        [G002]收口变形           12        
                                
Table B                                
2008-2-9 TO 2008-2-17         qty_output   line     line          
strl                  data        300        1        2
[MA]震动                 23                   14        9
[MA]流量低               16                   11        5
[G003]出油盖毛刺         10                             10        
[MA]噪音                  8                              8