怎样建立查询数据库

哥们，你建立的数据库关系了吗？
如果没有就这样处理
private sub tt()
dirm rst as new adodb.recordset
dim sql-str as string
dim str_number as string
str_number=table_A.field_1 '取得a表字段1
sql_str="select table_b.field_1 from table_b where mid(***,1,7)=' “ & str_number "'"
rst.open sql_str currentproject.connection ,adoption***,***
'rst 就是符合条件的集合





end sub