我用mysql连接器连接visual basic和mysql,我用3个表进行mysql查询,我试着用inner join和normal mode,normal mode不是唯一的表/别名,inner join,datagrid不加载任何东西,这3个表就是这个
订单(N U订单、日期、客户编号)
行订单(N_订单、产品代码、数量)
产品(产品代码、名称、价格)
带innerjoin的mysql查询是:
"SELECT c.name, COUNT( b.product_code ) AS cnt FROM order a " & _
"INNER JOIN line_order b ON a.number_order = b.number_order " & _
"INNER JOIN product c ON b.product_code = c.product_code " & _
"GROUP BY c.name " & _
"ORDER BY cnt DESC "
通常的方法是:
"SELECT product.name, COUNT( order_line.product_code ) AS cntFROM order, product, order_line where order.number_order = order_line.number_orderAND order_line.product_code = product.product_codeGROUP BY product.nameORDER BY cnt DESCLIMIT 0 , 5"
当我在phpmyadmin中运行2:mysql查询时,它工作得很好,但是当我在visual basic中运行它时,它会给我一个错误,不是唯一的表别名/顺序,我不知道该怎么做,有人能帮我吗??
最佳答案
将backticks`
放在表周围,因为它与`order`
中的保留关键字冲突。