以前没写过ON DUPLICATE KEY UPDATE，写了一个插入更新，写错了，把ON DUPLICATE KEY UPDATE写在for循环里，也没写values，不知道为啥之前没测试出来，赶紧记录一下

错误：

  <foreach collection="list" index="index" item="item" separator=",">
            ( #{item.groupNum},#{item.organizeId}, #{item.taxTime}, #{item.periodTax}, #{item.invoicePeriodTax},
            #{item.purchaseTaxDeduction}, #{item.taxDeductionForPurchaseTax}, #{item.vatDeclaration}, #{item.purchaseTaxCurrentAmount},
            #{item.gmtCreate}, #{item.gmtModified} )
            ON DUPLICATE KEY UPDATE period_tax = #{item.periodTax}, invoice_period_tax = #{item.invoicePeriodTax},
            purchase_tax_deduction = #{item.purchaseTaxDeduction}, tax_deduction_for_purchase_tax = #{item.taxDeductionForPurchaseTax},
            vat_declaration = #{item.vatDeclaration},
            purchase_tax_current_amount = #{item.purchaseTaxCurrentAmount};
        </foreach>

错误点：第一，不应该写在for循环里，第二没写values，第三等于后是写表字段

正确：

 <foreach collection="list" index="index" item="item" separator=",">
            ( #{item.groupNum},#{item.organizeId}, #{item.taxTime}, #{item.periodTax}, #{item.invoicePeriodTax},
            #{item.purchaseTaxDeduction}, #{item.taxDeductionForPurchaseTax}, #{item.vatDeclaration}, #{item.purchaseTaxCurrentAmount},
            #{item.gmtCreate}, #{item.gmtModified} )
        </foreach>
        ON DUPLICATE KEY UPDATE
        period_tax = VALUES (period_tax), invoice_period_tax = VALUES (invoice_period_tax),
        purchase_tax_deduction = VALUES (purchase_tax_deduction), tax_deduction_for_purchase_tax = VALUES (tax_deduction_for_purchase_tax),
        vat_declaration = VALUES (vat_declaration),
        purchase_tax_current_amount = VALUES (purchase_tax_current_amount);

period_tax = VALUES (period_tax), 

这种格式的，参考：https://www.cnblogs.com/zjdxr-up/p/8319982.html