表:combined_product_item
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pid sku quality
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1 sku1 1
1 sku2 3
1 sku3 2
2 sku1 3
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SELECT ( GROUP_CONCAT( CONCAT_WS(‘*‘,sku,quantity) SEParaTOR ‘+‘ ) ) AS relation FROM combined_product_item GROUP BY pid;
结果:
relation--------sku1*1+sku2*3+sku3*2sku1*3