MySQL Multiple LEFT JOIN with WHERE clause

Question

这是我为连接TWO表而编写的MySQL代码，它成功地生成了我想要的新表：

SELECT 
*
FROM MarketingDb.ListingProduct ListingProduct
LEFT JOIN ErpDb.ProductListingDetail ProductListingDetail
ON ListingProduct.ProductListingId = ProductListingDetail.ProductId
WHERE ProductListingDetail.ComponentType = "S" 
LIMIT 10;

由于我实际上想加入THREE表，因此我在上面的SQL中添加了两行新代码；上面的WHERE子句是必需的b4我加入第三个表。

SELECT 
*
FROM MarketingDb.ListingProduct ListingProduct
LEFT JOIN ErpDb.ProductListingDetail ProductListingDetail
ON ListingProduct.ProductListingId = ProductListingDetail.ProductId
WHERE ProductListingDetail.ComponentType = "S" 

LEFT JOIN ErpDb.Product Product
ON Product.SKU = ProductListingDetail.ProductListingId
LIMIT 10;

但这次它失败了，错误提示说我有2行新代码的SQL语法错误。有人能帮我找出错误来解决问题吗？Thx！

Answer 1

因为Where子句必须在from子句之后，并且您将bolng全部联接到查询的from部分

制作SELECT *可以让你陷入困境，所以你可以指定你真正需要的列

SELECT 
*
FROM MarketingDb.ListingProduct ListingProduct
LEFT JOIN ErpDb.ProductListingDetail ProductListingDetail
ON ListingProduct.ProductListingId = ProductListingDetail.ProductId
LEFT JOIN ErpDb.Product Product
ON Product.SKU = ProductListingDetail.ProductListingId
WHERE ProductListingDetail.ComponentType = "S"
LIMIT 10;