错误代码：1172。结果包含多行 [MySQL]

Question

这是我第一次在mysql中创建存储过程。

它的作用是，

first- get count of all records

second- loop through that table 1 by 1

third- compare each entry if it is a duplicate

fourth- insert duplicate in a temporary table

last- display duplicates

它在 100-200 个条目上正常工作但是在高达 500+（有时 25k）的更大记录上它抛出一条消息

Error Code: 1172. Result consisted of more than one row

我用谷歌搜索了这个问题，但 none 个（答案）帮助我解决了我的问题。

请看看我的剧本

BEGIN

DECLARE n INT DEFAULT 0;
DECLARE i INT DEFAULT 0;

DECLARE i_sku VARCHAR(255);
DECLARE i_concatenated_attributes MEDIUMTEXT;

DECLARE f_sku VARCHAR(255);
DECLARE f_offer_type VARCHAR(255);
DECLARE f_name VARCHAR(255);
DECLARE f_product_owner VARCHAR(255);
DECLARE f_listing_city VARCHAR(255);
DECLARE f_listing_area VARCHAR(255);
DECLARE f_price DOUBLE;
DECLARE f_bedrooms INT;
DECLARE f_building_size INT;
DECLARE f_land_size INT;
DECLARE f_concatenated_attributes MEDIUMTEXT;
DECLARE f_duplicate_percentage INT;

SELECT COUNT(*) FROM unit_temp_listing INTO n;
CREATE TEMPORARY TABLE IF NOT EXISTS temp_temp (dup_sku VARCHAR(255), dup_percentage INT, attribs MEDIUMTEXT);
SET i=0;
WHILE i<n DO 
    -- Get all unit listings (one by one)
    SELECT
    sku, concat_ws(',',offer_type,name,product_owner,listing_city,listing_area,price,ifnull(bedrooms,0),ifnull(building_size,0),ifnull(land_size,0)) as concatenated_attributes
INTO i_sku, i_concatenated_attributes
FROM unit_temp_listing
limit 1 offset i;
-- Compare one by one (sadla)
SELECT
    f.sku, f.offer_type, f.name, f.product_owner, f.listing_city, f.listing_area, f.price, f.bedrooms, f.building_size, f.land_size, 
    levenshtein_ratio(concat_ws(',',f.offer_type,f.name,f.product_owner,f.listing_city,f.listing_area,f.price,ifnull(f.bedrooms,0),ifnull(f.building_size,0),ifnull(f.land_size,0)),i_concatenated_attributes) as f_duplicate_percentage,
    concat_ws(',',f.offer_type,f.name,f.product_owner,f.listing_city,f.listing_area,f.price,ifnull(f.bedrooms,0),ifnull(f.building_size,0),ifnull(f.land_size,0)) as fconcatenated_attributes
INTO f_sku, f_offer_type, f_name, f_product_owner, f_listing_city, f_listing_area, f_price, f_bedrooms, f_building_size, f_land_size, f_duplicate_percentage, f_concatenated_attributes
FROM unit_temp_listing f
WHERE substring(soundex(concat_ws(',',offer_type,name,product_owner,listing_city,listing_area,price,ifnull(bedrooms,0),ifnull(building_size,0),ifnull(land_size,0))),1,10) = substring(soundex(i_concatenated_attributes),1,10) 
    AND levenshtein_ratio(concat_ws(',',offer_type,name,product_owner,listing_city,listing_area,price,ifnull(bedrooms,0),ifnull(building_size,0),ifnull(land_size,0)),i_concatenated_attributes) > 90
    AND f.sku != i_sku;
-- INSERT duplicates
IF(f_sku IS NOT NULL) THEN
    INSERT INTO temp_temp (dup_sku, dup_percentage, attribs) VALUES (f_sku, f_duplicate_percentage, f_concatenated_attributes);
    SET f_sku = null;
    SET f_duplicate_percentage = null;
    SET f_concatenated_attributes = null;
END IF;
SET i = i + 1;
END WHILE;
SELECT * FROM temp_temp;
DROP TABLE temp_temp;
End

问题是什么？

Answer 1

各位开发者大家好我已经解决了我的问题，我想在这里分享它。

问题是，我在 WHILE 循环中的 SECOND SELECT 语句返回多行。我尝试使用 CURSOR 但我仍然收到错误消息。所以我试着把我的第二个 SELECT 语句放在 INSERT 语句中，像这样

INSERT INTO table_name (columns, ...) SELECT_STATEMENT

然后，问题就解决了！但是，如果这里有人有优化我的查询的想法，请帮助我。我必须处理 20k+ 条记录，但由于执行时间太长，我只接受 500 条记录 15-20 分钟。

感谢您的 18 次浏览（在撰写本文时）。

编码愉快！

错误代码：1172。结果包含多行 [MySQL]

Error Code: 1172. Result consisted of more than one row [MySQL]

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