Question

我的光标只处理第一条记录然后出来。它不会成为第二记录。可能是什么问题？以下是我的代码：

要处理的行数超过600,000。当我执行select查询时，它会向我显示正确的行数，但循环不起作用。

Delimiter $$
CREATE PROCEDURE  p_updateHistory_1()
BEGIN
DECLARE v_symbol varchar(10);
DECLARE v_pricedate date;

DECLARE done BOOL DEFAULT FALSE;
DECLARE cur1 CURSOR FOR SELECT symbol, PriceDate 
           from StockData
           where PriceDate > '2016-06-30'
           order by symbol asc, PriceDate desc;

DECLARE CONTINUE HANDLER FOR NOT FOUND SET done = TRUE;

OPEN cur1;

read_loop: LOOP
FETCH cur1 INTO v_symbol, v_pricedate;

If done THEN
    LEAVE read_loop;
END IF;

Update StockData SET
20DayTPAvg = f_TP20avg(symbol,PriceDate),
20DayMFSum = f_20DayMFSum(symbol,PriceDate),
20DayVolumeSum = f_20DayVolumeSum(symbol,PriceDate),
MFFactor = f_20DayMFSum(symbol,PriceDate)/f_20DayVolumeSum(symbol,PriceDate),
50DayHighestHigh = f_50DayHighestHigh(symbol,PriceDate),
50DayLowestLow = f_50DayLowestLow(symbol,PriceDate),
50DayFactor = ((close-f_50DayLowestLow(symbol,PriceDate))/(f_50DayHighestHigh(symbol,PriceDate)-f_50DayLowestLow(symbol,PriceDate)))*100,
20DayAvgOf50DayFactor = f_20DayAvgOf50DayFactor(symbol,PriceDate),
50DayMAvg20DayBfr = f_20DayMAvg20DayBfr(symbol,PriceDate),
20DayAvgSqCh50DMA = f_20DayAvgSqCh50DMA(symbol,PriceDate),
20dStdDevOf50DayMovAvg = SQRT(f_20DayAvgSqCh50DMA(symbol,PriceDate)),
UpperBand =  50DayMovingAvg+2*SQRT(f_20DayAvgSqCh50DMA(symbol,PriceDate)), 
LowerBand = 50DayMovingAvg-2*SQRT(f_20DayAvgSqCh50DMA(symbol,PriceDate)),
MidPointFactor = ((close-MidPoint)/(high-close))*100,
20DayAvgOfMPFactor = f_20DayAvgOfMPFactor(symbol,PriceDate)
Where symbol=v_symbol
And PriceDate=v_pricedate;

commit;

END LOOP;

CLOSE Cur1;

END $$
Delimiter ;

Answer 1

我有同样的问题。根据MariaDB文档，如果任何select语句不返回任何数据，则它将被视为“未找到”，并且根据处理程序Done变为true，因此停止获取游标。似乎您正在使用许多功能。请检查是否有任何函数返回空结果。

Answer 2

CURSORs通常是个错误。你不能简单地执行一个语句，没有游标吗？

UPDATE StockData
    SET ...
    WHERE PriceDate > '2016-06-30';

f_20DayAvgOf50DayFactor（等）是UDF还是存储函数？

需要复合INDEX

INDEX(symbol, PriceDate)

MariaDB游标循环问题

2 个答案: