SQL Server：创建并调用存储过程

Question

如何正确写这个？

我正在编写一个将采用（StockName, NewOpenPrice, NewClosePrice）的存储过程，并向表中添加一条新记录（如图所示），如果stockname不存在则。如果库存名称为EXIST，则OpenPrice和ClosePrice将使用新插入的价格进行更新。最后我想调用存储过程

这就是现在的样子

CREATE PROCEDURE p_updatestock
    (
    @StockName VARCHAR(50), 
    @OpenPrice MONEY,
    @ClosePrice MONEY)
AS
    Declare @NewOpenPrice MONEY
    Declare @NewClosePrice MONEY

    UPDATE Stocks 
    SET StockName = @StockName
    SET @StockName = @rowcount

    UPDATE Stocks 
    SET NewOpenPrice = @NewOpenPrice
    WHERE OpenPrice = @NewOpenPrice 
    SET @NewOpenPrice = @rowcount

    IF (@StockName EXIST THEN OpenPrice)
        UPDATE Stocks 
        SET NewClosePrice = @NewClosePrice
        WHERE ClosePrice = @NewClosePrice
        SET @NewClosePrice = @rowcount

        IF (@StockName EXIST THEN ClosePrice)

Answer 1

我认为这就是你需要的

CREATE PROCEDURE P_updatestock (@StockName  VARCHAR(50),
                                @OpenPrice  MONEY,
                                @ClosePrice MONEY)
AS
  BEGIN
      IF EXISTS (SELECT 1
                 FROM   Stocks
                 WHERE  StockName = @StockName)
        UPDATE Stocks
        SET    ClosePrice = @ClosePrice,
               Openprice = @Openprice
        WHERE  StockName = @StockName
      ELSE
        INSERT INTO stocks
                    (StockName,
                     Openprice,
                     ClosePrice)
        VALUES      (@StockName,
                     @Openprice,
                     @ClosePrice)
  END 

或使用Merge代替If-Else

MERGE Stocks AS target
USING (SELECT @StockName,
              @OpenPrice,
              @ClosePrice) AS source (StockName, OpenPrice, ClosePrice)
ON ( target.StockName = source.StockName )
WHEN MATCHED THEN
  UPDATE SET ClosePrice = source.ClosePrice,
             Openprice = source.Openprice
WHEN NOT MATCHED THEN
  INSERT (StockName,
          Openprice,
          ClosePrice)
  VALUES (source.StockName,
          source.Openprice,
          source.closeprice) 

执行

  exec P_updatestock 'PFE',22.34,32.45