SQL查詢變量

Question

我有一個查詢特定股票交易數據的sql查詢。我正試圖通過不同的股票來應用特定的分析。下面的代碼顯示了我試圖將循環中的查詢以及「硬編碼」查詢傳遞給變量。

任何指導將不勝感激。

my.stocks <- c('ABL','IPL') 

for (i in 1:2) 
{ 
channel <- odbcConnect("Public_Trades") 
my.frame1 <- sqlQuery(channel, 
"SELECT TRADE_DATE_TIME, 
PRICE, 
QUANTITY 
FROM [ISLDWODS].[HERMES_PUBLIC].[PUBLIC_TRADES_HISTORY] 
where TRADE_DATE_TIME > '2012-11-01' and TRADE_TYPE ='AT' and INSTR_CODE = " & my.stocks[i] & 
"order by TRADE_DATE_TIME asc") 

my.frame2 <- sqlQuery(channel, 
"SELECT TRADE_DATE_TIME, 
PRICE, 
QUANTITY 
FROM [ISLDWODS].[HERMES_PUBLIC].[PUBLIC_TRADES_HISTORY] 
where TRADE_DATE_TIME > '2012-11-01' and TRADE_TYPE in ('AT','UT') and INSTR_CODE = 'MPC' 
order by TRADE_DATE_TIME asc") 


close(channel) 
} 

Answer 1

感謝sgibb，

膏可以解決該問題：？

my.stocks <- c("'ABL'","'IPL'") 


for (i in 1:2) 
{ 

my.string1 <- paste("SELECT TRADE_DATE_TIME,PRICE,QUANTITY 
       FROM [ISLDWODS].[HERMES_PUBLIC].[PUBLIC_TRADES_HISTORY] 
       where TRADE_DATE_TIME > '2012-11-01' and TRADE_TYPE ='AT' and INSTR_CODE = ", my.stocks[1]," order by TRADE_DATE_TIME asc") 

my.string2 <- paste("SELECT TRADE_DATE_TIME,PRICE,QUANTITY 
       FROM [ISLDWODS].[HERMES_PUBLIC].[PUBLIC_TRADES_HISTORY] 
       where TRADE_DATE_TIME > '2012-11-01' and TRADE_TYPE in ('AT','UT') and INSTR_CODE = ", my.stocks[1]," order by TRADE_DATE_TIME asc") 

channel <- odbcConnect("Public_Trades") 
my.frame1 <- sqlQuery(channel,my.string1) 

my.frame2 <- sqlQuery(channel,my.string2) 
}