如果数据库中已存在值，则 R 跳到下一条记录

Question

我正在用头撞墙试图解决这个问题...我有一个脚本，如果 game_id 已经存在于 table 我正在写信给我想跳到循环中的下一条记录

  #Connect to db
saber <- odbcConnect("sabermetrics")

  #query to pull all existing game records
check_query <- paste0("select distinct game_id from allbats")

  #build variables to compare db field and game_id in current url
game_id_check <- sqlQuery(saber, check_query)
curr_gameid <- substr(thisboxscoreURL, 66, 95)

  #if they match sktip to next record
if(game_id_check == curr_gameid) next

我试过矩阵化数据、列出、取消列出、组合以将数据获取到 "match"，但到处都惨遭失败！

我可能会将 url 中的 game_id 放在查询字符串的 where 子句中，如果计数大于 0，则也跳到下一条记录。我不确定哪个更好，可能是后者，因为对于循环中的每条记录，我最多只 return 一个值。

类似

  #Connect to db
saber <- odbcConnect("sabermetrics")

  #query to pull all existing game records
check_query <- paste0("select distinct game_id from allbats where game_id = url_game_id")

if(count(sqlquery(saber, check_query)))>0 next

示例数据

away    home    inning  away_team_code  home_team_code  game_id

0         0       1        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         0       2        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         0       3        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         0       4        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         1       5        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         0       6        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         0       7        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         0       8        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1
0         x       9        sdn            sfn           gid_2016_04_26_sdnmlb_sfnmlb_1

这是输出，但不确定它是否有用。

dput(sqlQuery(saber, "SELECT TOP 20 * FROM allbats"))
structure(list(away = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 5L, 0L, 1L, 0L, 0L, 0L), home = structure(c(1L, 
1L, 1L, 1L, 2L, 1L, 1L, 1L, 4L, 3L, 1L, 1L, 2L, 1L, 1L, 1L, 1L, 
1L, 1L, 1L), .Label = c("0", "1", "2", "x"), class = "factor"), 
inning = c(1L, 2L, 3L, 4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L, 3L, 
4L, 5L, 6L, 7L, 8L, 9L, 1L, 2L), away_team_code = structure(c(3L, 
3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 1L, 1L), .Label = c("hou", "mia", "sdn"), class = "factor"), 
home_team_code = structure(c(3L, 3L, 3L, 3L, 3L, 3L, 3L, 
3L, 3L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L, 2L), .Label = c("lan", 
"sea", "sfn"), class = "factor"), game_id = structure(c(3L, 
3L, 3L, 3L, 3L, 3L, 3L, 3L, 3L, 2L, 2L, 2L, 2L, 2L, 2L, 2L, 
2L, 2L, 1L, 1L), .Label = c("gid_2016_04_26_houmlb_seamlb_1", 
"gid_2016_04_26_miamlb_lanmlb_1", "gid_2016_04_26_sdnmlb_sfnmlb_1"
), class = "factor")), .Names = c("away", "home", "inning", 
"away_team_code", "home_team_code", "game_id"), row.names = c(NA, 
20L), class = "data.frame")

如有任何帮助，我们将不胜感激！！谢谢！

Answer 1

我找到了使用 sqldf 包的方法

saber <- odbcConnect("sabermetrics")

existingGames <- paste0("select distinct game_id from linescore")
newGames <- data.frame(gameids)

existingGames <- sqlQuery(saber, existingGames)

require(sqldf)

  # Get all new games that do not exist in existing games (linescore table)
ngNotIneg <- sqldf('SELECT distinct * FROM newGames EXCEPT SELECT distinct * FROM existingGames')

odbcClose(saber)

如果数据库中已存在值，则 R 跳到下一条记录

R Skip to Next Record if Value Already Exists in Database

sql-server

for-loop

r

rodbc