library(tidyverse)
## -- Attaching packages -------------------------------------------- tidyverse 1.3.0 --
## v ggplot2 3.3.2     v purrr   0.3.4
## v tibble  3.0.3     v dplyr   1.0.1
## v tidyr   1.1.1     v stringr 1.4.0
## v readr   1.3.1     v forcats 0.5.0
## -- Conflicts ----------------------------------------------- tidyverse_conflicts() --
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()
library(RSQLite)
library(DBI)
library(RSQL)
library(dbplyr)
## 
## Attaching package: 'dbplyr'
## The following objects are masked from 'package:dplyr':
## 
##     ident, sql
library(dplyr)
library(odbc)

Getting to Know the Data

# R has trouble guessing some column types, so we explicitly tell it 
# the types of the problem columns
log <- read_csv("game_log.csv", 
                col_types = cols(.default = "c",
                                 v_league = "c", h_league = "c",
                                 `3b_umpire_id` = "c", `3b_umpire_name` = "c",
                                 `2b_umpire_id` = "c", `2b_umpire_name` = "c",
                                 `lf_umpire_id` = "c", `lf_umpire_name` = "c",
                                 `rf_umpire_id` = "c", `rf_umpire_name` = "c",
                                 completion = "c", winning_rbi_batter_id = "c",
                                 winning_rbi_batter_id_name = "c", protest = "c",
                                 v_first_catcher_interference = "c", 
                                 h_first_catcher_interference = "c"))
head(log)
## # A tibble: 6 x 161
##   date  number_of_game day_of_week v_name v_league v_game_number h_name h_league
##   <chr> <chr>          <chr>       <chr>  <chr>    <chr>         <chr>  <chr>   
## 1 1871~ 0              Thu         CL1    <NA>     1             FW1    <NA>    
## 2 1871~ 0              Fri         BS1    <NA>     1             WS3    <NA>    
## 3 1871~ 0              Sat         CL1    <NA>     2             RC1    <NA>    
## 4 1871~ 0              Mon         CL1    <NA>     3             CH1    <NA>    
## 5 1871~ 0              Tue         BS1    <NA>     2             TRO    <NA>    
## 6 1871~ 0              Thu         CH1    <NA>     2             CL1    <NA>    
## # ... with 153 more variables: h_game_number <chr>, v_score <chr>,
## #   h_score <chr>, length_outs <chr>, day_night <chr>, completion <chr>,
## #   forefeit <chr>, protest <chr>, park_id <chr>, attendance <chr>,
## #   length_minutes <chr>, v_line_score <chr>, h_line_score <chr>,
## #   v_at_bats <chr>, v_hits <chr>, v_doubles <chr>, v_triples <chr>,
## #   v_homeruns <chr>, v_rbi <chr>, v_sacrifice_hits <chr>,
## #   v_sacrifice_flies <chr>, v_hit_by_pitch <chr>, v_walks <chr>,
## #   v_intentional_walks <chr>, v_strikeouts <chr>, v_stolen_bases <chr>,
## #   v_caught_stealing <chr>, v_grounded_into_double <chr>,
## #   v_first_catcher_interference <chr>, v_left_on_base <chr>,
## #   v_pitchers_used <chr>, v_individual_earned_runs <chr>,
## #   v_team_earned_runs <chr>, v_wild_pitches <chr>, v_balks <chr>,
## #   v_putouts <chr>, v_assists <chr>, v_errors <chr>, v_passed_balls <chr>,
## #   v_double_plays <chr>, v_triple_plays <chr>, h_at_bats <chr>, h_hits <chr>,
## #   h_doubles <chr>, h_triples <chr>, h_homeruns <chr>, h_rbi <chr>,
## #   h_sacrifice_hits <chr>, h_sacrifice_flies <chr>, h_hit_by_pitch <chr>,
## #   h_walks <chr>, h_intentional_walks <chr>, h_strikeouts <chr>,
## #   h_stolen_bases <chr>, h_caught_stealing <chr>,
## #   h_grounded_into_double <chr>, h_first_catcher_interference <chr>,
## #   h_left_on_base <chr>, h_pitchers_used <chr>,
## #   h_individual_earned_runs <chr>, h_team_earned_runs <chr>,
## #   h_wild_pitches <chr>, h_balks <chr>, h_putouts <chr>, h_assists <chr>,
## #   h_errors <chr>, h_passed_balls <chr>, h_double_plays <chr>,
## #   h_triple_plays <chr>, hp_umpire_id <chr>, hp_umpire_name <chr>,
## #   `1b_umpire_id` <chr>, `1b_umpire_name` <chr>, `2b_umpire_id` <chr>,
## #   `2b_umpire_name` <chr>, `3b_umpire_id` <chr>, `3b_umpire_name` <chr>,
## #   lf_umpire_id <chr>, lf_umpire_name <chr>, rf_umpire_id <chr>,
## #   rf_umpire_name <chr>, v_manager_id <chr>, v_manager_name <chr>,
## #   h_manager_id <chr>, h_manager_name <chr>, winning_pitcher_id <chr>,
## #   winning_pitcher_name <chr>, losing_pitcher_id <chr>,
## #   losing_pitcher_name <chr>, saving_pitcher_id <chr>,
## #   saving_pitcher_name <chr>, winning_rbi_batter_id <chr>,
## #   winning_rbi_batter_id_name <chr>, v_starting_pitcher_id <chr>,
## #   v_starting_pitcher_name <chr>, h_starting_pitcher_id <chr>,
## #   h_starting_pitcher_name <chr>, v_player_1_id <chr>, v_player_1_name <chr>,
## #   v_player_1_def_pos <chr>, ...
dim(log)
## [1] 171907    161

It looks like the game log has 170,000+ games recorded. Also it looks like these games are chronologically ordered and occur between 1871 and 2016.

For each game we have:

We have a game_log_fields.txt file that tell us that the player number corresponds with the order in which they batted.

It’s worth noting that there is no natural primary key column for this table.

person <- read_csv("person_codes.csv")
## Parsed with column specification:
## cols(
##   id = col_character(),
##   last = col_character(),
##   first = col_character(),
##   player_debut = col_character(),
##   mgr_debut = col_character(),
##   coach_debut = col_character(),
##   ump_debut = col_character()
## )
head(person)
## # A tibble: 6 x 7
##   id       last    first    player_debut mgr_debut coach_debut ump_debut
##   <chr>    <chr>   <chr>    <chr>        <chr>     <chr>       <chr>    
## 1 aardd001 Aardsma David    04/06/2004   <NA>      <NA>        <NA>     
## 2 aaroh101 Aaron   Hank     04/13/1954   <NA>      <NA>        <NA>     
## 3 aarot101 Aaron   Tommie   04/10/1962   <NA>      04/06/1979  <NA>     
## 4 aased001 Aase    Don      07/26/1977   <NA>      <NA>        <NA>     
## 5 abada001 Abad    Andy     09/10/2001   <NA>      <NA>        <NA>     
## 6 abadf001 Abad    Fernando 07/28/2010   <NA>      <NA>        <NA>
dim(person)
## [1] 20494     7

This seems to be a list of people with IDs. The IDs look like they match with IDs in the game log. There are debut dates for players, managers, coaches, and umpires.

It also looks like coaches and managers are two different things in baseball. After some research, managers are what would be called a ‘coach’ or ‘head coach’ in other sports.

park <- read.csv("park_codes.csv")
head(park)
##   park_id                          name
## 1   ALB01                Riverside Park
## 2   ALT01                 Columbia Park
## 3   ANA01      Angel Stadium of Anaheim
## 4   ARL01             Arlington Stadium
## 5   ARL02 Rangers Ballpark in Arlington
## 6   ATL01 Atlanta-Fulton County Stadium
##                                        aka      city state      start
## 1                                             Albany    NY 09/11/1880
## 2                                            Altoona    PA 04/30/1884
## 3            Edison Field; Anaheim Stadium   Anaheim    CA 04/19/1966
## 4                                          Arlington    TX 04/21/1972
## 5 The Ballpark in Arlington; Ameriquest Fl Arlington    TX 04/11/1994
## 6                                            Atlanta    GA 04/12/1966
##          end league                                          notes
## 1 05/30/1882     NL TRN:9/11/80;6/15&9/10/1881;5/16-5/18&5/30/1882
## 2 05/31/1884     UA                                               
## 3                AL                                               
## 4 10/03/1993     AL                                               
## 5                AL                                               
## 6 09/23/1996     NL
dim(park)
## [1] 252   9

This seems to be a list of all baseball parks. There are IDs which seem to match with the game log, as well as names, nicknames, city and league.

team <- read.csv("team_codes.csv")
head(team)
##   team_id league start  end      city        nickname franch_id seq
## 1     ALT     UA  1884 1884   Altoona Mountain Cities       ALT   1
## 2     ARI     NL  1998    0   Arizona    Diamondbacks       ARI   1
## 3     BFN     NL  1879 1885   Buffalo          Bisons       BFN   1
## 4     BFP     PL  1890 1890   Buffalo          Bisons       BFP   1
## 5     BL1         1872 1874 Baltimore        Canaries       BL1   1
## 6     BL2     AA  1882 1891 Baltimore         Orioles       BL2   1
dim(team)
## [1] 150   8

This seems to be a list of all teams, with team_ids that seem to match the game log.

Defensive Positions

In the game log, each player has a defensive position listed, which seems to be a number between 1-10. Doing some research around this, I found this [article] (http://probaseballinsider.com/baseball-instruction/baseball-basics/baseball-basics-positions/) which gives us a list of names for each numbered position:

  • Pitcher
  • Catcher
  • 1st Base
  • 2nd Base
  • 3rd Base
  • Shortstop
  • Left Field
  • Center Field
  • Right Field

The 10th position isn’t included, it may be a way of describing a designated hitter that does not field. I can find a retrosheet page that indicates that position 0 is used for this, but we don’t have any position 0 in our data. I have chosen to make this an ‘Unknown Position’ so I’m not including data based on a hunch.

Leagues

Wikipedia tells us there are currently two leagues - the American (AL) and National (NL). Upon investigation of the data, we see that there are actually 4 more. After some googling, we come up with:

It also looks like we have about 1000 games where the home team doesn’t have a value for league.

Importing Data Into SQLite

conn <- dbConnect(SQLite(), "mlb.db")

dbWriteTable(conn = conn, name = "game_log", 
             value = log, row.names = FALSE, header = TRUE, overwrite=TRUE)

dbWriteTable(conn = conn, name = "person_codes", 
             value = person, row.names = FALSE, header = TRUE, overwrite=TRUE)

dbWriteTable(conn = conn, name = "team_codes", 
             value = team, row.names = FALSE, header = TRUE, overwrite=TRUE)

dbWriteTable(conn = conn, name = "park_codes", 
             value = park, row.names = FALSE, header = TRUE, overwrite=TRUE)

# Confirm that all of the tables are in
dbListTables(conn)
##  [1] "appearance_type"   "game"              "game_log"         
##  [4] "games_log"         "league"            "park"             
##  [7] "park_code"         "park_codes"        "person"           
## [10] "person_appearance" "person_code"       "person_codes"     
## [13] "team"              "team_appearance"   "team_code"        
## [16] "team_codes"
# Create the new column within game_log
alter_game_log_command <- "
  ALTER TABLE game_log
  ADD COLUMN game_id TEXT;
"
dbExecute(conn, alter_game_log_command)
## [1] 0
# Use string concatenation to update this new column
update_game_log_command <- "
  UPDATE game_log
  SET game_id = date || h_name || number_of_game
  /* WHERE prevents this if it has already been done */
  WHERE game_id IS NULL;
"
dbExecute(conn, update_game_log_command)
## [1] 171907
# Make sure that your queries worked
check_query_1 <- "
  SELECT
      game_id,
      date,
      h_name,
      number_of_game
  FROM game_log
  LIMIT 5;
"
check <- dbGetQuery(conn, check_query_1)
head(check)
##        game_id     date h_name number_of_game
## 1 18710504FW10 18710504    FW1              0
## 2 18710505WS30 18710505    WS3              0
## 3 18710506RC10 18710506    RC1              0
## 4 18710508CH10 18710508    CH1              0
## 5 18710509TRO0 18710509    TRO              0

Looking for Normalization Opportunities

The following are opportunities for normalization of our data:

Creating Tables Without Foreign Keys

create_person_command <- "
  CREATE TABLE IF NOT EXISTS person (
      person_id TEXT PRIMARY KEY,
      first_name TEXT,
      last_name TEXT
);
"

dbExecute(conn, create_person_command)
## [1] 0
insert_to_person <- "
  INSERT OR IGNORE INTO person
  SELECT
      id,
      first,
      last
  FROM person_codes;
"

dbExecute(conn, insert_to_person)
## [1] 0
check_query_2 <- "SELECT * FROM person LIMIT 5;"

check <- dbGetQuery(conn, check_query_2)
head(check)
##   person_id first_name last_name
## 1  aardd001      David   Aardsma
## 2  aaroh101       Hank     Aaron
## 3  aarot101     Tommie     Aaron
## 4  aased001        Don      Aase
## 5  abada001       Andy      Abad
create_park_command <- "
  CREATE TABLE IF NOT EXISTS park (
      park_id TEXT PRIMARY KEY,
      name TEXT,
      nickname TEXT,
      city TEXT,
      state TEXT,
      notes TEXT
  );
"
dbExecute(conn, create_park_command)
## [1] 0
insert_to_park <- "
  INSERT OR IGNORE INTO park
  SELECT
      park_id,
      name,
      aka,
      city
  FROM park_codes;
"
dbExecute(conn, insert_to_park)
## [1] 0
check_query_3 <- "SELECT * FROM park LIMIT 5;"
check_3 <- dbGetQuery(conn, check_query_3)
create_league_command <- "
  CREATE TABLE IF NOT EXISTS league (
      league_id TEXT PRIMARY KEY,
      name TEXT
  );
"
dbExecute(conn, create_league_command)
## [1] 0
insert_to_league <- '
  INSERT OR IGNORE INTO league
  VALUES
      ("NL", "National League"),
      ("AL", "American League"),
      ("AA", "American Association"),
      ("FL", "Federal League"),
      ("PL", "Players League"),
      ("UA", "Union Association")
  ;
'
dbExecute(conn, insert_to_league)
## [1] 0
check_query_4 <- "SELECT * FROM league"
check <- dbGetQuery(conn, check_query_4)
head(check)
##   league_id                 name
## 1        NL      National League
## 2        AL      American League
## 3        AA American Association
## 4        FL       Federal League
## 5        PL       Players League
## 6        UA    Union Association
appearance_drop_precaution <- "DROP TABLE IF EXISTS appearance_type;"
dbExecute(conn, appearance_drop_precaution)
## [1] 0
appearance_type = read_csv('appearance_type.csv')
## Parsed with column specification:
## cols(
##   appearance_type_id = col_character(),
##   name = col_character(),
##   category = col_character()
## )
dbWriteTable(conn = conn, name = "appearance_type", 
             value = appearance_type,
             row.names = FALSE, header = TRUE)
check_query_5 <- "SELECT * FROM appearance_type;"
check <- dbGetQuery(conn, check_query_5)
head(check)
##   appearance_type_id     name category
## 1                 O1 Batter 1  offense
## 2                 O2 Batter 2  offense
## 3                 O3 Batter 3  offense
## 4                 O4 Batter 4  offense
## 5                 O5 Batter 5  offense
## 6                 O6 Batter 6  offense

Adding The Team and Game Tables

create_team_command <- "
  CREATE TABLE IF NOT EXISTS team (
      team_id TEXT PRIMARY KEY,
      league_id TEXT,
      city TEXT,
      nickname TEXT,
      franch_id TEXT,
      FOREIGN KEY (league_id) REFERENCES league(league_id)
  );
"

dbExecute(conn, create_team_command)
## [1] 0
insert_to_team <- "
  INSERT OR IGNORE INTO team
  SELECT
      team_id,
      league,
      city,
      nickname,
      franch_id
  FROM team_codes;
"

dbExecute(conn, insert_to_team)
## [1] 0
check_query_6 <- "SELECT * FROM team LIMIT 5;"

check <- dbGetQuery(conn, check_query_6)
head(check)
##   team_id league_id      city        nickname franch_id
## 1     ALT        UA   Altoona Mountain Cities       ALT
## 2     ARI        NL   Arizona    Diamondbacks       ARI
## 3     BFN        NL   Buffalo          Bisons       BFN
## 4     BFP        PL   Buffalo          Bisons       BFP
## 5     BL1           Baltimore        Canaries       BL1
create_game_command <- "
  CREATE TABLE IF NOT EXISTS game (
      game_id TEXT PRIMARY KEY,
      date TEXT,
      number_of_game INTEGER,
      park_id TEXT,
      length_outs INTEGER,
      day BOOLEAN,
      completion TEXT,
      forefeit TEXT,
      protest TEXT,
      attendance INTEGER,
      legnth_minutes INTEGER,
      additional_info TEXT,
      acquisition_info TEXT,
      FOREIGN KEY (park_id) REFERENCES park(park_id)
  );
"
dbExecute(conn, create_game_command)
## [1] 0
insert_to_game <- '
  INSERT OR IGNORE INTO game
  SELECT
      game_id,
      date,
      number_of_game,
      park_id,
      length_outs,
      CASE
          WHEN day_night = "D" THEN 1
          WHEN day_night = "N" THEN 0
          ELSE NULL
          END
          AS day,
      completion,
      forefeit,
      protest,
      attendance,
      length_minutes,
      additional_info,
      acquisition_info
  FROM game_log;
'
dbExecute(conn, insert_to_game)
## [1] 0
check_query_7 <- "SELECT * FROM game LIMIT 5;"
check <- dbGetQuery(conn, check_query_7)
head(check)
##        game_id     date number_of_game park_id length_outs day completion
## 1 18710504FW10 18710504              0   FOR01          54   1       <NA>
## 2 18710505WS30 18710505              0   WAS01          54   1       <NA>
## 3 18710506RC10 18710506              0   RCK01          54   1       <NA>
## 4 18710508CH10 18710508              0   CHI01          54   1       <NA>
## 5 18710509TRO0 18710509              0   TRO01          54   1       <NA>
##   forefeit protest attendance legnth_minutes additional_info acquisition_info
## 1     <NA>    <NA>        200            120            <NA>                Y
## 2     <NA>    <NA>       5000            145            HTBF                Y
## 3     <NA>    <NA>       1000            140            <NA>                Y
## 4     <NA>    <NA>       5000            150            <NA>                Y
## 5     <NA>    <NA>       3250            145            HTBF                Y

Adding the Team Appearance Table

create_team_appearance_command <- "
  CREATE TABLE IF NOT EXISTS team_appearance (
      team_id TEXT,
      game_id TEXT,
      home BOOLEAN,
      league_id TEXT,
      score INTEGER,
      line_score TEXT,
      at_bats INTEGER,
      hits INTEGER,
      doubles INTEGER,
      triples INTEGER,
      homeruns INTEGER,
      rbi INTEGER,
      sacrifice_hits INTEGER,
      sacrifice_flies INTEGER,
      hit_by_pitch INTEGER,
      walks INTEGER,
      intentional_walks INTEGER,
      strikeouts INTEGER,
      stolen_bases INTEGER,
      caught_stealing INTEGER,
      grounded_into_double INTEGER,
      first_catcher_interference INTEGER,
      left_on_base INTEGER,
      pitchers_used INTEGER,
      individual_earned_runs INTEGER,
      team_earned_runs INTEGER,
      wild_pitches INTEGER,
      balks INTEGER,
      putouts INTEGER,
      assists INTEGER,
      errors INTEGER,
      passed_balls INTEGER,
      double_plays INTEGER,
      triple_plays INTEGER,
      PRIMARY KEY (team_id, game_id),
      FOREIGN KEY (team_id) REFERENCES team(team_id),
      FOREIGN KEY (game_id) REFERENCES game(game_id),
      FOREIGN KEY (team_id) REFERENCES team(team_id)
  );
"
dbExecute(conn, create_team_appearance_command)
## [1] 0
insert_to_team_appearance <- "
  INSERT OR IGNORE INTO team_appearance
      SELECT
          h_name,
          game_id,
          1 AS home,
          h_league,
          h_score,
          h_line_score,
          h_at_bats,
          h_hits,
          h_doubles,
          h_triples,
          h_homeruns,
          h_rbi,
          h_sacrifice_hits,
          h_sacrifice_flies,
          h_hit_by_pitch,
          h_walks,
          h_intentional_walks,
          h_strikeouts,
          h_stolen_bases,
          h_caught_stealing,
          h_grounded_into_double,
          h_first_catcher_interference,
          h_left_on_base,
          h_pitchers_used,
          h_individual_earned_runs,
          h_team_earned_runs,
          h_wild_pitches,
          h_balks,
          h_putouts,
          h_assists,
          h_errors,
          h_passed_balls,
          h_double_plays,
          h_triple_plays
      FROM game_log
  
  UNION
  
      SELECT    
          v_name,
          game_id,
          0 AS home,
          v_league,
          v_score,
          v_line_score,
          v_at_bats,
          v_hits,
          v_doubles,
          v_triples,
          v_homeruns,
          v_rbi,
          v_sacrifice_hits,
          v_sacrifice_flies,
          v_hit_by_pitch,
          v_walks,
          v_intentional_walks,
          v_strikeouts,
          v_stolen_bases,
          v_caught_stealing,
          v_grounded_into_double,
          v_first_catcher_interference,
          v_left_on_base,
          v_pitchers_used,
          v_individual_earned_runs,
          v_team_earned_runs,
          v_wild_pitches,
          v_balks,
          v_putouts,
          v_assists,
          v_errors,
          v_passed_balls,
          v_double_plays,
          v_triple_plays
      from game_log;
"
dbExecute(conn, insert_to_team_appearance)
## [1] 0
check_query_8 <- "
  SELECT * FROM team_appearance
  WHERE game_id = (
                   SELECT MIN(game_id) from game
                  )
     OR game_id = (
                   SELECT MAX(game_id) from game
                  )
  ORDER By game_id, home;
"
check <- dbGetQuery(conn, check_query_8)
head(check)
##   team_id      game_id home league_id score line_score at_bats hits doubles
## 1     CL1 18710504FW10    0      <NA>     0  000000000      30    4       1
## 2     FW1 18710504FW10    1      <NA>     2  010010000      31    4       1
## 3     MIA 20161002WAS0    0        NL     7  000230020      38   14       1
## 4     WAS 20161002WAS0    1        NL    10  03023002x      30   10       2
##   triples homeruns rbi sacrifice_hits sacrifice_flies hit_by_pitch walks
## 1       0        0   0              0               0            0     1
## 2       0        0   2              0               0            0     1
## 3       1        2   7              1               0            0     3
## 4       0        1  10              1               1            1     8
##   intentional_walks strikeouts stolen_bases caught_stealing
## 1                NA          6            1              NA
## 2                NA          0            0              NA
## 3                 2         10            1               1
## 4                 0          3            2               0
##   grounded_into_double first_catcher_interference left_on_base pitchers_used
## 1                   -1                         NA            4             1
## 2                   -1                         NA            3             1
## 3                    1                          0            8             7
## 4                    1                          0            7             6
##   individual_earned_runs team_earned_runs wild_pitches balks putouts assists
## 1                      1                1            0     0      27       9
## 2                      0                0            0     0      27       3
## 3                     10               10            1     0      24      11
## 4                      7                7            1     0      27      11
##   errors passed_balls double_plays triple_plays
## 1      0            3            0            0
## 2      3            1            1            0
## 3      0            0            1            0
## 4      0            0            1            0

Adding the Person Appearance Table

drop_person_appearance_precaution <- "DROP TABLE IF EXISTS person_appearance"
dbExecute(conn, drop_person_appearance_precaution)
## [1] 0
create_person_appearance_command <- "
  CREATE TABLE person_appearance (
      appearance_id INTEGER PRIMARY KEY,
      person_id TEXT,
      team_id TEXT,
      game_id TEXT,
      appearance_type_id,
      FOREIGN KEY (person_id) REFERENCES person(person_id),
      FOREIGN KEY (team_id) REFERENCES team(team_id),
      FOREIGN KEY (game_id) REFERENCES game(game_id),
      FOREIGN KEY (appearance_type_id) REFERENCES appearance_type(appearance_type_id)
  );
"
dbExecute(conn, create_person_appearance_command)
## [1] 0
insert_to_person_appearance <- '
  INSERT OR IGNORE INTO person_appearance (
      game_id,
      team_id,
      person_id,
      appearance_type_id
  ) 
      SELECT
          game_id,
          NULL,
          hp_umpire_id,
          "UHP"
      FROM game_log
      WHERE hp_umpire_id IS NOT NULL    
  
  UNION
  
      SELECT
          game_id,
          NULL,
          [1b_umpire_id],
          "U1B"
      FROM game_log
      WHERE "1b_umpire_id" IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          NULL,
          [2b_umpire_id],
          "U2B"
      FROM game_log
      WHERE [2b_umpire_id] IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          NULL,
          [3b_umpire_id],
          "U3B"
      FROM game_log
      WHERE [3b_umpire_id] IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          NULL,
          lf_umpire_id,
          "ULF"
      FROM game_log
      WHERE lf_umpire_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          NULL,
          rf_umpire_id,
          "URF"
      FROM game_log
      WHERE rf_umpire_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          v_name,
          v_manager_id,
          "MM"
      FROM game_log
      WHERE v_manager_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          h_name,
          h_manager_id,
          "MM"
      FROM game_log
      WHERE h_manager_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          CASE
              WHEN h_score > v_score THEN h_name
              ELSE v_name
              END,
          winning_pitcher_id,
          "AWP"
      FROM game_log
      WHERE winning_pitcher_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          CASE
              WHEN h_score < v_score THEN h_name
              ELSE v_name
              END,
          losing_pitcher_id,
          "ALP"
      FROM game_log
      WHERE losing_pitcher_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          CASE
              WHEN h_score > v_score THEN h_name
              ELSE v_name
              END,
          saving_pitcher_id,
          "ASP"
      FROM game_log
      WHERE saving_pitcher_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          CASE
              WHEN h_score > v_score THEN h_name
              ELSE v_name
              END,
          winning_rbi_batter_id,
          "AWB"
      FROM game_log
      WHERE winning_rbi_batter_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          v_name,
          v_starting_pitcher_id,
          "PSP"
      FROM game_log
      WHERE v_starting_pitcher_id IS NOT NULL
  
  UNION
  
      SELECT
          game_id,
          h_name,
          h_starting_pitcher_id,
          "PSP"
      FROM game_log
      WHERE h_starting_pitcher_id IS NOT NULL;
'
dbExecute(conn, insert_to_person_appearance)
## [1] 1646118
for (letter in c("h", "v")) {
  for (num in 1:9) {
    template <- '
      INSERT INTO person_appearance (
          game_id,
          team_id,
          person_id,
          appearance_type_id
      ) 
          SELECT
              game_id,
              %s_name,
              %s_player_%f_id,
              "O%f"
          FROM game_log
          WHERE %s_player_%f_id IS NOT NULL
      
      UNION
      
          SELECT
              game_id,
              %s_name,
              %s_player_%f_id,
              "D" || CAST(%s_player_%f_def_pos AS INT)
          FROM game_log
          WHERE %s_player_%f_id IS NOT NULL;
    '
    # replace all of the %s and %f with the correct letter number
    template <- gsub("%s", letter, template, fixed = TRUE)
    template <- gsub("%f", num, template, fixed = TRUE)
    
    dbExecute(conn, template)
  }
}

This particular solution incorporates a bit of regular expression and some nested for loops. If you need to review for-loops again, refer to our older mission on control structures. Regular expression is a technique where we look for specific patterns in a character vector and replace it with another pattern. In this case, we need to replace all the instances of “%s” and “%f” with a new letter and number, respectively. In particular, the gsub() function replaces all instances of “%s” and “%f” respectively. With each run of the nested loop, we get a properly formatted query that fulfills our needs. Using loops is one potential solution, but it’s also possible to vectorize this work and recreate what we need.

Removing the Original Tables

# Check the current status of the db file
dbListTables(conn)
##  [1] "appearance_type"   "game"              "game_log"         
##  [4] "games_log"         "league"            "park"             
##  [7] "park_code"         "park_codes"        "person"           
## [10] "person_appearance" "person_code"       "person_codes"     
## [13] "team"              "team_appearance"   "team_code"        
## [16] "team_codes"
# Iterate through each of the tables
tables <- c("game_log", "park_codes",
            "team_codes", "person_codes")
for (t in tables) {
  drop_command = sprintf("DROP TABLE %s", t)
  dbExecute(conn, drop_command)
}
# Make sure that everything is gone
dbListTables(conn)
##  [1] "appearance_type"   "game"              "games_log"        
##  [4] "league"            "park"              "park_code"        
##  [7] "person"            "person_appearance" "person_code"      
## [10] "team"              "team_appearance"   "team_code"
dbDisconnect(conn)