eatDB (educational assessment tools: Data Bases) enables the use of relational data bases via a pure R interface. It uses SQLlite3 as a back end and makes use of the packages DBI and RSQLite. When a relational data base with multiple data tables is created via createDB, the user specifies the order in which the data tables are merged when data is later extracted from the data base. The fkList specifies which data table references to which other data table via which ID variable.
eatDB makes use of consistency checks of SQLite3 via using the definition of primary and foreign keys. Additionally, meta data (e.g. variable and value labels) can be stored in a separate data table as part of the relational data base.
### Setup data base
pkList <- list(df1 = "ID2", df2 = "v2")
fkList <- list(df1 = list(References = NULL, Keys = NULL),
df2 = list(References = "df1", Keys = "ID2"))
createDB(dfList = dfList, pkList = pkList, fkList = fkList, filePath = "insert/path/example.db")
### get information from data base
names_of_variables <- dbNames(filePath = "insert/path/example.db")
key_structure <- dbKeys(filePath = "insert/path/example.db")
### pull data from data base
# single data table
single_data_table <- dbSingleDF(df_name = "df1", filePath = "insert/path/example.db")
# variable selection from multiple tables
dbSingleDF(vSelect = c("var1", "var2"), filePath = "insert/path/example.db")