Validate if a data frame column confirms to primary key/ID constraints

ValidatePrimKey checks if a column in a data frame confirms to the primary key/ID constraints of absence of duplicates and NULL values. Aberrant records if encountered are returned in the output list.

ValidatePrimKey(x, prim.key)

Arguments

x

A data frame.

prim.key

A character vector indicating the name of the data frame column to be validated for primary key/ID constraints (see Details).

Value

A list with containing the following components:

message1	Indicates whether duplicated values were encountered in prim.key field(column) of data frame x or not.
Duplicates	A data frame of the records with duplicated prim.key values if they were encountered.
message2	Indicates whether NULL values were encountered in prim.key field(column) of data frame x or not.
NullRecords	A data frame of the records with NULL prim.key values if they were encountered.

Details

The function checks whether a field(column) in a data frame of PGR passport database confirms to the primary key/ID constraints of absence of duplicates and NULL values. If records with nonconforming values in the column are encountered, they are returned in the output list for rectification.

If multiple fields(columns) are given as a character vector in prim.key field, only the first element will be considered as the primary key/ID field(column).

Cleaning of the data in the input field(column) using the DataClean function with appropriate arguments is suggested before running this function.

It is recommended to run this function and rectify aberrant records in a PGR passport database before creating a KWIC index using the KWIC function.

See also

DataClean, KWIC

Examples

GN <- GN1000
ValidatePrimKey(x=GN, prim.key="NationalID")
#> OK: No duplicated records found in prim.key field
#> OK: No NULL records found in prim.key field
#> $message1
#> [1] "OK: No duplicated records found in prim.key field"
#> 
#> $Duplicates
#> NULL
#> 
#> $message2
#> [1] "OK: No NULL records found in prim.key field"
#> 
#> $NullRecords
#> NULL
#> 
if (FALSE) {
# Show error in case of duplicates and NULL values 
# in the primary key/ID field "NationalID"
GN[1001:1005,] <- GN[1:5,]
GN[1001,3] <- ""
ValidatePrimKey(x=GN, prim.key="NationalID")}