Package 'validatedb'

Title: Validate Data in a Database using 'validate'
Description: Check whether records in a database table are valid using validation rules in R syntax specified with R package 'validate'. R validation checks are automatically translated to SQL using 'dbplyr'.
Authors: Edwin de Jonge [aut, cre]
Maintainer: Edwin de Jonge <[email protected]>
License: GPL-3
Version: 0.3.2.9000
Built: 2024-11-01 11:24:03 UTC
Source: https://github.com/data-cleaning/validatedb

Help Index


Count the number of invalid rules or records.

Description

See the number of valid and invalid checks either by rule or by record.

Usage

## S3 method for class 'tbl_validation'
aggregate(x, by = c("rule", "record", "key"), ...)

Arguments

x

tbl_validation() object

by

either by "rule" or by "record"

...

not used

Details

The result of a confront() on a db tbl results in a lazy squery. That is it builds a query without executing it. To store the result in the database use compute() or values().

Value

A dbplyr::tbl_dbi() object that represents the aggregation query (to be executed) on the database.

Examples

income <- data.frame(id = 1:2, age=c(12,35), salary = c(1000,NA))
con <- dbplyr::src_memdb()
tbl_income <- dplyr::copy_to(con, income, overwrite=TRUE)
print(tbl_income)

# Let's define a rule set and confront the table with it:
rules <- validator( is_adult   = age >= 18
                    , has_income = salary > 0
)

# and confront!
# in general with a db table it is handy to use a key
cf <- confront(tbl_income, rules, key="id")
aggregate(cf, by = "rule")
aggregate(cf, by = "record")

# to tweak performance of the db query the following options are available
# 1) store validation result in db
cf <- confront(tbl_income, rules, key="id", compute = TRUE)
# or identical
cf <- confront(tbl_income, rules, key="id")
cf <- compute(cf)

# 2) Store the validation sparsely
cf_sparse <- confront(tbl_income, rules, key="id", sparse=TRUE )

show_query(cf_sparse)
values(cf_sparse, type="tbl")

Retrieve validation results as a data.frame

Description

Retrieve validation results as a data.frame

Usage

## S3 method for class 'tbl_validation'
as.data.frame(x, row.names = NULL, optional = FALSE, ...)

Arguments

x

tbl_validation(), result of a confront() of tbl with a rule set.

row.names

ignored

optional

ignored

...

ignored

Value

data.frame, result of the query on the database.

Examples

# create a table in a database
income <- data.frame(id = letters[1:2], age=c(12,35), salary = c(1000,NA))
con <- dbplyr::src_memdb()
tbl_income <- dplyr::copy_to(con, income, overwrite=TRUE)

# Let's define a rule set and confront the table with it:
rules <- validator( is_adult   = age >= 18
                  , has_income = salary > 0
                  , mean_age   = mean(age,na.rm=TRUE) > 20
                  )
# and confront!
cf <- confront(tbl_income, rules, key = "id")
as.data.frame(cf)

# and now with a sparse result:
cf <- confront(tbl_income, rules, key = "id", sparse=TRUE)
as.data.frame(cf)

Check validation rules on the database

Description

Checks whether validation rules are working on the database, and gives hints on non working rules.

Usage

check_rules(tbl, x, key = NULL)

Arguments

tbl

dbplyr::tbl_dbi() table in a database, retrieved with tbl()

x

validate::validator() object with validation rules.

key

character with key column name, must be specified

Details

validatedb translates validation rules using dbplyr on a database. Every database engine is different, so it may happen that some validation rules will not work. This function helps in finding out why rules are not working.

In some (easy to fix) cases, this may be due to:

  • using variables that are not present in the table

  • using a different value type than the column in the database, e.g.using an integer value, while the database column is of type "varchar".

  • To debug your rules, a useful thing to do is first to test the rules on a small sub set of the table

  • e.g.

tbl |> 
  head() |>          # debugging on db
  as.data.frame() |> # debugging "rules", do they work on a data.frame
  confront(rules, key = "id") |> 
  summary()

But it can also be that some R functions are not available on the database, in which case you have to reformulate the rule.

Value

data.frame with name, rule, working, sql for each rule.

Examples

person <- dbplyr::memdb_frame(id = letters[1:2], age = c(12, 20))
rules <- validator(age >= 18)

check_rules(person, rules, key = "id")

# use the result of check_rules to find out more on the translation
res <- check_rules(person, rules, key = "id")

print(res[-4])
writeLines(res$sql)

Store the validation result in the db

Description

Stores the validation result in the db using the dplyr::compute() of the db back-end. This method changes the tbl_validation object! Note that for most back-ends the default setting is a temporary table with a random name.

Usage

## S3 method for class 'tbl_validation'
compute(x, name, ...)

Arguments

x

tbl_validation(), result of a confront() of tbl with a rule set.

name

optional, when omitted, a random name is used.

...

passed through to compute on x$query

Value

A dbplyr::tbl_dbi() object that refers to the computed (temporary) table in the database. See dplyr::compute().

See Also

Other tbl_validation: tbl_validation-class


Create a sparse confrontation query

Description

Create a sparse confrontation query. Only errors and missing are stored. This stores all results of a tbl validation in a table with length(rules) columns and nrow(tbl) rows. Note that the result of this function is a (lazy) query object that still needs to be executed in the database, e.g. with dplyr::collect(), dplyr::collapse() or dplyr::compute().

Usage

confront_tbl_sparse(tbl, x, key, union_all = TRUE, check_rules = TRUE)

Arguments

tbl

dbplyr::tbl_dbi() table in a database, retrieved with tbl()

x

validate::validator() object with validation rules.

key

character with key column name, must be specified

union_all

if FALSE each rule is a separate query.

check_rules

if TRUE it is checked which rules 'work' on the db.

Details

The return value of the function is a list with:

  • ⁠$query⁠: A dbplyr::tbl_dbi() object that refers to the confrontation query.

  • ⁠$errors⁠: The validation rules that are not working on the database

  • ⁠$working⁠: A logical with which expression are working on the database.

  • ⁠$exprs⁠: All validation expressions.

Value

A object with the necessary information: see details

See Also

Other validation: tbl_validation-class, values,tbl_validation-method

Examples

# create a table in a database
income <- data.frame(id = letters[1:2], age=c(12,35), salary = c(1000,NA))
con <- dbplyr::src_memdb()
tbl_income <- dplyr::copy_to(con, income, overwrite=TRUE)
print(tbl_income)

# Let's define a rule set and confront the table with it:
rules <- validator( is_adult   = age >= 18
                  , has_income = salary > 0
                  , mean_age   = mean(age,na.rm=TRUE) > 20
                  )

# and confront! (we have to use a key, because a db...)
cf <- confront(tbl_income, rules, key = "id")
print(cf)
summary(cf)

# Values (i.e. validations on the table) can be retrieved like in `validate` 
# with`type="matrix"` (simplify = TRUE)
values(cf, type = "matrix")

# But often this seems more handy:
values(cf, type = "tbl")

# We can see the sql code by using `show_query`:
show_query(cf)

# identical
show_query(values(cf, type = "tbl"))

# sparse results in db (that the default)
values(cf, type="tbl", sparse=TRUE)

# or if you like data.frames
values(cf, type="data.frame", sparse=TRUE)

Validate data in database tbl with validator rules.

Description

Confront dbplyr::tbl_dbi() objects with validate::validator() rules, making it possible to execute validator() rules on database tables. Validation results can be stored in the db or retrieved into R.

Usage

confront.tbl_sql(tbl, x, ref, key, sparse = FALSE, compute = FALSE, ...)

## S4 method for signature 'ANY,validator,ANY'
confront(dat, x, ref, key = NULL, sparse = FALSE, ...)

Arguments

tbl

dbplyr::tbl_dbi() table in a database, retrieved with tbl()

x

validate::validator() object with validation rules.

ref

reference object (not working)

key

character with key column name, must be specified

sparse

logical should only fails be stored in the db?

compute

logical if TRUE the check stores a temporary table in the database.

...

passed through to compute(), if compute is TRUE

dat

an object of class 'tbl_sql“.

Details

validatedb builds upon dplyr and dbplyr, so it works on all databases that have a dbplyr compatible database driver (DBI / odbc). validatedb translates validator rules into dplyr commands resulting in a lazy query object. The result of a validation can be stored in the database using compute or retrieved into R with values.

Value

a tbl_validation() object, containing the confrontation query and processing information.

See Also

Other validation: tbl_validation-class, values,tbl_validation-method

Examples

# create a table in a database
income <- data.frame(id = letters[1:2], age=c(12,35), salary = c(1000,NA))
con <- dbplyr::src_memdb()
tbl_income <- dplyr::copy_to(con, income, overwrite=TRUE)
print(tbl_income)

# Let's define a rule set and confront the table with it:
rules <- validator( is_adult   = age >= 18
                  , has_income = salary > 0
                  , mean_age   = mean(age,na.rm=TRUE) > 20
                  )

# and confront! (we have to use a key, because a db...)
cf <- confront(tbl_income, rules, key = "id")
print(cf)
summary(cf)

# Values (i.e. validations on the table) can be retrieved like in `validate` 
# with`type="matrix"` (simplify = TRUE)
values(cf, type = "matrix")

# But often this seems more handy:
values(cf, type = "tbl")

# We can see the sql code by using `show_query`:
show_query(cf)

# identical
show_query(values(cf, type = "tbl"))

# sparse results in db (that the default)
values(cf, type="tbl", sparse=TRUE)

# or if you like data.frames
values(cf, type="data.frame", sparse=TRUE)

dump sql statements

Description

Write sql statements of a tbl confrontation.

Usage

dump_sql(x, sql_file = stdout(), sparse = x$sparse, ...)

Arguments

x

tbl_validation object

sql_file

filename/connection where the sql code should be written to.

sparse

not used

...

not used


tests for each rule if it can be executed on the database

Description

tests for each rule if it can be executed on the database

Usage

rule_works_on_tbl(tbl, x, key = NULL, show_errors = FALSE)

Arguments

tbl

a tbl object with columns used in x

x

a validate::validator() object

key

character names of columns that identify a record

show_errors

if TRUE errors on the database are printed.

Value

logical encoding which validation rules "work" on the database.


Show generated sql code

Description

Shows the generated sql code for the validation of the tbl.

Usage

## S3 method for class 'tbl_validation'
show_query(x, ..., sparse = x$sparse)

Arguments

x

tbl_validation() object, result of a confront.tbl_sql().

...

passed through.

sparse

logical if FALSE the query will be a dense query.

Value

Same result as dplyr::show_query, i.e. the SQL text of the query.


Validation object for tbl object

Description

Validation information for a database tbl, result of a confront.tbl_sql().

Details

The tbl_validation object contains all information needed for the confrontation of validation rules with the data in the database table. It contains:

  • ⁠$query⁠: a dbplyr::tbl_dbi object with the query to be executed on the database

  • ⁠$tbl⁠: the dbplyr::tbl_dbi pointing to the table in the database

  • ⁠$key⁠: Whether there is a key column, and if so, what it is.

  • ⁠$record_based⁠: logical with which rules are record based.

  • ⁠$exprs⁠: list of validation rule expressions

  • ⁠$working⁠: logical, which of the rules work on the database. (whether the database supports this expression)

  • ⁠$errors⁠: list of validation rules that did not execute on the database.

  • ⁠$sparse⁠: If TRUE the query default presented as a sparse validation object.

  • ⁠$subqueries⁠: list of sparse queries for each of the rules.

Value

tbl_validation object. See details.

See Also

Other validation: confront.tbl_sql(), values,tbl_validation-method

Other tbl_validation: compute.tbl_validation()


Retrieve the result of a validation/confrontation

Description

Retrieve the result of a validation/confrontation.

Usage

## S4 method for signature 'tbl_validation'
values(
  x,
  simplify = type == "matrix",
  drop = FALSE,
  type = c("tbl", "matrix", "list", "data.frame"),
  sparse = x$sparse,
  ...
)

Arguments

x

tbl_validation(), result of a confront() of tbl with a rule set.

simplify

only use when type = "list" see validate::values

drop

not used at the moment

type

whether to return a list/matrix or to return a query on the database.

sparse

whether to show the results as a sparse query (only fails and NA) or all results for each record.

...

not used

Details

Since the validation is done on a database, there are multiple options for storing the result of the validation. The results show per record whether they are valid according to the validation rules supplied.

  • Use compute (see confront.tbl_sql()) to store the result in the database

  • Use sparse to only calculate "fails" and "missings"

Default type "tbl" is that everything is "lazy", so the query and/or storage has to be done explicitly by the user. The other types execute the query and retrieve the result into R. When this creates memory problems, the tbl option is to be preferred.

Results for type:

Value

depending on type the result is different, see details

See Also

Other validation: confront.tbl_sql(), tbl_validation-class

Examples

# create a table in a database
income <- data.frame(id = letters[1:2], age=c(12,35), salary = c(1000,NA))
con <- dbplyr::src_memdb()
tbl_income <- dplyr::copy_to(con, income, overwrite=TRUE)
print(tbl_income)

# Let's define a rule set and confront the table with it:
rules <- validator( is_adult   = age >= 18
                  , has_income = salary > 0
                  , mean_age   = mean(age,na.rm=TRUE) > 20
                  )

# and confront! (we have to use a key, because a db...)
cf <- confront(tbl_income, rules, key = "id")
print(cf)
summary(cf)

# Values (i.e. validations on the table) can be retrieved like in `validate` 
# with`type="matrix"` (simplify = TRUE)
values(cf, type = "matrix")

# But often this seems more handy:
values(cf, type = "tbl")

# We can see the sql code by using `show_query`:
show_query(cf)

# identical
show_query(values(cf, type = "tbl"))

# sparse results in db (that the default)
values(cf, type="tbl", sparse=TRUE)

# or if you like data.frames
values(cf, type="data.frame", sparse=TRUE)