DBI: make.db.names – R documentation

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DBI

make.db.names

Make R identifiers into legal SQL identifiers

Description

These methods are DEPRECATED. Please use dbQuoteIdentifier() (or possibly dbQuoteString()) instead.

Usage

make.db.names(
  dbObj,
  snames,
  keywords = .SQL92Keywords,
  unique = TRUE,
  allow.keywords = TRUE,
  ...
)

make.db.names.default(
  snames,
  keywords = .SQL92Keywords,
  unique = TRUE,
  allow.keywords = TRUE
)

isSQLKeyword(
  dbObj,
  name,
  keywords = .SQL92Keywords,
  case = c("lower", "upper", "any")[3],
  ...
)

isSQLKeyword.default(
  name,
  keywords = .SQL92Keywords,
  case = c("lower", "upper", "any")[3]
)

Arguments

`dbObj`	any DBI object (e.g., `DBIDriver`).
`snames`	a character vector of R identifiers (symbols) from which we need to make SQL identifiers.
`keywords`	a character vector with SQL keywords, by default it's `.SQL92Keywords` defined by the DBI.
`unique`	logical describing whether the resulting set of SQL names should be unique. Its default is `TRUE`. Following the SQL 92 standard, uniqueness of SQL identifiers is determined regardless of whether letters are upper or lower case.
`allow.keywords`	logical describing whether SQL keywords should be allowed in the resulting set of SQL names. Its default is `TRUE`
`...`	any other argument are passed to the driver implementation.
`name`	a character vector with database identifier candidates we need to determine whether they are legal SQL identifiers or not.
`case`	a character string specifying whether to make the comparison as lower case, upper case, or any of the two. it defaults to `any`.

Details

The algorithm in make.db.names first invokes make.names and then replaces each occurrence of a dot . by an underscore _. If allow.keywords is FALSE and identifiers collide with SQL keywords, a small integer is appended to the identifier in the form of "_n".

The set of SQL keywords is stored in the character vector .SQL92Keywords and reflects the SQL ANSI/ISO standard as documented in "X/Open SQL and RDA", 1994, ISBN 1-872630-68-8. Users can easily override or update this vector.

Value

make.db.names returns a character vector of legal SQL identifiers corresponding to its snames argument.

SQLKeywords returns a character vector of all known keywords for the database-engine associated with dbObj.

isSQLKeyword returns a logical vector parallel to name.

Bugs

The current mapping is not guaranteed to be fully reversible: some SQL identifiers that get mapped into R identifiers with make.names and then back to SQL with make.db.names() will not be equal to the original SQL identifiers (e.g., compound SQL identifiers of the form username.tablename will loose the dot “.”).

References

DBI

R Database Interface

v1.1.1

LGPL (>= 2.1)

Authors

R Special Interest Group on Databases (R-SIG-DB) [aut], Hadley Wickham [aut], Kirill Müller [aut, cre] (<https://orcid.org/0000-0002-1416-3412>), R Consortium [fnd]

Initial release

2021-01-04