spec_sql_unquote_identifier

Value

dbUnquoteIdentifier() returns a list of objects of the same length as the input. For an empty vector, this function returns a length-0 object. The names of the input argument are preserved in the output. If x is a value returned by dbUnquoteIdentifier(), calling dbUnquoteIdentifier(..., dbQuoteIdentifier(..., x))

returns list(x). If x is an object of class Id, calling dbUnquoteIdentifier(..., x) returns list(x). (For backends it may be most convenient to return Id objects to achieve this behavior, but this is not required.)

Plain character vectors can also be passed to dbUnquoteIdentifier().

Failure modes

An error is raised if a character vectors with a missing value is passed as the x argument.

Specification

For any character vector of length one, quoting (with dbQuoteIdentifier()) then unquoting then quoting the first element is identical to just quoting. This is also true for strings that contain special characters such as a space, a dot, a comma, or quotes used to mark strings or identifiers, if the database supports this.

Unquoting simple strings (consisting of only letters) wrapped with SQL() and then quoting via dbQuoteIdentifier() gives the same result as just quoting the string. Similarly, unquoting expressions of the form SQL("schema.table") and then quoting gives the same result as quoting the identifier constructed by Id("schema", "table").