Error: Error in dbSendQuery(conn, statement, ...) : CHAR() can only be applied to a 'CHARSXP', not a 'NULL' Called from: dbSendQuery(conn, statement, ...)

[geneticist-lab]

Hello , Please review the following error message:
Error in dbSendQuery(conn, statement, ...) :
CHAR() can only be applied to a 'CHARSXP', not a 'NULL'
Called from: dbSendQuery(conn, statement, ...)