Ruby Type SQL Type NilClass (nil) NULL TrueClass, FalseClass (true, false) CHAR(1), BOOL String VARCHAR, CHAR, TEXT Integer (Fixnum or Bignum) INT, BIGINT Float FLOAT, DOUBLE, REAL DBI::Binary BLOB, CLOB, LONG, LONG RAW DBI::Time (or String) TIME DBI::Date (or String) DATE DBI::Timestamp (or String) TIMESTAMP