These are the operators that can be used in where clauses; see Where Clauses for more information:

op_between(): for the "between" operator
op_in(): for the "in" operator
op_in_select(): for the "in" operator with a query argument
op_like(): for the "like" operator
op_substr(): for the "substr" operator
op_ge(): for the ">=" operator when comparing column values to immediate values
op_gt(): for the ">" operator when comparing column values to immediate values
op_le(): for the "<=" operator when comparing column values to immediate values
op_lt(): for the "<" operator when comparing column values to immediate values
op_ne(): for the "!=" or "<>" operator when comparing column values to immediate values
op_eq(): for the "=" operator when comparing column values to immediate values
op_not(): for negating other operators
op_cge(): for the ">=" operator when comparing the values of two columns
op_cgt(): for the ">" operator when comparing the values of two columns
op_cle(): for the "<=" operator when comparing the values of two columns
op_clt(): for the "<" operator when comparingthe values of two columns
op_cne(): for the "!=" or "<>" operator when comparing the values of two columns
op_ceq(): for the "=" operator when comparing the values of two columns
wop_or(): for combining SQL expressions with "or"