| ! expr | Logical not. | 
    
      | expr1 < expr2 | Returns true if `expr1` is less than `expr2`. | 
    
      | expr1 <= expr2 | Returns true if `expr1` is less than or equal to `expr2`. | 
    
      | expr1 <=> expr2 | Returns same result as the EQUAL(=) operator for non-null operands,
      but returns true if both are null, false if one of the them is null. | 
    
      | expr1 = expr2 | Returns true if `expr1` equals `expr2`, or false otherwise. | 
    
      | expr1 == expr2 | Returns true if `expr1` equals `expr2`, or false otherwise. | 
    
      | expr1 > expr2 | Returns true if `expr1` is greater than `expr2`. | 
    
      | expr1 >= expr2 | Returns true if `expr1` is greater than or equal to `expr2`. | 
    
      | expr1 and expr2 | Logical AND. | 
    
      | equal_null(expr1, expr2) | Returns same result as the EQUAL(=) operator for non-null operands,
      but returns true if both are null, false if one of the them is null. | 
    
      | str ilike pattern[ ESCAPE escape] | Returns true if str matches `pattern` with `escape` case-insensitively, null if any arguments are null, false otherwise. | 
    
      | expr1 in(expr2, expr3, ...) | Returns true if `expr` equals to any valN. | 
    
      | isnan(expr) | Returns true if `expr` is NaN, or false otherwise. | 
    
      | isnotnull(expr) | Returns true if `expr` is not null, or false otherwise. | 
    
      | isnull(expr) | Returns true if `expr` is null, or false otherwise. | 
    
      | str like pattern[ ESCAPE escape] | Returns true if str matches `pattern` with `escape`, null if any arguments are null, false otherwise. | 
    
      | not expr | Logical not. | 
    
      | expr1 or expr2 | Logical OR. | 
    
      | regexp(str, regexp) | Returns true if `str` matches `regexp`, or false otherwise. | 
    
      | regexp_like(str, regexp) | Returns true if `str` matches `regexp`, or false otherwise. | 
    
      | rlike(str, regexp) | Returns true if `str` matches `regexp`, or false otherwise. |