Cursor –[游标]：Step1——Example table 1×2CREATE TABLE product_types ( product_type_id INTEGER CONSTRAINT product_types_pk PRIMARY KEY, name VARCHAR2(10) NOT NULL);/CREATE TABLE products ( product_id INTEGER CONSTRAINT products_pk PRIMARY KEY, product_type_id INTEGER CONSTRAINT products_...

INSTR(x, find_string [, start] [, occurrence]) Searches for find_string in x and returns the position at which find_string occurs. You can supply an optional start position to begin the search. Also, you can supply an optional occurrence that indicates which occurrence of find_string should be...