" ALL_TAB_COLUMNS 是一个systable，具有所有表列的数据类型，等等.

"ALL_TAB_COLUMNS" is a systable, have all table columns data type etc.

" USER_TAB_COLUMNS "是一个systable，具有所有表列数据类型，等等(所有者是当前用户). (感谢Rene)

"USER_TAB_COLUMNS" is a systable, have all table columns data type etc (which owner is current user). (Thanks Rene)

示例:

 SET SERVEROUTPUT ON SIZE 100000 -- maybe you have a lot of table and columns

    DECLARE
      matches INTEGER;
    BEGIN
      FOR columns IN (SELECT table_name, column_name FROM user_tab_columns where data_type = 'VARCHAR2') LOOP

        EXECUTE IMMEDIATE
          'SELECT COUNT(*) FROM '||t.table_name||' WHERE instr('||t.column_name||' , :1) > 0'
          INTO matches
          USING 'What you search';

        IF matches > 0 THEN
          dbms_output.put_line( t.table_name ||' '||t.column_name||' '||matches );
        END IF;

      END LOOP;

    END;
    /

此查询将输出table_name''column_name''并进行计数，如果您具有标准列和表名，则可以将查询更改为IF列> 0，然后在循环中编写查询UNION并返回游标，或返回表，

this query will output table_name '' column_name'' and count, if you have standart column and table names, you can change query as IF columns > 0 then write a query UNION in loop and return the cursor, or return a table,