2011-10-28 LIKE条件中的通配符

http://www.itpub.net/thread-1499223-10-1.html

93楼

我创建了这张表并填入数据：

CREATE TABLE plch_new_parts(   partnum    NUMBER, partname   VARCHAR2 (50))/ BEGIN   INSERT INTO plch_new_parts (partnum, partname)        VALUES (1, 'MY PART NUMBER 1');   INSERT INTO plch_new_parts (partnum, partname)        VALUES (2, 'MY_PART_NUMBER_2');   INSERT INTO plch_new_parts (partnum, partname)        VALUES (3, 'MY_PART NUMBER_3');   COMMIT;END;/

当我执行下列这段代码，屏幕上会显示什么？

DECLARE   l_counts   DBMS_SQL.number_table;BEGIN   l_counts (1) := 0;   l_counts (2) := 0;   l_counts (3) := 0;   l_counts (4) := 0;   FOR rec IN (  SELECT partname                   FROM plch_new_parts               ORDER BY partnum)   LOOP      IF rec.partname LIKE 'MY PART NUMBER %'      THEN         l_counts (1) := l_counts (1) + 1;      END IF;      IF rec.partname LIKE 'MY_PART_NUMBER_%'      THEN         l_counts (2) := l_counts (2) + 1;      END IF;      IF rec.partname LIKE 'MY_PART NUMBER_%'      THEN         l_counts (3) := l_counts (3) + 1;      END IF;      IF rec.partname LIKE 'MY?PART?NUMBER?*'      THEN         l_counts (4) := l_counts (4) + 1;      END IF;   END LOOP;   FOR indx IN 1 .. l_counts.COUNT   LOOP      DBMS_OUTPUT.put_line (l_counts (indx));   END LOOP;END;/

(A)

1110

(B)

1320

(C)

0 0 0 3

(D)

3333

(E)

1323

运行结果如下

SQL> DECLARE  2     l_counts   DBMS_SQL.number_table;  3    4  BEGIN  5     l_counts (1) := 0;  6     l_counts (2) := 0;  7     l_counts (3) := 0;  8     l_counts (4) := 0;  9   10     FOR rec IN (  SELECT partname 11                     FROM plch_new_parts 12                 ORDER BY partnum) 13     LOOP 14        IF rec.partname LIKE 'MY PART NUMBER %' 15        THEN 16           l_counts (1) := l_counts (1) + 1; 17        END IF; 18   19        IF rec.partname LIKE 'MY_PART_NUMBER_%' 20        THEN 21           l_counts (2) := l_counts (2) + 1; 22        END IF; 23   24        IF rec.partname LIKE 'MY_PART NUMBER_%' 25        THEN 26           l_counts (3) := l_counts (3) + 1; 27        END IF; 28   29        IF rec.partname LIKE 'MY?PART?NUMBER?*' 30        THEN 31           l_counts (4) := l_counts (4) + 1; 32        END IF; 33     END LOOP; 34   35     FOR indx IN 1 .. l_counts.COUNT 36     LOOP 37        DBMS_OUTPUT.put_line (l_counts (indx)); 38     END LOOP; 39  END; 40  /132PL/SQL procedure successfully completedSQL>

答案B

答案说明96楼

2011-10-28答案B._匹配单个字符，%匹配任意个字符，*和?是忽悠人的。