从别的数据库里拿到的获取拼音简码的函数，觉得挺有意思的，具体的思路就是，通过oracle的NLSSORT函数对汉字按照拼音排序，然后根据汉字的区间返回对应的首字母。具体实现效果和代码如下。
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/* 获取拼音简码函数 */
CREATE OR REPLACE FUNCTION GET_PYJM (P_NAME IN VARCHAR2)
RETURN VARCHAR2
AS
V_COMPARE VARCHAR2 (100);
V_RETURN VARCHAR2 (4000);
BEGIN
DECLARE
FUNCTION F_NLSSORT (P_WORD IN VARCHAR2)
RETURN VARCHAR2
AS
BEGIN
RETURN NLSSORT (P_WORD, 'NLS_SORT=SCHINESE_PINYIN_M');
END;
BEGIN
FOR I IN 1 .. LENGTH (P_NAME)
LOOP
V_COMPARE := F_NLSSORT (SUBSTR (P_NAME, I, 1));
IF V_COMPARE >= F_NLSSORT ('吖')
AND V_COMPARE <= F_NLSSORT ('驁')
THEN
V_RETURN := V_RETURN || 'A';
ELSIF V_COMPARE >= F_NLSSORT ('八')
AND V_COMPARE <= F_NLSSORT ('簿')
THEN
V_RETURN := V_RETURN || 'B';
ELSIF V_COMPARE >= F_NLSSORT ('嚓')
AND V_COMPARE <= F_NLSSORT ('錯')
THEN
V_RETURN := V_RETURN || 'C';
ELSIF V_COMPARE >= F_NLSSORT ('咑')
AND V_COMPARE <= F_NLSSORT ('鵽')
THEN
V_RETURN := V_RETURN || 'D';
ELSIF V_COMPARE >= F_NLSSORT ('妸')
AND V_COMPARE <= F_NLSSORT ('樲')
THEN
V_RETURN := V_RETURN || 'E';
ELSIF V_COMPARE >= F_NLSSORT ('发')
AND V_COMPARE <= F_NLSSORT ('猤')
THEN
V_RETURN := V_RETURN || 'F';
ELSIF V_COMPARE >= F_NLSSORT ('旮')
AND V_COMPARE <= F_NLSSORT ('腂')
THEN
V_RETURN := V_RETURN || 'G';
ELSIF V_COMPARE >= F_NLSSORT ('妎')
AND V_COMPARE <= F_NLSSORT ('夻')
THEN
V_RETURN := V_RETURN || 'H';
ELSIF V_COMPARE >= F_NLSSORT ('丌')
AND V_COMPARE <= F_NLSSORT ('攈')
THEN
V_RETURN := V_RETURN || 'J';
ELSIF V_COMPARE >= F_NLSSORT ('咔')
AND V_COMPARE <= F_NLSSORT ('穒')
THEN
V_RETURN := V_RETURN || 'K';
ELSIF V_COMPARE >= F_NLSSORT ('垃')
AND V_COMPARE <= F_NLSSORT ('擽')
THEN
V_RETURN := V_RETURN || 'L';
ELSIF V_COMPARE >= F_NLSSORT ('嘸')
AND V_COMPARE <= F_NLSSORT ('椧')
THEN
V_RETURN := V_RETURN || 'M';
ELSIF V_COMPARE >= F_NLSSORT ('拏')
AND V_COMPARE <= F_NLSSORT ('瘧')
THEN
V_RETURN := V_RETURN || 'N';
ELSIF V_COMPARE >= F_NLSSORT ('筽')
AND V_COMPARE <= F_NLSSORT ('漚')
THEN
V_RETURN := V_RETURN || 'O';
ELSIF V_COMPARE >= F_NLSSORT ('妑')
AND V_COMPARE <= F_NLSSORT ('曝')
THEN
V_RETURN := V_RETURN || 'P';
ELSIF V_COMPARE >= F_NLSSORT ('七')
AND V_COMPARE <= F_NLSSORT ('裠')
THEN
V_RETURN := V_RETURN || 'Q';
ELSIF V_COMPARE >= F_NLSSORT ('亽')
AND V_COMPARE <= F_NLSSORT ('鶸')
THEN
V_RETURN := V_RETURN || 'R';
ELSIF V_COMPARE >= F_NLSSORT ('仨')
AND V_COMPARE <= F_NLSSORT ('蜶')
THEN
V_RETURN := V_RETURN || 'S';
ELSIF V_COMPARE >= F_NLSSORT ('侤')
AND V_COMPARE <= F_NLSSORT ('籜')
THEN
V_RETURN := V_RETURN || 'T';
ELSIF V_COMPARE >= F_NLSSORT ('屲')
AND V_COMPARE <= F_NLSSORT ('鶩')
THEN
V_RETURN := V_RETURN || 'W';
ELSIF V_COMPARE >= F_NLSSORT ('夕')
AND V_COMPARE <= F_NLSSORT ('鑂')
THEN
V_RETURN := V_RETURN || 'X';
ELSIF V_COMPARE >= F_NLSSORT ('丫')
AND V_COMPARE <= F_NLSSORT ('韻')
THEN
V_RETURN := V_RETURN || 'Y';
ELSIF V_COMPARE >= F_NLSSORT ('帀')
AND V_COMPARE <= F_NLSSORT ('咗')
THEN
V_RETURN := V_RETURN || 'Z';
END IF;
END LOOP;
RETURN V_RETURN;
END;
END;