Oracle提取中文字符串拼音首字母函数

/* 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;