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          ASCII
          Get The ASCII Value Of A Character ASCII(<string_or_column>)
          SELECT ASCII('A') FROM dual;
          SELECT ASCII('Z') FROM dual;
          SELECT ASCII('a') FROM dual;
          SELECT ASCII('z') FROM dual;
          SELECT ASCII(' ') FROM dual;
          ?
          CASE Related Functions
          Upper Case UPPER(<string_or_column>)
          SELECT UPPER('Dan Morgan') FROM dual;
          Lower Case LOWER(<string_or_column>)
          SELECT LOWER('Dan Morgan') FROM dual;
          Initial Letter Upper Case INITCAP(<string_or_column>)
          SELECT INITCAP('DAN MORGAN') FROM dual;
          NLS Upper Case NLS_UPPER(<string_or_column>)
          SELECT NLS_UPPER('Dan Morgan', 'NLS_SORT = XDanish')
          FROM dual;
          NLS Lower Case NLS_LOWER(<string_or_column>)
          SELECT NLS_LOWER('Dan Morgan', 'NLS_SORT = XFrench')
          FROM dual;
          NLS Initial Letter Upper Case NLS_INITCAP(<string_or_column>)
          SELECT NLS_INITCAP('DAN MORGAN', 'NLS_SORT = XGerman')
          FROM dual;
          ?
          CHR
          Character CHR(<ascii_string_or_column>>)
          SELECT(CHR(68) || CHR(65) || CHR(78)) FROM dual;

          SELECT(CHR(68) || CHR(97) || CHR(110)) FROM dual;
          ?
          COALESCE
          Returns the first non-null occurrence COALESCE(<value>, <value>, <value>, ...)
          CREATE TABLE test (
          col1? VARCHAR2(1),
          col2? VARCHAR2(1),
          col3? VARCHAR2(1));

          INSERT INTO test VALUES (NULL, 'B', 'C');
          INSERT INTO test VALUES ('A', NULL, 'C');
          INSERT INTO test VALUES (NULL, NULL, 'C');
          INSERT INTO test VALUES ('A', 'B', 'C');

          SELECT COALESCE(col1, col2, col3) FROM test;
          ?
          CONCAT
          Concatenate CONCAT(<first_string_or_column>>, <second_string_or_column>>)
          SELECT CONCAT('Dan ', 'Morgan') FROM dual;
          ?
          CONVERT
          Converts From One Character Set To Another CONVERT(<character>,<destination_character_set>,
          <source_character_set>)
          SELECT CONVERT('?????A B C D E','US7ASCII','WE8ISO8859P1')
          FROM dual;
          ?
          INSTR
          See links at page bottom
          ?
          LENGTH
          String Length LENGTH(<string_or_column>)
          SELECT LENGTH('Dan Morgan') FROM dual;
          ?
          LPAD
          Left Pad LPAD(<string_or_column>, <final_length>, <padding_character>)
          SELECT LPAD('Dan Morgan', 25, 'x') FROM dual;
          ?
          LTRIM
          Left Trim LTRIM(<string_or_column>)
          SELECT LTRIM('?? Dan Morgan?? ') FROM dual;
          ?
          NLSSORT
          Returns the string of bytes used to sort a string.

          The string returned is of RAW data type
          NLSSORT(<column_name>, 'NLS_SORT = <NLS Parameter>);
          CREATE TABLE test (name VARCHAR2(15));
          INSERT INTO test VALUES ('Gaardiner');
          INSERT INTO test VALUES ('Gaberd');
          INSERT INTO test VALUES ('G鈈erd');
          COMMIT;

          SELECT * FROM test ORDER BY name;

          SELECT * FROM test
          ORDER BY NLSSORT(name, 'NLS_SORT = XDanish');
          ?
          REPLACE
          See links at page bottom
          ?
          REVERSE
          Reverse REVERSE(<string_or_column>)
          SELECT REVERSE('Dan Morgan') FROM dual;

          SELECT DUMP('Dan Morgan') FROM dual;
          SELECT DUMP(REVERSE('Dan Morgan')) FROM dual;
          ?
          RPAD
          Right Pad RPAD(<string_or_column>, <final_length>, <padding_character>)
          SELECT RPAD('Dan Morgan', 25, 'x') FROM dual;
          ?
          RTRIM
          Right Trim RTRIM(<string_or_column>)
          SELECT RTRIM('?? Dan Morgan?? ') FROM dual;
          ?
          SOUNDEX

          Returns Character String Constaining The Phonetic Representation Of Another String
          Rules:
          • Retain the first letter of the string and remove all other occurrences of the following letters: a, e, h, i, o, u, w, y
          • Assign numbers to the remaining letters (after the first) as
            follows:
            b, f, p, v = 1
            c, g, j, k, q, s, x, z = 2
            d, t = 3
            l = 4
            m, n = 5
            r = 6
          • If two or more letters with the same number were adjacent in the original name (before step 1), or adjacent except for any intervening h and w, then omit all but the first.
          • Return the first four bytes padded with 0.

          SOUNDEX(<string_or_column>)

          CREATE TABLE test (
          name VARCHAR2(15));

          INSERT INTO test VALUES ('Smith');
          INSERT INTO test VALUES ('Smyth');
          INSERT INTO test VALUES ('Smythe');
          INSERT INTO test VALUES ('Smither');
          INSERT INTO test VALUES ('Smidt');
          INSERT INTO test VALUES ('Smick');
          INSERT INTO test VALUES ('Smiff');
          COMMIT;

          SELECT * FROM test;

          SELECT *
          FROM test
          WHERE SOUNDEX(name) = SOUNDEX('SMITH');
          ?
          SUBSTR
          See links at page bottom
          ?
          TRANSLATE
          See links at page bottom
          ?
          TREAT
          Changes The Declared Type Of An Expression TREAT (<expression> AS REF schema.type))?
          SELECT name, TREAT(VALUE(p) AS employee_t).salary SALARY?
          FROM persons p;
          ?
          TRIM (variations are LTRIM and RTRIM)
          Trim Spaces TRIM(<string_or_column>)
          SELECT '?? Dan Morgan ?? ' FROM dual;

          SELECT TRIM('?? Dan Morgan?? ') FROM dual;
          Trim Other Characters TRIM(<character_to_trim> FROM <string_or_column>)
          SELECT TRIM('D' FROM 'Dan Morgan') FROM dual;
          Trim By CHR value TRIM(<string_or_column>)
          SELECT ASCII(SUBSTR('Dan Morgan',1,1)) FROM dual;

          SELECT TRIM(CHR(68) FROM 'Dan Morgan') FROM dual;
          ?
          Vertical Bars
          Also known as Pipes <first_string> || <second_string>
          SELECT 'Dan' || ' ' || 'Morgan' FROM dual;

          with alias

          SELECT 'Dan' || ' ' || 'Morgan' NAME FROM dual;
          or
          SELECT 'Dan' || ' ' || 'Morgan' AS NAME FROM dual;
          ?
          VSIZE
          Byte Size VSIZE(<string_or_column>)
          SELECT VSIZE('Dan Morgan') FROM dual;
          ?
          Related Topics
          CASE
          DBMS_LOB
          Decode
          Instring
          Miscellaneous Functions
          Operators (Built-in)
          Regular Expressions
          Replace
          Substring
          Translate
          XML Functions
          posted on 2006-04-04 09:25 似水流年 閱讀(415) 評論(0)  編輯  收藏 所屬分類: Oracle
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