操作関数はDUAL表とかで確認すればいいんだよ。
SELECT
SUBSTR('社員表-A001',0,length('社員表-A001') - 2) AS 後ろから２文字は削除する,
REPLACE(INITCAP('ABC_DEF'), '_' , '') AS INITCAP,
to_single_byte('ａａａａ') as 半角文字列に変換,
to_multi_byte('akaak') as 全角文字列に変換,
to_char(systimestamp, 'YYYYMMDDHH24MISSFF') as ミリ秒,
'１行目' || chr(13) || '２行目' as windows_改行,
'１行目' || chr(10) || '２行目' as unix_改行,
TO_NUMBER('01') 文字列数字をソートするときなど,
TO_CHAR('1','009') AS TOCHAR,
SUBSTR('社員表-A001',-6,3) AS SUBSTR,
LENGTH('ジョーンズ') AS LENGTH,
LENGTH(TRIM(TO_CHAR('200000','99G999G999'))) AS TEST,
LENGTH(TO_CHAR('200000','99G999G999')) AS TESTA,
INITCAP('ABC DE-F=G23HI+J5MN') AS INITCAP,
UPPER('ORACLE 9I') AS UPPER,
LOWER('ORACLE 9I') AS LOWER,
CONCAT('社員番号','氏名') AS CONCAT,
('社員番号' || '氏名') AS 連結演算子
, REPLACE('2003/01','/','') AS REPLACETEST
, RPAD('MO',12,'--') as "RPAD example"
FROM
DUAL
ORDER BY
TO_NUMBER('01') asc,
to_char(1, '009') descめも：あと、sql文の長さ約4000字が最大
