ALTER TABLE 表å?? { ADD COLUMN 列定義 | ADD CONSTRAINT節 | DROP [ COLUMN ] 列å?? [ CASCADE | RESTRICT ] DROP { PRIMARY KEY | FOREIGN KEY 制約å?? | UNIQUE 制約å?? | CHECK 制約å?? | CONSTRAINT 制約å?? } ALTER [ COLUMN ] 列定義変更 | LOCKSIZE { ROW | TABLE } }
å?˜ç´”列å?? データ型 [ 列å?˜ä½?制約 ]* [ [ WITH ] DEFAULT 既定制約å¼? ]
既定制約å¼?ã?®è©³ç´°ã?«ã?¤ã?„ã?¦ã?¯ã€?列ã?®æ—¢å®šã‚’å?‚ç…§ã?—ã?¦ã??ã? ã?•ã?„。
列å?? SET DATA TYPE VARCHAR(integer) | column-name SET INCREMENT BY 定整数 | column-name RESTART WITH 定整数 | column-name [ NOT ] NULL | column-name [ WITH ] DEFAULT 既定値
列定義変更ã?®SET INCREMENT BY 定整数ã?«ã‚ˆã‚Šã€?è˜åˆ¥å?列ã?®ã?¨ã‚‹é€£ç¶šã?—ã?Ÿå€¤ã?®é–“éš”ã?Œè¨å®šã?•れã?¾ã?™ã€‚è˜åˆ¥å?列ã?Œã?¨ã‚‹æ¬¡ã?®å€¤ã?¯ã€?最後ã?«ã?¨ã‚‰ã‚Œã?Ÿå€¤ã?«å¢—分ã?ŒåŠ ç®—ã?•れã?Ÿå€¤ã?¨ã?ªã‚Šã?¾ã?™ã€‚ã?“ã?®å ´å?ˆåˆ—ã?«ã?¯ã?‚らã?‹ã?˜ã‚?IDENTITY属性ã?Œå®šç¾©ã?•れã?¦ã?„ã?ªã?‘れã?°ã?ªã‚Šã?¾ã?›ã‚“。
CREATE TABLE tauto(i INT GENERATED BY DEFAULT AS IDENTITY, k INT) CREATE UNIQUE INDEX tautoInd ON tauto(i) INSERT INTO tauto(k) values 1,2
INSERT INTO tauto VALUES (3,3) INSERT INTO tauto VALUES (4,4) INSERT INTO tauto VALUES (5,5)
ALTER TABLE tauto ALTER COLUMN i RESTART WITH 6
ALTER TABLE ã?¯è¡¨ã‚’å?‚ç…§ã?™ã‚‹ã?„ã?‹ã?ªã‚‹ãƒ“ューã?«ã‚‚影響ã?—ã?¾ã?›ã‚“。ã?“れã?¯SELECT一覧ã?«"*"ã‚’æŒ?ã?£ã?¦ã?„ã?¦ã‚‚然りã?§ã?™ã€‚æ–°ã?—ã??è¿½åŠ ã?•れã?Ÿåˆ—ã?Œãƒ“ューã?‹ã‚‰è¦‹ã?ˆã‚‹ã‚ˆã?†ã?«ã?™ã‚‹ç‚ºã?«ã?¯ã€?ãƒ“ãƒ¥ãƒ¼ã‚’ç ´æ£„ã?—ã?¦ä½œã‚Šç›´ã?•ã?ªã?‘れã?°ã?ªã‚Šã?¾ã?›ã‚“。
è¿½åŠ ã?™ã‚‹åˆ—ã?®åˆ—定義ã?¯ã€?æ§‹æ–‡ã?®ä¸Šã?§CREATE TABLEæ–‡ã?®åˆ—ã?¨å?Œã?˜ã?§ã?™ã€‚ã?§ã?™ã?‹ã‚‰ã€?列ã?®åˆ¶ç´„ã‚’ALTER TABLE ADD COLUMNæ–‡ã?®æ–°ã?—ã?„列ã?«æ›¸ã??ã?“ã?¨ã‚‚ã?§ã??ã?¾ã?™ã€‚ã?—ã?‹ã?—ã?ªã?Œã‚‰ã€?æ—¢å˜ã?®ãƒ†ãƒ¼ãƒ–ルã?«NOT NULL制約ã?®ã?‚ã‚‹åˆ—ã‚’è¿½åŠ ã?™ã‚‹ã?“ã?¨ã?¯ã€?ã??ã?®åˆ—ã?«æ—¢å®šå€¤ã‚’与ã?ˆã?Ÿå ´å?ˆã?®ã?¿å?¯èƒ½ã?§ã?™ã€‚ã?•ã‚‚ã?ªã?‘れã?°ã€?ALTER TABLEæ–‡ã?Œå®Ÿè¡Œã?•れã?Ÿã?¨ã??ã€?例外ã?Œç™ºç”Ÿã?—ã?¾ã?™ã€‚
CREATE TABLEã?¨å?Œæ§˜ã€?列定義ã?«ä¸€æ„?ã?‚ã‚‹ã?„ã?¯ä¸»ã‚ー制約ã?Œã?‚ã‚‹å ´å?ˆã€?列ã?¯null値をã?¨ã‚‹ã?“ã?¨ã?Œã?§ã??ã?¾ã?›ã‚“。ã?—ã?Ÿã?Œã?£ã?¦ã€?NOT NULL属性も必è¦?ã?§ã?™ã€‚(SQLSTATE 42831)
ALTER TABLE ADD UNIQUEã‚„PRIMARY KEYã?¯ã€?å?˜ä¸€ã?®åˆ—ã?«ã‚ˆã‚‹ä¸»ã‚ーを定義ã?™ã‚‹ç°¡å?˜ã?ªæ–¹æ³•ã‚’æ??ä¾›ã?—ã?¾ã?™ã€‚ã‚‚ã?—PRIMARY KEYã?ŒCã?¨ã?„ã?†åˆ—ã?®å®šç¾©ã?«æ›¸ã?‹ã‚Œã?Ÿã?•れã?Ÿå ´å?ˆã€?ã?“れã?¯PRIMARY KEY(C)ã?¨ã?„ã?†åˆ¥ã?®ç¯€ã?«æ›¸ã?„ã?Ÿã?®ã?¨å?Œã?˜ã?§ã?™ã€‚列ã?¯nullã?®å€¤ã‚’ã?¨ã?£ã?¦ã?¯ã?ªã‚‰ã?ªã?„ã?®ã?§ã€?NOT NULL属性も指定ã?•れã?ªã?‘れã?°ã?ªã‚Šã?¾ã?›ã‚“。
制約ã?®æ§‹æ–‡ã?«ã?¤ã?„ã?¦ã?®è©³ç´°ã?¯ã€?CONSTRAINT 節をèªã‚“ã?§ã??ã? ã?•ã?„。 ADD TABLE ADD CONSTRAINTã?¨ã?„ã?†æ›¸ã??æ–¹ã?«ã?¦ã€?åˆ¶ç´„ã‚’è¿½åŠ ã?™ã‚‹å ´å?ˆã?¯ã€?表毎ã?®åˆ¶ç´„ã?®æ§‹æ–‡ã?«å¾“ã?£ã?¦ã??ã? ã?•ã?„。
ALTER TABLE DROP COLUMNã?«ã‚ˆã‚Šã€?表ã?‹ã‚‰åˆ—ã‚’ç ´æ£„ã?§ã??ã?¾ã?™ã€‚
COLUMNã?¨ã?„ã?†ã‚ーワードã?¯ç„¡ã??ã?¦ã‚‚ã?‹ã?¾ã?„ã?¾ã?›ã‚“。
CASCADEã‚„RESTRICTã‚‚ã€?ç„¡ã??ã?¦ã?‹ã?¾ã?„ã?¾ã?›ã‚“。ã?©ã?¡ã‚‰ã‚‚指定ã?—ã?ªã?‹ã?£ã?Ÿå ´å?ˆã€?既定ã?¯CASCADEã?§ã?™ã€‚
RESTRICTã?®å ´å?ˆã€?ä¾?å˜ã?—ã?¦ã?„るスã‚ーマã?®æƒ…å ±ã?Œç„¡åйã?«ã?ªã‚‹ã?ªã‚‰ã?°ã€?列ã?®ç ´æ£„ã?¯å¤±æ•—ã?—ã?¾ã?™ã€‚
CASCADEã?®å ´å?ˆã€?列ã?®ç ´æ£„ã?¨ä½µã?›ã?¦ã€?無効ã?«ã?ªã‚‹ã‚¹ã‚ーマã?®æƒ…å ±ã‚‚ç ´æ£„ã?•れã?¾ã?™ã€‚
DROP COLUMN RESTRICTã?Œå¤±æ•—ã?™ã‚‹åŽŸå› ã?¨ã?ªã‚‹ã‚¹ã‚ーマã?®æƒ…å ±ã?«ã?¯ã€?次ã?Œå?«ã?¾ã‚Œã?¾ã?™ã€‚ ビューã€?トリガã€?主ã‚ー制約ã€?外部ã‚ー制約ã€?一æ„?ã‚ー制約ã€?ãƒ?ェック制約ã€?列権é™?ã€‚ç ´æ£„ã?™ã‚‹åˆ—ã?«ä¾?å˜ã?™ã‚‹ã?„ã?šã‚Œã?‹ã?®æƒ…å ±ã?Œã?‚れã?°ã€?DROP COLUMN RESTRICTã?¯å¤±æ•—ã?—ã?¾ã?™ã€‚
表ã?«ã?²ã?¨ã?¤ã?—ã?‹ã?ªã?„列ã?¯ã€?ç ´æ£„ã?™ã‚‹ã?“ã?¨ã?Œã?§ã??ã?¾ã?›ã‚“。
sqlAuthorizationã?ŒçœŸã?§ã?‚ã‚‹å ´å?ˆã€?列を削除ã?™ã‚‹ã?“ã?¨ã?¯ã?§ã??ã?¾ã?›ã‚“。(DERBY-1909ã‚’å?‚ç…§ã?—ã?¦ã??ã? ã?•ã?„。) )
列ã?Œç´¢å¼•ã?«ã?¦ä½¿ã‚?れã?¦ã?„ã‚‹ã?‹å?¦ã?‹ã?«ã?‹ã?‹ã‚?らã?šã€?列ã?®ç ´æ£„ã?¯CASCADE/RESTRICTã?®ã?©ã?¡ã‚‰ã?§ã‚‚å?Œã?˜ã‚ˆã?†ã?«è¡Œã‚?れã?¾ã?™ã€‚列ã?Œç ´æ£„ã?•れるã?¨ã??ã€?索引ã?«ã?‚ã‚‹ã??ã?®åˆ—ã?Œå?–り除ã?‹ã‚Œã?¾ã?™ã€‚ã??ã?®åˆ—ã?Œç´¢å¼•ã?«ã?‚ã‚‹ã?Ÿã? ã?²ã?¨ã?¤ã?®åˆ—ã?§ã?‚ã?£ã?Ÿå ´å?ˆã€?索引全体ã?Œç ´æ£„ã?•れã?¾ã?™ã€‚
ALTER TABLE DROP CONSTRAINTã?«ã‚ˆã‚Šè¡¨ã?®åˆ¶ç´„ã‚’ç ´æ£„ã?§ã??ã?¾ã?™ã€‚å??å‰?付ã?‘ã?—ã?¦ã?„ã?ªã?„åˆ¶ç´„ã‚’ç ´æ£„ã?™ã‚‹ã?Ÿã‚?ã?«ã?¯ã€?SYS.SYSCONSTRAINTSã?«è¨˜éŒ²ã?•れã?¦ã?„る自動生æˆ?ã?•れã?Ÿåˆ¶ç´„ã?®å??å‰?をデリミトã?•れã?Ÿè˜åˆ¥å?ã?¨ã?—ã?¦æŒ‡å®šã?™ã‚‹å¿…è¦?ã?Œã?‚りã?¾ã?™ã€‚
主ã‚ー・一æ„?性・外部ã‚ãƒ¼åˆ¶ç´„ã‚’ç ´æ£„ã?™ã‚‹ã?¨ã€?ã??ã?®åˆ¶ç´„ã?Œæ©Ÿèƒ½ã?™ã‚‹ã?Ÿã‚?ã?«å˜åœ¨ã?—ã?¦ã?„る索引ã?Œç ´æ£„ã?•れã?¾ã?™ã€‚(ã?“ã?®ç´¢å¼•ã?¯æ”¯æ?´ç´¢å¼•ã?¨ã‚‚呼ã?°ã‚Œã?¾ã?™ã€‚)
ã?“れらã?®åˆ—ã?®å¹…を増やã?™ã?Ÿã‚?ã?«ã?¯ã€?データ型ã?¨æ–°ã?—ã?„サイズを列å??ã?®å¾Œã?«æ›¸ã??ã?¾ã?™ã€‚
列ã?®å¹…を減らã?—ã?Ÿã‚Šã€?データ型を変更ã?—ã?Ÿã‚Šã?™ã‚‹äº‹ã?¯ã?§ã??ã?¾ã?›ã‚“。主ã‚ーã?®ä¸€éƒ¨ã‚„ã€?外部ã‚ー制約ã?‹ã‚‰å?‚ç…§ã?•れã?¦ã?„る一æ„?ã‚ーã€?外部ã‚ー制約ã?®ä¸€éƒ¨ã?§ã?‚る列ã?®å¹…ã?¯å¤‰æ›´ã?§ã??ã?¾ã?›ã‚“。
è˜åˆ¥å?列ã?®ã?¨ã‚‹é€£ç¶šã?—ã?Ÿå€¤ã?®é–“隔をè¨å®šã?™ã‚‹ã?Ÿã‚?ã?«ã?¯ã€?定整数を与ã?ˆã?¾ã?™ã€‚ã?‚らã?‹ã?˜ã‚?列ã?«ã?¯è˜åˆ¥å?属性ã?Œä¸Žã?ˆã‚‰ã‚Œã?¦ã?„ã?ªã?‘れã?°ã?ªã‚Šã?¾ã?›ã‚“。(SQLSTATE 42837)ã‚‚ã?—表ã?«æ—¢ã?«è¡Œã?Œã?‚ã‚‹å ´å?ˆã€?列ã?®SET INCREMENT defaultã?ŒåŠ ç®—ã?•れã?Ÿå€¤ã?¯å¤‰æ›´ã?•れã?¾ã?›ã‚“。
NOT NULL制約を既å˜ã?®åˆ—ã?«ä¸Žã?ˆã‚‹ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚ã?“れを行ã?†å ´å?ˆã€?æ—¢å˜ã?®NULL値ã?Œè¡¨ã?®ã??ã?®åˆ—ã?«å˜åœ¨ã?—ã?¦ã?¯ã?ªã‚Šã?¾ã?›ã‚“。
NOT NULL制約を既å˜ã?®åˆ—ã?‹ã‚‰å?–り除ã??ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚ã?“れを行ã?†å ´å?ˆã€?ã??ã?®åˆ—ã?ŒPRIMARY KEYã‚„UNIQUEã?®åˆ¶ç´„ã?«ã?¦ä½¿ã‚?れã?¦ã?„る列ã?§ã?‚ã?£ã?¦ã?¯ã?ªã‚Šã?¾ã?›ã‚“。
æ–°è¦?ã?®åˆ—ã?«æ—¢å®šå€¤ã‚’与ã?ˆã‚‹ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚既定値ã?¨ã?¯å€¤ã?ŒæŒ‡å®šã?•れã?ªã?‹ã?£ã?Ÿå ´å?ˆã?«åˆ—ã?«æŒ¿å…¥ã?•れる値ã?§ã?™ã€‚ã‚‚ã?—明示的ã?«æ—¢å®šå€¤ã?Œä¸Žã?ˆã‚‰ã‚Œã?¦ã?„ã?ªã?‹ã?£ã?Ÿå ´å?ˆã€?列ã?®æ—¢å®šå€¤ã?¯NULLã?§ã?™ã€‚ã‚‚ã?—æ–°ã?—ã?„列ã?«æ—¢å®šå€¤ã‚’与ã?ˆã?Ÿå ´å?ˆã€?表ã?«ã?‚ã‚‹æ—¢å˜ã?®è¡Œã?¯ã??ã?®æ–°åˆ—ã?«æ—¢å®šå€¤ã‚’ã?¨ã‚‹ã?“ã?¨ã?¨ã?ªã‚Šã?¾ã?™ã€‚
既定値ã?®ã‚ˆã‚Šè©³ç´°ã?ªæƒ…å ±ã?«ã?¤ã?„ã?¦ã?¯ã€?CREATE TABLE 文をå?‚ç…§ã?—ã?¦ã??ã? ã?•ã?„。
ã‚‚ã?—ã?‚ã?ªã?Ÿã?®ã‚·ã‚¹ãƒ†ãƒ ã?Œæ—¢å®šã?®è¨å®šã?§ã?‚る行毎ã?®ãƒãƒƒã‚¯ã‚’行ã?†ã?®ã?§ã?‚れã?°ã€?LOCKSIZE節ã?«ã‚ˆã‚Šè¡¨ã?®è¡Œæ¯Žã?®ãƒãƒƒã‚¯ã‚’上書ã??ã?™ã‚‹ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚(一方ã?‚ã?ªã?Ÿã?®ã‚·ã‚¹ãƒ†ãƒ ã?Œè¡¨ã?”ã?¨ã?®ãƒãƒƒã‚¯ã‚’行ã?†ã‚ˆã?†è¨å®šã?•れã?¦ã?„ã‚‹å ´å?ˆã€?Derbyã?ŒLOCKSIZE節ã?«å¯¾ã?—ã?¦ä¾‹å¤–を投ã?’ã?ªã?‹ã?£ã?Ÿã?¨ã?—ã?¦ã‚‚ã€?ãƒãƒƒã‚¯ã?®ç²’度を行å?˜ä½?ã?®ãƒãƒƒã‚¯ã?«å¤‰æ›´ã?™ã‚‹ã?“ã?¨ã?¯ã?§ã??ã?¾ã?›ã‚“。) 表ã?®è¡Œæ¯Žã?®ãƒãƒƒã‚¯ã‚’上書ã??ã?™ã‚‹ã?«ã?¯ã€?表ã?«ãƒãƒƒã‚¯ã?®è¨å®šã‚’行ã?„ã?¾ã?™ã€‚ ã‚‚ã?—表ã?Œè¡¨æ¯Žã?®ãƒãƒƒã‚¯ã?§ä½œæˆ?ã?•れã?Ÿå ´å?ˆã€?ALTER TABLEæ–‡ã?«ã?¦LOCKSIZE節を使ã?†ã?“ã?¨ã?§ã€?ã??ã?®è¨å®šã‚’行毎ã?®è¨å®šã?«æˆ»ã?™ã?“ã?¨ã?Œã?§ã??ã?¾ã?™ã€‚ã?“れã?Œä¾¿åˆ©ã?ªå ´å?ˆã‚‚ã?‚ã‚‹ã?®ã?§ã?™ã?Œã€?ã??ã?®è©³ç´°ã?«ã?¤ã?„ã?¦ã?¯ã€?Derbyã?®ãƒ?ューニングをå?‚ç…§ã?—ã?¦ã??ã? ã?•ã?„。
-- æ—¢å˜ã?®è¡¨ã?«åˆ—ã?”ã?¨ã?®åˆ¶ç´„ã?®ã?‚ã‚‹åˆ—ã‚’è¿½åŠ ã?™ã‚‹ã€‚ -- 表ã?«æ—¢å˜è¡Œã?Œã?‚ã?£ã?Ÿå ´å?ˆã€?æ—¢å˜è¡Œã?®æ–°åˆ—ã?¯NULLã‚’ã?¨ã‚‹ã?®ã?§ã€? -- 例外ã?Œç™ºç”Ÿã?™ã‚‹ã€‚ ALTER TABLE CITIES ADD COLUMN REGION VARCHAR(26) CONSTRAINT NEW_CONSTRAINT CHECK (REGION IS NOT NULL); -- æ—¢å˜ã?®è¡¨ã?«ä¸€æ„?æ€§åˆ¶ç´„ã‚’è¿½åŠ ã?™ã‚‹ã€‚ -- é‡?複ã?—ã?Ÿã‚ーã?Œã?‚ã?£ã?Ÿå ´å?ˆã€?例外ã?Œç™ºç”Ÿã?™ã‚‹ã€‚ ALTER TABLE SAMP.DEPARTMENT ADD CONSTRAINT NEW_UNIQUE UNIQUE (DEPTNO); -- Cities表ã?«å¤–部ã‚ãƒ¼åˆ¶ç´„ã‚’è¿½åŠ ã?™ã‚‹ã€‚ -- 行ã?Œåˆ¶ç´„を満ã?Ÿã?™ã?‹æ¤œè¨¼ã?•れã?¦ã€? -- ã‚‚ã?—制約を満ã?Ÿã?•ã?ªã?„行ã?Œè¦‹ã?¤ã?‹ã?£ã?Ÿå ´å?ˆã€? -- 制約ã?¯è¿½åŠ ã?•れã?ªã?„。 ALTER TABLE CITIES ADD CONSTRAINT COUNTRY_FK Foreign Key (COUNTRY) REFERENCES COUNTRIES (COUNTRY); -- 主ã‚ー制約を表ã?«è¿½åŠ ã?™ã‚‹ã€‚ -- 最åˆ?ã?«è¡¨ã?Œä½œæˆ?ã?•れる。 CREATE TABLE ACTIVITIES (CITY_ID INT NOT NULL, SEASON CHAR(2), ACTIVITY VARCHAR(32) NOT NULL); -- ã‚‚ã?—主ã‚ーã?¨ã?—ã?Ÿåˆ—ã?«nullã‚„é‡?複ã?—ã?Ÿå€¤ã?Œã?‚ã‚‹å ´å?ˆã€? -- ã?“ã?®åˆ¶ç´„ã‚’è¿½åŠ ã?™ã‚‹ã?“ã?¨ã?¯ã?§ã??ã?ªã?„。 ALTER TABLE Activities ADD PRIMARY KEY (city_id, activity); -- ã‚‚ã?—ä¾?å˜ã?™ã‚‹æƒ…å ±ã?Œç„¡ã?‘れã?°ã€?city_id列ã?Œç ´æ£„ã?•れる。 ALTER TABLE Cities DROP COLUMN city_id RESTRICT; -- ä¾?å˜ã?™ã‚‹æƒ…å ±ã?¨ä½µã?›ã?¦ã€?city_id列ã?Œç ´æ£„ã?•れる。 ALTER TABLE Cities DROP COLUMN city_id CASCADE; -- CITIES表ã?®ä¸»ã‚ãƒ¼åˆ¶ç´„ã‚’ç ´æ£„ã?™ã‚‹ã€‚ ALTER TABLE Cities DROP CONSTRAINT Cities_PK; -- CITIES表ã?®å¤–部ã‚ãƒ¼åˆ¶ç´„ã‚’ç ´æ£„ã?™ã‚‹ã€‚ ALTER TABLE Cities DROP CONSTRAINT COUNTRIES_FK; -- 既定値を1ã?«ã?¨ã‚‹DEPTNOåˆ—ã‚’è¿½åŠ ã?™ã‚‹ã€‚ ALTER TABLE SAMP.EMP_ACT ADD COLUMN DEPTNO INT DEFAULT 1; -- VARCHARåž‹ã?®åˆ—幅を増やã?™ã€‚ ALTER TABLE SAMP.EMP_PHOTO ALTER PHOTO_FORMAT SET DATA TYPE VARCHAR(30); -- 表ã?®ãƒãƒƒã‚¯ç²’度を変更ã?™ã‚‹ã€‚ ALTER TABLE SAMP.SALES LOCKSIZE TABLE; -- MANAGER列ã?®NOT NULLåˆ¶ç´„ã‚’ç ´æ£„ã?™ã‚‹ã€‚ ALTER TABLE Employees ALTER COLUMN Manager NULL; -- SSN列ã?«NOT NULLåˆ¶ç´„ã‚’è¿½åŠ ã?™ã‚‹ã€‚ ALTER TABLE Employees ALTER COLUMN ssn NOT NULL; -- SALARY列ã?®æ—¢å®šå€¤ã‚’変更ã?™ã‚‹ã€‚ ALTER TABLE Employees ALTER COLUMN Salary DEFAULT 1000.0
ALTER TABLE æ–‡ã?«ã‚ˆã‚Šå¤‰æ›´ã?™ã‚‹è¡¨ã?«ä¾?å˜ã?™ã‚‹å…¨ã?¦ã?®æ–‡ã?¯ã€?次回ã?®å®Ÿè¡Œã?«ã?¦å†?コンパイルã?•れã?¾ã?™ã€‚ã‚‚ã?—変更ã?™ã‚‹è¡¨ã‚’å?‚ç…§ã?™ã‚‹ã€?é–‹ã?„ã?Ÿã‚«ãƒ¼ã‚½ãƒ«ã?Œã?‚ã‚‹å ´å?ˆã€?ALTER TABLEã?¯è¨±å?¯ã?•れã?¾ã?›ã‚“。