informixvsoracle中英文(參考版)
2025-05-15 08:43本頁面
【正文】 4） IFX: OPEN …USING FOREACH ….. ORA:FOREACH … USING 5) USING后若參數(shù)是常數(shù)，會有錯誤，可以將該常數(shù)附給一個變數(shù)，再用該變數(shù)作為參數(shù) 6） DECLARE CURSOR段中的 ”O(jiān)RDER BY…” 改為 ” ORDER BY…” （空一格） （針對以上種種，總結出的一般修改步驟如下） 1）找到關于 ROWID的定義，將 INTEGER改為 CHAR(18) 2) 找到 _cur(),_b()中定義的 DECLARE,加上SQL,END SQL，做成 SQL BLOCK 的模式，并將其中 ROWID前加 $ 3)找到 OUTER , 在 OUTER TABLE 中的字段前加上 tab_name； 4）查詢 GROUP BY ,ORDER BY ,WITH HOLD做相應修改即可。Y39。Y39。N39。139。N39。139。y39。Y39。[Yy]39。99939。999999999939。012345678939。[09][09][09]39。 2）若組 SQL時， MATCHES后為變數(shù)，可用 cl_parse()。tex39。Some text39。RO39。RO39。R39。RO39。 Data Types Convert INFORMIX data types to ORACLE data types : 2. ROWID ? INFORMIX中為 INTEGER ? ORACLE中為 CHAR(18) ROWIDs INFORMIX rowids are INTEGERs while ORACLE rowids are provided as CHAR(18). ORACLE ROWIDs are physical addresses of the rows. Example of ORACLE 8 rowid : AAAA8mAALAAAAQkAAA 3. OUTER JOINS ? IFX: A,OUTER B … WHERE A01=B01 ? ORA:A,B … WHERE A01= Outer joins INFORMIX SQL SELECT ... FROM a, OUTER(b) WHERE = SELECT ... FROM a, OUTER(b,OUTER(c)) WHERE = AND = AND = ORACLE expects the (+) operator in the join condition SELECT ... FROM a, b WHERE = (+) SELECT ... FROM a, b, c WHERE = (+) AND = (+) AND = (+) 1. Example which does not work : FROM OUTER(tab2), tab1 . 2. Example : WHERE = . 3. Example : SELECT ... UNION SELECT or SELECT ... WHERE col IN (SELECT...) Restrictions 4. Pessimistic Locking ? DECLARE .. FOR UPDATE 的語句 不要加 WITH HOLD ? IFX: DECLARE … FOR UPDATE ORA: DECALRE .. SQL……. FOR UPDATE NOWAIT END SQL ? IFX: OPEN ORA: OPEN FETCH IF … IF …. FETCH…. Pessimistic locking Informix DECLARE cc CURSOR FOR SELECT ... FOR UPDATE [OF collist] OPEN cc FETCH cc lock is acquired CLOSE cc lock is released ?The row must be fetched in order to set the lock. ?If the cursor is local to a transaction, the lock is released when transaction ends. If the cursor is declared WITH HOLD, the lock is released when the the cursor is
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