IBM DB2 Control Loop

Question

我正在從MS SQL Server遷移到IBM DB2（版本9.7）。試圖寫一個複合SQL循環和局部變量（不存儲過程的一部分），有點像 -

BEGIN ATOMIC 
    DECLARE i INT DEFAULT 12; 
    WHILE i > 0 
    "DO ...."; 
    SET COUNT = COUNT - 1; 
    END WHILE; 
END 

但我得到一個錯誤只是在第一行聲明變量 -

SQL0104N An unexpected token "12" was found following "ECLARE I INT DEFAULT". Expected tokens may include: "END-OF-STATEMENT" 

任何幫助是極大的讚賞。

Answer 1

我假設你的問題與語句終結者有關（更容易看到你是否提供了你得到的實際錯誤）。我測試了以下，它的工作原理如下：

[ ... ]$ cat aa.sql 

CREATE TABLE TEMP_ITERATIONS (X VARCHAR(50)) @ 

BEGIN ATOMIC 
    DECLARE i INT DEFAULT 12; 
    WHILE i > 0 DO 
     INSERT INTO TEMP_ITERATIONS VALUES ('IT'|| RTRIM(CHAR(i))); 
     SET i = i - 1; 
    END WHILE; 
END @ 

[ ... ]$ db2 -td@ -f aa.sql 

DB20000I The SQL command completed successfully. 
DB20000I The SQL command completed successfully. 

[ ... ]$ db2 "select * from TEMP_ITERATIONS" 

X             
-------------------------------------------------- 
IT12            
IT11            
IT10 
[...] 
12 record(s) selected. 

這裏我用@作爲語句終止符;有特殊的意義。如果你不想改變語句終結者的一個訣竅是「隱藏」在行尾添加註釋，在複合語句裏面：

[ ... ]$ cat aa.sql 

CREATE TABLE TEMP_ITERATIONS (X VARCHAR(50)) ; 

BEGIN ATOMIC 
    DECLARE i INT DEFAULT 12; -- 
    WHILE i > 0 DO 
     INSERT INTO TEMP_ITERATIONS VALUES ('IT'|| RTRIM(CHAR(i))); -- 
     SET i = i - 1; -- 
    END WHILE; -- 
END ; 

[ ... ] db2 -tf aa.sql 
DB20000I The SQL command completed successfully. 
DB20000I The SQL command completed successfully. 

[ ... ]$ db2 "select * from TEMP_ITERATIONS" 

X             
-------------------------------------------------- 
IT12            
IT11            
IT10 
[...] 
12 record(s) selected.