序列和觸發器PL/SQL腳本用於在表上自動生成ID

Question

有人可以幫助我修復該代碼。它不會在PL/SQL上運行（SQLPLUS @ script.sql），給出 SP2-0552：未聲明綁定變量「NEW」。

Script.SQL

prompt Creating Table SYSTEMDATALOG; 

declare 
    counter1 integer; 
    counter2 integer; 

begin 
    SELECT COUNT(*) INTO counter1 FROM ALL_TABLES WHERE TABLE_NAME='SYSTEMDATALOG' AND OWNER='MZMESDB'; 

    if counter1 = 1 then 
     DROP TABLE SYSTEMDATALOG; 
    end if; 

    SELECT COUNT(*) INTO counter2 FROM ALL_SEQUENCES WHERE SEQUENCE NAME='SEQSYSTEMDATALOG'; 

    if counter2 = 1 then 
     DROP SEQUENCE SEQSYSTEMDATALOGID; 
    endif; 

    CREATE TABLE "MZMESDB"."SYSTEMDATALOG" ("ID" INTEGER NOT NULL , 
         "DATETIME" DATE NOT NULL , 
         "TYPE" VARCHAR2(64) NOT NULL, 
         "SEVERITY" INTEGER NOT NULL, 
         "SOURCE" VARCHAR2(64) NOT NULL, 
         "USER" VARCHAR2(64) NOT NULL, 
         "MESSAGE" VARCHAR2(1024), PRIMARY KEY ("ID") VALIDATE); 


    CREATE SEQUENCE SEQSYSTEMDATALOGID; 

    CREATE OR REPLACE TRIGGER TRIGSYSTEMDATALOGID 
     BEFORE INSERT ON SYSTEMDATALOG 
     FOR EACH ROW 
      BEGIN 
       SELECT SEQSYSTEMDATALOGID.NEXTVAL INTO :NEW.ID FROM DUAL; 
      END TRIGSYSTEMDATALOGID; 
end; 
/

提前感謝任何形式的幫助。

[DEFINITIVE CODE]

提示創建表SYSTEMDATALOG;

申報 counter1 integer; counter2整數; SELECT COUNT（*）INTO counter1 FROM ALL_TABLES WHERE TABLE_NAME ='SYSTEMDATALOG'AND OWNER ='MZMESDB';其中，

if counter1 = 1 then 
    execute immediate 'DROP TABLE SYSTEMDATALOG'; 
end if; 

SELECT COUNT(*) INTO counter2 FROM ALL_SEQUENCES WHERE SEQUENCE_NAME='SEQSYSTEMDATALOG'; 

IF counter2 = 1 then 
    execute immediate 'DROP SEQUENCE SEQSYSTEMDATALOGID'; 
END IF; 

execute immediate 'CREATE TABLE "MZMESDB"."SYSTEMDATALOG" ( 
        "ID" INTEGER NOT NULL , 
        "DATETIME" DATE NOT NULL , 
        "TYPE" VARCHAR2(64) NOT NULL, 
        "SEVERITY" INTEGER NOT NULL, 
        "SOURCE" VARCHAR2(64) NOT NULL, 
        "USER" VARCHAR2(64) NOT NULL, 
        "MESSAGE" VARCHAR2(1024), PRIMARY KEY ("ID") VALIDATE)'; 

execute immediate 'CREATE SEQUENCE SEQSYSTEMDATALOGID'; 

execute immediate 'CREATE OR REPLACE TRIGGER TRIGSYSTEMDATALOGID 
      BEFORE INSERT ON SYSTEMDATALOG 
      FOR EACH ROW 
      BEGIN 
      SELECT SEQSYSTEMDATALOGID.NEXTVAL INTO :NEW.ID FROM DUAL; 
      END TRIGSYSTEMDATALOGID;'; 

end;

Answer 1

一個問題是您正在混合PL/SQL（匿名PL/SQL塊）和DDL。雖然可以在PL/SQL中編寫DML語句（SELECT/INSERT/UPDATE/DELETE），但不能直接在PL/SQL中編寫DDL（CREATE/DROP等）。

您需要在匿名PL/SQL塊之外運行您的DDL語句或使用 EXECUTE IMMEDIATE '<statement>';。

至於在:NEW上的錯誤，我認爲它會消失，當你解決其他問題。如果沒有，試着加入：

SET SCAN OFF

在SQL * PLUS文件的開頭。