小编Abu*_*aeb的帖子

我有两个表和一个触发器，并且正在ProjectsTable像这样插入值：

CREATE TABLE ProjectsTable
(
  ProjectID     NUMBER(6) NOT NULL,
  ProjectName   VARCHAR2(200) NOT NULL,
  Cost      NUMBER(10,2),
  ExpenseTotal  NUMBER(10,2),
  CostRemaining     NUMBER(10,2),
  PRIMARY KEY (ProjectID)
);

CREATE TABLE ExpenseTable
(
  ID            NUMBER(6) NOT NULL,
  ProjectID     NUMBER(6) NOT NULL,
  ExpenseAmount NUMBER(10,2),
  ExpenseDate   NUMBER(4),
  CONSTRAINT fk
  FOREIGN KEY (ProjectID)
  REFERENCES ProjectsTable(ProjectID)  
); 

CREATE TRIGGER ExpenseSum AFTER INSERT ON ExpenseTable FOR EACH ROW
BEGIN
    UPDATE ProjectsTable P
    SET ExpenseTotal = 
    (SELECT SUM(ExpenseAmount) from ExpenseTable
    where ExpenseTable.ProjectID= P.ProjectID)
    where P.ProjectID = :New.ProjectID;
END;
/

INSERT …