我在我的數據庫中有3-4個表，我想跟蹤其中的更改。數據庫中多個表的審計歷史記錄
我主要關心更新。
每當更新發生時，我想將先前的條目（值或完整的行）存儲在審計表中。
基本列我在想如下：
AuditId, TableName, PK1, PK2, PK3, PKVal1, PKVal2, PKVal3, UpdateType, PrevEntryJSON
JSON將是格式：Key:Value和我寧願用它去爲列不斷變化，我想保留的所有值，即使他們不要改變。
其他選項是刪除JSON與100個名稱與不同列（所有表的累積）相同的列。
我想聽聽人們對此的看法。我怎麼能改進它，我可以面對什麼問題？
通過觸發器可能不是最好的方式，但我對它開放。
感謝，
我看到一個很有效執行本肚裏如下：
TABLE audit_entry (
audit_entry_id INTEGER PRIMARY KEY,
audit_entry_type VARCHAR2(10) NOT NULL,
-- ^^ stores 'INSERT'/'UPDATE' --/'DELETE'
table_name VARCHAR2(30) NOT NULL,
-- ^^ stores the name of the table that is changed
column_name VARCHAR2(30) NOT NULL,
-- ^^ stores the name of the column that is changed
primary_key_id INTEGER NOT NULL,
-- ^^ Primary key ID to identify the row that is changed
-- Below are the actual values that are changed.
-- If the changed column is a foreign key ID then
-- below columns tell you which is new and which is old
old_id INTEGER,
new_id INTEGER,
-- If the changed column is of any other numeric type,
-- store the old and new values here.
-- Modify the precision and scale of NUMBER as per your
-- choice.
old_number NUMBER(18,2),
new_number NUMBER(18,2),
-- If the changed column is of date type, with or without
-- time information, store it here.
old_ts TIMESTAMP,
new_ts TIMESTAMP,
-- If the changed column is of VARCHAR2 type,
-- store it here.
old_varchar VARCHAR2(2000),
new_varchar VARCHAR2(2000),
...
... -- Any other columns to store data of other types,
... -- e.g., blob, xmldata, etc.
...
)
我們創建一個簡單的順序，給我們新的增量整數值audit_entry_id：
CREATE SEQUENCE audit_entry_id_seq;
像audit_entry這樣的表的美麗之處在於您可以存儲有關所有類型DML的信息INSERT，UPDATE和DELETE在同一個地方。
例如，對於插入，請將old_*列保留爲空，並用您的值填充new_*。
對於更新，每當它們被更改時，填充old_*和new_*列。
對於刪除，只填寫old_*列並保留new_*爲空。
當然，輸入適當的值爲audit_entry_type。 0）
然後，例如，您有一個表像如下：
TABLE emp (
empno INTEGER,
ename VARCHAR2(100) NOT NULL,
date_of_birth DATE,
salary NUMBER(18,2) NOT NULL,
deptno INTEGER -- FOREIGN KEY to, say, department
...
... -- Any other columns that you may fancy.
...
)
在此表只需創建一個觸發如下：
CREATE OR REPLACE TRIGGER emp_rbiud
-- rbiud means Row level, Before Insert, Update, Delete
BEFORE INSERT OR UPDATE OR DELETE
ON emp
REFERENCING NEW AS NEW OLD AS OLD
DECLARE
-- any variable declarations that deem fit.
BEGIN
WHEN INSERTING THEN
-- Of course, you will insert empno.
-- Let's populate other columns.
-- As emp.ename is a not null column,
-- let's insert the audit entry value directly.
INSERT INTO audit_entry(audit_entry_id,
audit_entry_type,
table_name,
column_name,
primary_key,
new_varchar)
VALUES(audit_entry_id_seq.nextval,
'INSERT',
'EMP',
'ENAME',
:new.empno,
:new.ename);
-- Now, as date_of_birth may contain null, we do:
IF :new.date_of_birth IS NOT NULL THEN
INSERT INTO audit_entry(audit_entry_id,
audit_entry_type,
table_name,
column_name,
primary_key,
new_ts)
VALUES(audit_entry_id_seq.nextval,
'INSERT',
'EMP',
'DATE_OF_BIRTH',
:new.empno,
:new.date_of_birth);
END IF;
-- Similarly, code DML statements for auditing other values
-- as per your requirements.
WHEN UPDATING THEN
-- This is a tricky one.
-- You must check which columns have been updated before you
-- hurry into auditing their information.
IF :old.ename != :new.ename THEN
INSERT INTO audit_entry(audit_entry_id,
audit_entry_type,
table_name,
column_name,
primary_key,
old_varchar,
new_varchar)
VALUES(audit_entry_id_seq.nextval,
'INSERT',
'EMP',
'ENAME',
:new.empno,
:old.ename,
:new.ename);
END IF;
-- Code further DML statements in similar fashion for other
-- columns as per your requirement.
WHEN DELETING THEN
-- By now you must have got the idea about how to go about this.
-- ;0)
END;
/
只是一個謹慎的話：是有選擇地選擇你要審覈的表和列，因爲無論如何，你這張表將有大量的行。此表格中的SELECT聲明將比您預期的要慢。
我真的很想看到任何其他類型的實施，因爲這將是一個很好的學習經驗。希望你的問題能得到更多的答案，因爲這是我見過的審計表的最佳實現，我仍在尋找使其更好的方法。