Question

我开始使用ADS sql表触发器来存储在一个特定表上完成的更改。这是一个想法：

//-------- sql trigger to store changes on patients table to auditLog Table
//----------------------------------------------------------------------
declare cChanges Char( 5000 );
declare allColumns Cursor ;
declare FieldName Char( 25 );
declare StrSql  Char( 255 );
declare @new cursor as select * from __new;
declare @old cursor as select * from __old; 
open @old; 
fetch @old;
open @new; 
fetch @new;
Set cChanges = '';
Open AllColumns as Select * from system.columns where parent = 'patients';
while fetch allColumns DO
// Try
   FieldName = allColumns.Name;
   StrSql = 'IF @new.'+FieldName
          + '<> @old.'+FieldName
          +' and @old.'+FieldName + '<> [ ] THEN ' 
                       + 'cChanges = Trim( '+cChanges+' ) + @old.'+FieldName
                                   + ' Changed to ' + '@new.'+fieldname
                                   + ' | '+ 'ENDIF ; ' ;
   Execute Immediate StrSql ;
//    Catch ALL
//    End Try;
End While;
if cChanges <> '' THEN
    Insert Into AuditLog ( TableKey, Patient, [table], [user], creation, Changes ) 
         values( @new.patient, @new.patient, [Patietns], User(), Now(), cChanges ) ;
ENDIF;
CLOSE AllColumns;
//--------------------------

报告变量cChanges的上述触发器代码错误不存在。

有人可以帮忙吗？

雷纳尔多。

Answer 1

我认为问题与动态SQl有关，试图设置触发器体中声明的值。

e.g。您的cChanges = TRIM(语句可能导致问题，因为cChanges不存在该上下文。

您应该使用绑定变量来完成此操作，而不是尝试使用=符号进行设置。

您可以在他们的文档中看到他们说您无法通过转到

直接访问这些变量

http://devzone.advantagedatabase.com/dz/webhelp/advantage9.1/advantage_sql/sql_psm_script/execute_immediate.htm

Answer 2

问题确实是您无法立即访问脚本中的本地变量。你能解决的问题是使用临时表：

//-------- sql trigger to store changes on patients table to auditLog Table
//----------------------------------------------------------------------
declare cChanges Char( 5000 );
declare allColumns Cursor ;
declare FieldName Char( 25 );
declare StrSql  Char( 255 );
Set cChanges = '';
Open AllColumns as Select * from system.columns where parent = 'patients';
while fetch allColumns DO
// Try
   FieldName = allColumns.Name;

   StrSql = 'SELECT n.FieldName newVal,'
            + 'o.FieldName oldVal '
            + 'INTO #MyTrigTable '
            + 'FROM __new n, __old o';

   EXECUTE IMMEDIATE strSQL;

   IF ( SELECT oldVal FROM #myTrigTable ) <> '' THEN
      IF ( SELECT newVal FROM #myTrigTable ) <> ( SELECT oldVal FROM #myTrigTable ) THEN
         cChanges = 'Construct_SomeThing_Using_#myTrigTable_or_a_cursorBasedOn#MyTrigTable';
         INSERT INTO AuditLog ( TableKey, Patient, [table], [user], creation, Changes ) 
         SELECT patient, patient, 'Patietns', User(), Now(), cChages FROM __new ;
      END;
   END;
   DROP TABLE #myTrigTable;
//    Catch ALL
//    End Try;
End While;
CLOSE AllColumns;
//--------------------------

Sql触发器将更改保存到审计跟踪表

2 个答案: