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我有疑问，如何在 Intersystems Cache 中执行类似触发器的操作。情况：例如，我有带有属性（列）valueA，valueB 的表 X，我想在 valueA 被 UPDATE 更改时更新 valueB。我已经定义了全局变量 ^VALUEBGENER 并使用它来增加它的 $SEQ 函数，我的想法是：

Class User.X Extends %Persistent [ ClassType = persistent, DdlAllowed, Final, Owner = {_SYSTEM}, ProcedureBlock, SqlRowIdPrivate, SqlTableName = X]
{
    Property VALUEA As %Library.String(MAXLEN = 8) [ Required,SqlColumnumber = 1];
    Property VALUEB As %Library.Integer(MAXVAL = 2147483647, MINVAL = -2147483648) [ Required,SqlColumnNumber = 1,SqlComputed,SqlColumnumber = 2, SqlComputeCode = {SET {valueB}=$SEQ(^VALUEBGENER)}, SqlComputeOnChange = %%UPDATE];
}

但它不起作用，当我改变 valuea 但它在我改变 valueb 时起作用，知道吗？PS对不起英语不好

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1 回答 1

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可以通过添加触发器来实现，以及SqlCompute

    Class User.X Extends %Persistent [ ClassType = persistent, DdlAllowed, Final, Owner = {_SYSTEM}, ProcedureBlock, SqlRowIdPrivate, SqlTableName = X]
    {
        Property VALUEA As %Library.String(MAXLEN = 8) [ Required, SqlComputed,SqlColumnumber = 1];
        Property VALUEB As %Library.Integer(MAXVAL = 2147483647, MINVAL = -2147483648) [ Required,InitialExpression=0,SqlColumnNumber = 2, SqlComputeCode = {SET {*}=$SEQ(^VALUEB)}, SqlComputeOnChange = %%UPDATE ];
        Trigger[Event=Update]{
           NEW valuebx
           new rowid
           set rowid={ID}
           SET valuebx= 0
           // {fieldname*C} evaluates to 1 if the field has been changed and 0 
           if({VALUEA*C}=1){
             // we trigger sql computeCode and inc of global variable by update
             //and it doesnt matter what is here in :valuebx
               &sql(update x set valueb=:valuebx WHERE ROWID=:rowid)
           }
        }
    }
于 2018-08-13T18:46:27.033 回答