我目前要讀取 infomix 資料庫, sql 指令如下 select * from server1:table1 a, server2:table2 b where (a.field1 = b.field2) 但是我不管用 ADO 或 BDE 的資料庫元件, 都無法執行這到指令, 都會出現一個 unknow type 的錯誤訊息, 不過我用 Sql Explorer 卻能正確執行, 請問這要如何解呢?

您好， 試試把 Query 的 ParamCheck 設成 false ，看有沒有用 ?

我將 ParamCheck 設成 false 之後, 已經可以確實的執行了, 不過查詢的速度卻很慢, 不知改變這個參數的作用和影響的東西有哪些??

應該和效率無關，只是略過 paramater 的檢查而已，以下是原文說明  

引言: Description Set ParamCheck to specify whether or not the Parameters property is initialized using ":Param" style parameters in an SQL statement specified in the CommandText property. If the SQL statement in CommandText only contains "?" style parameters, the Parameters property will only be initialized if the OLE DB provider returns parameter information for an SQL command. Otherwise, the parameters must be explicitly created using the CreateParameter method (TParameters). When ParamCheck is true, a parameter is generated for each ":Param" style parameter in the SQL statement. The default value of ParamCheck is true. This property is useful for data definition language (DDL) statements that contain parameters as part of the DDL statement and that are not parameters for the ADO command component. For example, the DDL statement to create a stored procedure may contain parameter statements that are part of the stored procedure. Set ParamCheck to false to prevent these parameters from being mistaken for parameters of the ADO command component executing the DDL statement.

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