A Parameter object represents a parameter or argument associated with a Command object based on a parameterized query or stored procedure.
Remarks
Many providers support parameterized commands. These are commands where the desired action is defined once, but variables (or parameters) are used to alter some details of the command. For example, an SQL SELECT statement could use a parameter to define the matching criteria of a WHERE clause, and another to define the column name for a SORT BY clause.
Parameter objects represent parameters associated with parameterized queries, or the in/out arguments and the return values of stored procedures. Depending on the functionality of the provider, some collections, methods, or properties of a Parameter object may not be available.


Parameter 對(duì)象代表參數(shù)或與基于參數(shù)化查詢或存儲(chǔ)過(guò)程的 Command 對(duì)象相關(guān)聯(lián)的參數(shù)。


說(shuō)明
許多提供者都支持參數(shù)化的命令。需要進(jìn)行的操作在這些命令中只定義一次，但可以使用變量（或參數(shù)）改變命令的某些細(xì)節(jié)。例如，SQL SELECT 語(yǔ)句可使用某個(gè)參數(shù)定義 WHERE 子句的匹配條件，而使用另一個(gè)參數(shù)來(lái)定義 SORT BY 子句的列的名稱。
Parameter 對(duì)象代表與參數(shù)化查詢關(guān)聯(lián)的參數(shù)，或進(jìn)/出參數(shù)以及存儲(chǔ)過(guò)程的返回值。取決于提供者的功能，Parameter 對(duì)象的某些集合、方法或?qū)傩杂锌赡軣o(wú)效。