| Data Provider | Parameter format |
| sqlclient | @parametername |
| oledb | ? mark |
| odbc | ? mark |
| oracleclient | : parametername |
各种数据库参数是不同的，如上表格为对应关系
| .net framework type | dbtype | sqldbtype | oledbtype | odbctype | oracletype |
| Boolean | Boolean | bit | boolean | bit | byte |
| byte | byte | tinyint | unsignedtinyint | tinyint | byte |
| char | char | char | char | ||
| datetime | datetime | datetime | datetimestamp | datetime | datetime |
| decimal | decimal | decimal | decimal | numeric | number |
| double | double | float | double | double | double |
| single | single | real | single | real | float |
| guid | guid | uniqueidentifier | guid | uniqueidentifier | raw |
| int16 | int16 | smallint | smallint | smallint | int16 |
| int32 | int32 | int | int | int | int32 |
| int64 | int64 | bigint | bigint | bigint | number |
| string | string | nvarchar(max 4000) | varwchar | nvarchar | nvarchar |
更详细对比请看如下链接