后续版本的 Microsoft SQL Server 将删除该功能。请避免在新的开发工作中使用该功能，并着手修改当前还在使用该功能的应用程序。
The ColumnMaxLength property exposes the maximum number of characters required to store the data of a column in the current result set of a QueryResults object.
语法
object
.ColumnMaxLength(
OrdinalColumn
)
Parts
- object
An expression that evaluates to an object in the Applies To list.
- OrdinalColumn
A long integer that specifies the column in the results by position.
Data Type
String
Modifiable
Read-only
Prototype (C/C++)
HRESULT GetColumnMaxLength(long nColumn, LPLONG pRetVal);
备注
Interpret the value of the ColumnMaxLength property with respect to the data type of the column in the result set. Retrieve the data type using the ColumnType property.
| ColumnType property | ColumnMaxLength |
|---|---|
SQLDMO_DTypeBinary, SQLDMO_DTypeGUID, SQLDMO_DTypeImage, SQLDMO_DTypeNText, SQLDMO_DTypeText, or SQLDMO_DTypeVarBinary |
A system-defined value. Use the GetColumnBinaryLength method to determine the length of a specified row value. |
SQLDMO_DTypeBit, SQLDMO_DTypeFloat8, SQLDMO_DTypeInt1, SQLDMO_DTypeInt2, SQLDMO_DTypeInt4, SQLDMO_DTypeMoney, or SQLDMO_DTypeMoney4 |
The maximum precision of a value of the type. |
SQLDMO_DTypeChar, SQLDMO_DTypeVarchar, SQLDMO_DTypeUChar, or SQLDMO_DTypeUVarchar |
The count of bytes required to represent the data as a Unicode character string (two bytes per character). The count is incremented to include the count of bytes in a string terminator. |
SQLDMO_DTypeDateTime or SQLDMO_DTypeDateTime4 |
A system-defined value. |