本文整理汇总了C#中System.Data.OleDb.OleDbConnection.SupportSchemaRowset方法的典型用法代码示例。如果您正苦于以下问题：C# OleDbConnection.SupportSchemaRowset方法的具体用法？C# OleDbConnection.SupportSchemaRowset怎么用？C# OleDbConnection.SupportSchemaRowset使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类System.Data.OleDb.OleDbConnection的用法示例。
在下文中一共展示了OleDbConnection.SupportSchemaRowset方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C#代码示例。
示例1: DeriveParametersFromStoredProcedure
// known difference: when getting the parameters for a sproc, the
// return value gets marked as a return value but for a sql stmt
// the return value gets marked as an output parameter.
static private OleDbParameter[] DeriveParametersFromStoredProcedure(OleDbConnection connection, OleDbCommand command) {
OleDbParameter[] plist = new OleDbParameter[0];
if (connection.SupportSchemaRowset(OleDbSchemaGuid.Procedure_Parameters)) {
string quotePrefix, quoteSuffix;
connection.GetLiteralQuotes(ADP.DeriveParameters, out quotePrefix, out quoteSuffix);
Object[] parsed = MultipartIdentifier.ParseMultipartIdentifier(command.CommandText, quotePrefix, quoteSuffix, '.', 4, true, Res.OLEDB_OLEDBCommandText, false); // MDAC 70930
if (null == parsed[3]) {
throw ADP.NoStoredProcedureExists(command.CommandText);
}
Object[] restrictions = new object[4];
object value;
// Parse returns an enforced 4 part array
// 0) Server - ignored but removal would be a run-time breaking change from V1.0
// 1) Catalog
// 2) Schema
// 3) ProcedureName
// Restrictions array which is passed to OleDb API expects:
// 0) Catalog
// 1) Schema
// 2) ProcedureName
// 3) ParameterName (leave null)
// Copy from Parse format to OleDb API format
Array.Copy(parsed, 1, restrictions, 0, 3);
//if (cmdConnection.IsServer_msdaora) {
// restrictions[1] = Convert.ToString(cmdConnection.UserId).ToUpper();
//}
DataTable table = connection.GetSchemaRowset(OleDbSchemaGuid.Procedure_Parameters, restrictions);
if (null != table) {
DataColumnCollection columns = table.Columns;
DataColumn parameterName = null;
DataColumn parameterDirection = null;
DataColumn dataType = null;
DataColumn maxLen = null;
DataColumn numericPrecision = null;
DataColumn numericScale = null;
DataColumn backendtype = null;
int index = columns.IndexOf(ODB.PARAMETER_NAME);
if (-1 != index) parameterName = columns[index];
index = columns.IndexOf(ODB.PARAMETER_TYPE);
if (-1 != index) parameterDirection = columns[index];
index = columns.IndexOf(ODB.DATA_TYPE);
if (-1 != index) dataType = columns[index];
index = columns.IndexOf(ODB.CHARACTER_MAXIMUM_LENGTH);
if (-1 != index) maxLen = columns[index];
index = columns.IndexOf(ODB.NUMERIC_PRECISION);
if (-1 != index) numericPrecision = columns[index];
index = columns.IndexOf(ODB.NUMERIC_SCALE);
if (-1 != index) numericScale = columns[index];
index = columns.IndexOf(ODB.TYPE_NAME); // MDAC 72315
if (-1 != index) backendtype = columns[index];
DataRow[] dataRows = table.Select(null, ODB.ORDINAL_POSITION_ASC, DataViewRowState.CurrentRows); // MDAC 70928
plist = new OleDbParameter[dataRows.Length];
for(index = 0; index < dataRows.Length; ++index) {
DataRow dataRow = dataRows[index];
OleDbParameter parameter = new OleDbParameter();
if ((null != parameterName) && !dataRow.IsNull(parameterName, DataRowVersion.Default)) {
// $
parameter.ParameterName = Convert.ToString(dataRow[parameterName, DataRowVersion.Default], CultureInfo.InvariantCulture).TrimStart(new char[] { '@', ' ', ':'});
}
if ((null != parameterDirection) && !dataRow.IsNull(parameterDirection, DataRowVersion.Default)) {
short direction = Convert.ToInt16(dataRow[parameterDirection, DataRowVersion.Default], CultureInfo.InvariantCulture);
parameter.Direction = ConvertToParameterDirection(direction);
}
if ((null != dataType) && !dataRow.IsNull(dataType, DataRowVersion.Default)) {
// need to ping FromDBType, otherwise WChar->WChar when the user really wants VarWChar
short wType = Convert.ToInt16(dataRow[dataType, DataRowVersion.Default], CultureInfo.InvariantCulture);
parameter.OleDbType = NativeDBType.FromDBType(wType, false, false).enumOleDbType;
}
if ((null != maxLen) && !dataRow.IsNull(maxLen, DataRowVersion.Default)) {
parameter.Size = Convert.ToInt32(dataRow[maxLen, DataRowVersion.Default], CultureInfo.InvariantCulture);
}
switch(parameter.OleDbType) {
case OleDbType.Decimal:
case OleDbType.Numeric:
case OleDbType.VarNumeric:
if ((null != numericPrecision) && !dataRow.IsNull(numericPrecision, DataRowVersion.Default)) {
// @devnote: unguarded cast from Int16 to Byte
parameter.PrecisionInternal = (Byte) Convert.ToInt16(dataRow[numericPrecision], CultureInfo.InvariantCulture);
//.........这里部分代码省略.........