本文整理汇总了C#中System.Data.OleDb.OleDbDataReader.CreateAccessors方法的典型用法代码示例。如果您正苦于以下问题:C# OleDbDataReader.CreateAccessors方法的具体用法?C# OleDbDataReader.CreateAccessors怎么用?C# OleDbDataReader.CreateAccessors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.OleDbDataReader
的用法示例。
在下文中一共展示了OleDbDataReader.CreateAccessors方法的2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: DumpToSchemaTable
internal void DumpToSchemaTable(UnsafeNativeMethods.IRowset rowset) {
List<MetaData> metainfo = new List<MetaData>();
object hiddenColumns = null;
using (OleDbDataReader dataReader = new OleDbDataReader(_connection, _command, Int32.MinValue, 0)) {
dataReader.InitializeIRowset(rowset, ChapterHandle.DB_NULL_HCHAPTER, IntPtr.Zero);
dataReader.BuildSchemaTableInfo(rowset, true, false);
hiddenColumns = GetPropertyValue(ODB.DBPROP_HIDDENCOLUMNS); // MDAC 55611, 72106
if (0 == dataReader.FieldCount) {
return;
}
Debug.Assert(null == dataReader._fieldNameLookup, "lookup already exists");
FieldNameLookup lookup = new FieldNameLookup(dataReader, -1);
dataReader._fieldNameLookup = lookup;
// This column, together with the DBCOLUMN_GUID and DBCOLUMN_PROPID
// columns, forms the ID of the column. One or more (but not all) of these columns
// will be NULL, depending on which elements of the DBID structure the provider uses.
MetaData columnidname = dataReader.FindMetaData(ODB.DBCOLUMN_IDNAME);
MetaData columnguid = dataReader.FindMetaData(ODB.DBCOLUMN_GUID);
MetaData columnpropid = dataReader.FindMetaData(ODB.DBCOLUMN_PROPID);
MetaData columnname = dataReader.FindMetaData(ODB.DBCOLUMN_NAME);
MetaData columnordinal = dataReader.FindMetaData(ODB.DBCOLUMN_NUMBER);
MetaData dbtype = dataReader.FindMetaData(ODB.DBCOLUMN_TYPE);
MetaData columnsize = dataReader.FindMetaData(ODB.DBCOLUMN_COLUMNSIZE);
MetaData numericprecision = dataReader.FindMetaData(ODB.DBCOLUMN_PRECISION);
MetaData numericscale = dataReader.FindMetaData(ODB.DBCOLUMN_SCALE);
MetaData columnflags = dataReader.FindMetaData(ODB.DBCOLUMN_FLAGS);
MetaData baseschemaname = dataReader.FindMetaData(ODB.DBCOLUMN_BASESCHEMANAME);
MetaData basecatalogname = dataReader.FindMetaData(ODB.DBCOLUMN_BASECATALOGNAME);
MetaData basetablename = dataReader.FindMetaData(ODB.DBCOLUMN_BASETABLENAME);
MetaData basecolumnname = dataReader.FindMetaData(ODB.DBCOLUMN_BASECOLUMNNAME);
MetaData isautoincrement = dataReader.FindMetaData(ODB.DBCOLUMN_ISAUTOINCREMENT);
MetaData isunique = dataReader.FindMetaData(ODB.DBCOLUMN_ISUNIQUE);
MetaData iskeycolumn = dataReader.FindMetaData(ODB.DBCOLUMN_KEYCOLUMN);
// @devnote: because we want to use the DBACCESSOR_OPTIMIZED bit,
// we are required to create the accessor before fetching any rows
dataReader.CreateAccessors(false);
ColumnBinding binding;
while (dataReader.ReadRowset()) {
dataReader.GetRowDataFromHandle();
MetaData info = new MetaData();
binding = columnidname.columnBinding; // MDAC 72627
if (!binding.IsValueNull()) {
info.idname = (string)binding.Value();
info.kind = ODB.DBKIND_NAME;
}
binding = columnguid.columnBinding;
if (!binding.IsValueNull()) {
info.guid = binding.Value_GUID();
info.kind = ((ODB.DBKIND_NAME == info.kind) ? ODB.DBKIND_GUID_NAME : ODB.DBKIND_GUID);
}
binding = columnpropid.columnBinding;
if (!binding.IsValueNull()) {
info.propid = new IntPtr(binding.Value_UI4());
info.kind = ((ODB.DBKIND_GUID == info.kind) ? ODB.DBKIND_GUID_PROPID : ODB.DBKIND_PROPID);
}
binding = columnname.columnBinding;
if (!binding.IsValueNull()) {
info.columnName = (string)binding.Value();
}
else {
info.columnName = "";
}
if (4 == ADP.PtrSize) {
info.ordinal = (IntPtr)columnordinal.columnBinding.Value_UI4();
}
else {
info.ordinal = (IntPtr)columnordinal.columnBinding.Value_UI8();
}
short wType = unchecked((short) dbtype.columnBinding.Value_UI2());
if (4 == ADP.PtrSize) {
info.size = unchecked((int) columnsize.columnBinding.Value_UI4()); // WebData 99298
}
else {
info.size = ADP.IntPtrToInt32((IntPtr)unchecked((long)columnsize.columnBinding.Value_UI8()));
}
binding = numericprecision.columnBinding;
if (!binding.IsValueNull()) {
info.precision = (byte)binding.Value_UI2();
}
binding = numericscale.columnBinding;
if (!binding.IsValueNull()) {
info.scale = (byte)binding.Value_I2();
}
//.........这里部分代码省略.........
示例2: DumpToSchemaTable
internal void DumpToSchemaTable(System.Data.Common.UnsafeNativeMethods.IRowset rowset)
{
List<System.Data.OleDb.MetaData> list = new List<System.Data.OleDb.MetaData>();
object propertyValue = null;
using (OleDbDataReader reader = new OleDbDataReader(this._connection, this._command, -2147483648, CommandBehavior.Default))
{
reader.InitializeIRowset(rowset, ChapterHandle.DB_NULL_HCHAPTER, IntPtr.Zero);
reader.BuildSchemaTableInfo(rowset, true, false);
propertyValue = this.GetPropertyValue(0x102);
if (reader.FieldCount == 0)
{
return;
}
FieldNameLookup lookup = new FieldNameLookup(reader, -1);
reader._fieldNameLookup = lookup;
System.Data.OleDb.MetaData data20 = reader.FindMetaData("DBCOLUMN_IDNAME");
System.Data.OleDb.MetaData data19 = reader.FindMetaData("DBCOLUMN_GUID");
System.Data.OleDb.MetaData data18 = reader.FindMetaData("DBCOLUMN_PROPID");
System.Data.OleDb.MetaData data17 = reader.FindMetaData("DBCOLUMN_NAME");
System.Data.OleDb.MetaData data12 = reader.FindMetaData("DBCOLUMN_NUMBER");
System.Data.OleDb.MetaData data16 = reader.FindMetaData("DBCOLUMN_TYPE");
System.Data.OleDb.MetaData data11 = reader.FindMetaData("DBCOLUMN_COLUMNSIZE");
System.Data.OleDb.MetaData data15 = reader.FindMetaData("DBCOLUMN_PRECISION");
System.Data.OleDb.MetaData data14 = reader.FindMetaData("DBCOLUMN_SCALE");
System.Data.OleDb.MetaData data13 = reader.FindMetaData("DBCOLUMN_FLAGS");
System.Data.OleDb.MetaData data10 = reader.FindMetaData("DBCOLUMN_BASESCHEMANAME");
System.Data.OleDb.MetaData data9 = reader.FindMetaData("DBCOLUMN_BASECATALOGNAME");
System.Data.OleDb.MetaData data8 = reader.FindMetaData("DBCOLUMN_BASETABLENAME");
System.Data.OleDb.MetaData data7 = reader.FindMetaData("DBCOLUMN_BASECOLUMNNAME");
System.Data.OleDb.MetaData data6 = reader.FindMetaData("DBCOLUMN_ISAUTOINCREMENT");
System.Data.OleDb.MetaData data5 = reader.FindMetaData("DBCOLUMN_ISUNIQUE");
System.Data.OleDb.MetaData data4 = reader.FindMetaData("DBCOLUMN_KEYCOLUMN");
reader.CreateAccessors(false);
while (reader.ReadRowset())
{
reader.GetRowDataFromHandle();
System.Data.OleDb.MetaData item = new System.Data.OleDb.MetaData();
ColumnBinding columnBinding = data20.columnBinding;
if (!columnBinding.IsValueNull())
{
item.idname = (string) columnBinding.Value();
item.kind = 2;
}
columnBinding = data19.columnBinding;
if (!columnBinding.IsValueNull())
{
item.guid = columnBinding.Value_GUID();
item.kind = (2 == item.kind) ? 0 : 6;
}
columnBinding = data18.columnBinding;
if (!columnBinding.IsValueNull())
{
item.propid = new IntPtr((long) columnBinding.Value_UI4());
item.kind = (6 == item.kind) ? 1 : 5;
}
columnBinding = data17.columnBinding;
if (!columnBinding.IsValueNull())
{
item.columnName = (string) columnBinding.Value();
}
else
{
item.columnName = "";
}
if (4 == ADP.PtrSize)
{
item.ordinal = (IntPtr) data12.columnBinding.Value_UI4();
}
else
{
item.ordinal = (IntPtr) data12.columnBinding.Value_UI8();
}
short dbType = (short) data16.columnBinding.Value_UI2();
if (4 == ADP.PtrSize)
{
item.size = (int) data11.columnBinding.Value_UI4();
}
else
{
item.size = ADP.IntPtrToInt32((IntPtr) data11.columnBinding.Value_UI8());
}
columnBinding = data15.columnBinding;
if (!columnBinding.IsValueNull())
{
item.precision = (byte) columnBinding.Value_UI2();
}
columnBinding = data14.columnBinding;
if (!columnBinding.IsValueNull())
{
item.scale = (byte) columnBinding.Value_I2();
}
item.flags = (int) data13.columnBinding.Value_UI4();
bool isLong = IsLong(item.flags);
bool isFixed = IsFixed(item.flags);
NativeDBType type = NativeDBType.FromDBType(dbType, isLong, isFixed);
item.type = type;
if (data6 != null)
{
columnBinding = data6.columnBinding;
if (!columnBinding.IsValueNull())
//.........这里部分代码省略.........