Access mdb字段类型获取

相信不会再用到

https://www.daniweb.com/programming/software-development/threads/373942/getoledbschematable-data-types

https://www.w3schools.com/asp/prop_para_type.asp

COLUMN_NAME
CHARACTER_MAXIMUM_LENGTH
COLUMN_FLAGS
COLUMN_HASDEFAULT
character_octet_length
NUMERIC_PRECISION
NUMERIC_SCALE
IS_NULLABLE
TABLE_NAME
ORDINAL_POSITION
DATA_TYPE

string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source =" + address;
myConn = new OleDbConnection(strCon);

myConn.Open();
//foreach (DataRow r in myConn.GetSchema("Tables").Select("TABLE_TYPE = 'TABLE'"))
//{
//    tables.Add(r["TABLE_NAME"].ToString());
//}
//DataTable schema = myConn.GetSchema("Columns");
//foreach (DataRow row in schema.Rows)
//{
//    cols.Add(row.Field<string>("COLUMN_NAME"));
//    tbls.Add(row.Field<string>("TABLE_NAME"));
//}


DataTable schemaTable = myConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new Object[] { null, null, null, "TABLE" });
//List the table name from each row in the schema table.
//for (int i = 0; i < schemaTable.Rows.Count; i++)
//{
//    string Current_Str = schemaTable.Rows[i].ItemArray[2].ToString();
//}
DataTable tableColumns = myConn.GetOleDbSchemaTable(OleDbSchemaGuid.Columns, new object[] { null, null, "cfdj", null });
foreach (DataRow row in tableColumns.Rows)
{
    var columnNameColumn = row["COLUMN_NAME"];
    var dateTypeColumn = row["DATA_TYPE"];
    var ordinalPositionColumn = row["ORDINAL_POSITION"];
}


StringBuilder sbColumnDetails = new StringBuilder();
foreach (DataColumn column in schemaTable.Columns)
{
    sbColumnDetails.Append("Column Name: ");
    sbColumnDetails.Append(column.ColumnName);

    sbColumnDetails.Append(" ");

    sbColumnDetails.Append("Column DataType: ");
    sbColumnDetails.Append(column.DataType.ToString());

    sbColumnDetails.Append(" || ");
}

Constant	Value	Description
adEmpty	0	No value
adSmallInt	2	A 2-byte signed integer.
adInteger	3	A 4-byte signed integer.
adSingle	4	A single-precision floating-point value.
adDouble	5	A double-precision floating-point value.
adCurrency	6	A currency value
adDate	7	The number of days since December 30, 1899 + the fraction of a day.
adBSTR	8	A null-terminated character string.
adIDispatch	9	A pointer to an IDispatch interface on a COM object. Note: Currently not supported by ADO.
adError	10	A 32-bit error code
adBoolean	11	A boolean value.
adVariant	12	An Automation Variant. Note: Currently not supported by ADO.
adIUnknown	13	A pointer to an IUnknown interface on a COM object. Note: Currently not supported by ADO.
adDecimal	14	An exact numeric value with a fixed precision and scale.
adTinyInt	16	A 1-byte signed integer.
adUnsignedTinyInt	17	A 1-byte unsigned integer.
adUnsignedSmallInt	18	A 2-byte unsigned integer.
adUnsignedInt	19	A 4-byte unsigned integer.
adBigInt	20	An 8-byte signed integer.
adUnsignedBigInt	21	An 8-byte unsigned integer.
adFileTime	64	The number of 100-nanosecond intervals since January 1,1601
adGUID	72	A globally unique identifier (GUID)
adBinary	128	A binary value.
adChar	129	A string value.
adWChar	130	A null-terminated Unicode character string.
adNumeric	131	An exact numeric value with a fixed precision and scale.
adUserDefined	132	A user-defined variable.
adDBDate	133	A date value (yyyymmdd).
adDBTime	134	A time value (hhmmss).
adDBTimeStamp	135	A date/time stamp (yyyymmddhhmmss plus a fraction in billionths).
adChapter	136	A 4-byte chapter value that identifies rows in a child rowset
adPropVariant	138	An Automation PROPVARIANT.
adVarNumeric	139	A numeric value (Parameter object only).
adVarChar	200	A string value (Parameter object only).
adLongVarChar	201	A long string value.
adVarWChar	202	A null-terminated Unicode character string.
adLongVarWChar	203	A long null-terminated Unicode string value.
adVarBinary	204	A binary value (Parameter object only).
adLongVarBinary	205	A long binary value.
AdArray	0x2000	A flag value combined with another data type constant. Indicates an array of that other data type.