Schema Collections

The Schema collections return metadata for the Advanced SQL Engine objects. The notable metadata columns for the MBR data type are:

Schema Table

The TdDataReader.SchemaTable returns result set metadata. The notable metadata columns for the MBR data type transformed to VarChar(256) are:

Configuring Parameters

The following example shows how to configure a MBR parameter using DbType type declaration and a BCL value. The value is set to a System.String instance.

TdParameter shapeMBR = new TdParameter();
shapeMBR.ParameterName = "shapeMBR";

shapeMBR.DbType = DbType.String;

shapeMBR.Value = "(10, 3, 22, 7)";

The following example shows how to configure a MBR parameter using TdType type declaration and a BCL value.

TdParameter shapeMBR = new TdParameter();
shapeMBR.ParameterName = "shapeMBR";

shapeMBR.TdType = TdType.VarChar;

shapeMBR.Value = "(10, 3, 22, 7)";

The TdParameter.Value should be set to an Array of Characters (Char[]), String object or an object that supports conversion (Convert.ToString) to System.String.

Set TdParameter.Size Property for InputOutput or Output Parameters

The TdParameter.Size property must be set to 256 for InputOutput or Output Parameters. The Data Provider will throw an exception when TdParameter.Direction property is set to ParameterDirection.Output or ParameterDirection.InputOutput and TdParameter.Size property is set to Zero. The TdParameter.Size property specifies the maximum number of Unicode Characters (or Bytes) the Data Provider will send to the SQL Engine and/or will receive from the SQL Engine. 

Note
TdParameter.Size is not required for Input parameters. However it will improve the overall performance of Batch Updates. Therefore the general guideline is to always set the TdParameter.Size property to 256.

Retrieving MBR Data

The following methods and properties return the column or parameter value as a System.Char[] object.

1. TdDataReader.GetChars
2. TdDataReader.GetFieldValue<Char[]>
3. TdParameter.GetValue<Char[]>

The following methods and properties return the column or parameter value as a System.String object.

1. TdDataReader.GetString
2. TdDataReader.GetValue
3. TdDataReader.GetProviderSpecificValue
4. TdDataReader.GetFieldValue<String>
5. TdParameter.Value
6. TdParameter.GetValue<String>

See Also

Data Type Mappings

Accessor Methods for Retrieving Data

Configuring Parameters and Parameter Data Types