Schema Collections

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

Column Name	Description
COLUMN_TYPE or DATA_TYPE	Set to INTERVAL HOUR.
FORMAT	Format assigned to the SQL Engine object.
PROVIDERDBTYPE	It is set to TdType.IntervalHour.
INTERVAL_PRECISION	The maximum number of digits for the Hour component.

Schema Table

The TdDataReader.SchemaTable returns result set metadata. The notable metadata columns for the Interval Hour data type are:

Column Name	Description
NumericPrecision	The maximum number of digits for the Hour component.
DataType	System.Type object for the System.TimeSpan structure.
ProviderType	Set to TdType.IntervalHour.
Format	Format assigned to the SQL Engine object.
ProviderSpecificDataType	System.Type object for the TdIntervalHour structure.

Configuring Parameters

The following example shows how to configure an Interval Hour parameter using DbType type declaration and a Base Class Library (BCL) value. The TdParameter.Precision property reflects the maximum number of digits for the Hour component and it must be equal to or less than the target SQL Engine object (i.e. Column, Expression, Stored Procedure Parameters and etc.) declaration. The range of values are from One to Four.

Note
The Data Provider will throw an exception if the TotalHours property of the System.TimeSpan value is greater than 9,999 Hours. The Data Provider will throw an exception if the TotalHours property of the System.TimeSpan value is greater than the range specified by TdParameter.Precision property.

Note
The Data Provider truncates the Minutes, Seconds and Milliseconds components of the System.TimeSpan vlaue.

C#	Copy Code
TdParameter deliveryInterval = new TdParameter(); deliveryInterval.ParameterName = "deliveryHours"; deliveryInterval.DbType = DbType.Object; // Maximum number of digits for Hours deliveryInterval.Precision = 2; deliveryInterval.Value = new System.TimeSpan(0, 78, 0, 0);

Copy Code

TdParameter deliveryInterval = new TdParameter();
deliveryInterval.ParameterName = "deliveryHours";

deliveryInterval.DbType = DbType.Object;

// Maximum number of digits for Hours
deliveryInterval.Precision = 2;

deliveryInterval.Value = new System.TimeSpan(0, 78, 0, 0);

The following example shows how to configure an Interval Hour parameter using TdType type declaration and a Provider Specific value. it is recommend to always set TdParameter.Precision property, however the Data Provider will utilize TdIntervalHour.Precision property value when the TdParameter.Precision property is set to zero. .NET Applications can retrieve metadata from the Schema Collections or the Schema Table and apply the metadata to the TdParameter object.

Note
The Data Provider will throw an exception if the Interval Value is greater than the maximum permissible value specified by the TdParameter.Precision property.

C#	Copy Code
TdParameter deliveryInterval = new TdParameter(); deliveryInterval.ParameterName = "deliveryHours"; deliveryInterval.TdType = TdType.IntervalHour; // Maximum number of digits for Hours component deliveryInterval.Precision = 2; deliveryInterval.ProviderSpecificValue = new TdIntervalHour(78);

Copy Code

TdParameter deliveryInterval = new TdParameter();
deliveryInterval.ParameterName = "deliveryHours";

deliveryInterval.TdType = TdType.IntervalHour;

// Maximum number of digits for Hours component
deliveryInterval.Precision = 2;

deliveryInterval.ProviderSpecificValue = new TdIntervalHour(78);

Specifying Interval Hour as Literal

The syntax for the Interval Hour Literal is INTERVALsign'dddd'HOUR. Interval Hour literals consist of the word Interval followed by optional negative sign, character string literal representation of the number of Hours (up to 4 digits) and the word HOUR.

Note
We recommend to always use Parameters in order to take advantage of the SQL Engine's Request Cache.

The following example shows 10 Hour represented as Interval Hour Literal in the Command Text.

C#	Copy Code
using (TdConnection cn = new TdConnection("data source=x;UserId=y;Password=z;")) { cn.Open(); TdCommand cmd = cn.CreateCommand(); // Delivery exceeding 10 hours. cmd.CommandText = "SELECT Id, orderTS from Order where (CURRENT_DATE - OrderTS) > INTERVAL'10'HOUR "; using (TdDataReader reader = cmd.ExecuteReader()) { if (reader.HasRows) { while (reader.Read()) { Console.WriteLine("Id={0}", reader.GetInt64(0).ToString()); } } } }

Copy Code

using (TdConnection cn = new TdConnection("data source=x;UserId=y;Password=z;"))
{
    cn.Open();
    TdCommand cmd = cn.CreateCommand();

    // Delivery exceeding 10 hours.
    cmd.CommandText = "SELECT Id, orderTS from Order where (CURRENT_DATE - OrderTS) > INTERVAL'10'HOUR ";

    using (TdDataReader reader = cmd.ExecuteReader())
    {
        if (reader.HasRows)
        {
            while (reader.Read())
            {
                Console.WriteLine("Id={0}", reader.GetInt64(0).ToString());
            }
        }
    }
}

Retrieving Interval Hour Data

The following methods and properties return the column or parameter value as a System.TimeSpan structure.

The following methods and properties return the column or parameter value as a TdIntervalHour structure.

C#	Copy Code
using (TdConnection cn = new TdConnection("data source=DS1;UserId=Joe;Password=XY;")) { cn.Open(); TdCommand cmd = cn.CreateCommand(); cmd.CommandText = "SELECT Id, orderTS, deliveryHours from Order where deliveryHours > ?"; cmd.Parameters.Add("deliveryHours", TdType.IntervalHour); cmd.Parameters[0].Precison = 2; cmd.Parameters[0].Value = new TimeSpan(0, 10, 0, 0); using (TdDataReader reader = cmd.ExecuteReader()) { if (reader.HasRows) { while (reader.Read()) { Console.WriteLine("[TimeSpan] Delivery Hours = {0}", reader.GetValue(2).ToString()); Console.WriteLine("[TdIntervalHour] Delivery Hours = {0}", reader.GetTdIntervalHour(2).ToString()); } } } } /* Output: [TimeSpan] Delivery Hours = 12:00:00.0000000 [TdIntervalHour] Delivery Hours = 12 */

Copy Code

using (TdConnection cn = new TdConnection("data source=DS1;UserId=Joe;Password=XY;"))
{
    cn.Open();

    TdCommand cmd = cn.CreateCommand();
    cmd.CommandText = "SELECT Id, orderTS, deliveryHours from Order where deliveryHours > ?";
    cmd.Parameters.Add("deliveryHours", TdType.IntervalHour);
    cmd.Parameters[0].Precison = 2;
    cmd.Parameters[0].Value = new TimeSpan(0, 10, 0, 0);

    using (TdDataReader reader = cmd.ExecuteReader())
    {
        if (reader.HasRows)
        {
            while (reader.Read())
            {
                Console.WriteLine("[TimeSpan] Delivery Hours = {0}", reader.GetValue(2).ToString());
                Console.WriteLine("[TdIntervalHour] Delivery Hours  = {0}", reader.GetTdIntervalHour(2).ToString());
            }
        }
    }
}

/* Output:
    [TimeSpan] Delivery Hours  = 12:00:00.0000000
    [TdIntervalHour] Delivery Hours =  12
*/

Schema Collections

Schema Table

Configuring Parameters

Specifying Interval Hour as Literal

Retrieving Interval Hour Data

See Also