ADO.NET Supported Types and Their Mappings

The following lists the built-in mappings for reading and writing CLR types to YDB types.

Type Mapping Table for Reading

The following shows the mappings used when reading values.

• These are the return types when using YdbCommand.ExecuteScalarAsync(), YdbDataReader.GetValue(), and similar methods.
• You can read as other types by calling YdbDataReader.GetFieldValue<T>() and also YdbDataReader.GetInt32() / YdbDataReader.GetInt64() to get the raw value.

Decimal

Decimal (Precision, Scale) is a parameterized data type in YDB that allows you to explicitly specify:

• Precision — the total number of significant digits;
• Scale — the number of digits after the decimal point.

For more details, see the documentation.

By default, the Decimal(22, 9) type is used. If you need to set different values for Precision and Scale, you can do this in your code.

The example below demonstrates how to store the value 1.5 in the database with the Decimal type and parameters Precision = 5 and Scale = 3.

await new YdbCommand(ydbConnection)
{
    CommandText = $"INSERT INTO {tableName}(Id, Decimal) VALUES (1, @Decimal);",
    Parameters = new YdbParameter { Name = "Decimal", Value = 1.5m, Precision = 5, Scale = 3 }
}.ExecuteNonQueryAsync();

Type Mapping Table for Writing

There are three rules that determine the YDB type sent for a parameter:

1. If the parameter's YdbDbType is set, it is used.
2. If the parameter's DbType is set, it is used.
3. If none of the above is set, the backend type will be inferred from the CLR value type.