dotConnect for Google BigQuery supports Entity Framework Core 3, 8, 9, 10, and 11.

BigQuery to .NET Type Mapping

The following table shows the type mappings used when you generate a model from an existing dataset by running Scaffold-DbContext in Package Manager Console or dotnet ef dbcontext scaffold in the .NET CLI.

BigQuery Data Type	Store Type in the Model	.NET
INT64 (INT, SMALLINT, INTEGER, BIGINT, TINYINT, BYTEINT)	INT64	System.Int64
FLOAT64	FLOAT64	System.Double
NUMERIC (DECIMAL)	NUMERIC, NUMERIC(p, s)	System.Decimal
BIGNUMERIC (BIGDECIMAL)	BIGNUMERIC, BIGNUMERIC(p, s)	System.Decimal
BOOL	BOOL	System.Boolean
STRING	STRING, STRING(n)	System.String
BYTES	BYTES, BYTES(n)	System.Byte[]
DATE	DATE	System.DateTime
TIME	TIME	System.TimeSpan
DATETIME	DATETIME	System.DateTime
TIMESTAMP	TIMESTAMP	System.DateTimeOffset
JSON	JSON	System.String
GEOGRAPHY	GEOGRAPHY	System.String
INTERVAL	INTERVAL	System.String
RANGE<DATE | DATETIME | TIMESTAMP>	RANGE<DATE>, RANGE<DATETIME>, RANGE<TIMESTAMP>	System.String

.NET to BigQuery Type Mapping

The following table shows the type mappings used when you create a database from a model through Code First, migrations, or EnsureCreated, and when you use parameters and literals in queries.

.NET	BigQuery Data Type
System.Int64, System.Int32, System.Int16, System.Byte, System.SByte	INT64
System.Double, System.Single	FLOAT64
System.Decimal	NUMERIC; NUMERIC(p, s) if precision and scale are specified
System.Boolean	BOOL
System.String	STRING; STRING(n) if the maximum length is specified
System.Byte[]	BYTES
System.Guid	STRING (the value is stored as text)
System.DateTime	DATETIME
System.DateTimeOffset	TIMESTAMP
System.TimeSpan	TIME
System.DateOnly1	DATE
System.TimeOnly1	TIME

¹ Entity Framework Core 8 and later.

Notes

• INT, SMALLINT, INTEGER, BIGINT, TINYINT, and BYTEINT are aliases of INT64 in BigQuery. The declared alias isn't stored in the table schema, so such columns are always scaffolded as System.Int64. You can change the property type to System.Int32 or System.Int16 manually if the values fit into the range of that type.
• You can map a property to another compatible type with the HasColumnType method or the Column attribute. For example, map System.DateTime to DATE or TIMESTAMP, System.Decimal to BIGNUMERIC, or System.String to JSON, GEOGRAPHY, INTERVAL, or RANGE<...>.
• NUMERIC supports precision up to 38 and scale up to 9. For System.Decimal properties with a greater precision or scale, specify the BIGNUMERIC(p, s) type explicitly with the HasColumnType method.
• BIGNUMERIC values that don't fit into the range of System.Decimal (28 - 29 significant digits) can't be read.
• BigQuery doesn't enforce primary keys and doesn't support foreign keys and indexes. Primary keys are created as PRIMARY KEY ... NOT ENFORCED; foreign keys and indexes defined in the model aren't created in the database.
• BigQuery never generates values, so key values must be assigned by the application.