Query with CAST unix TIMESTAMP as datetime (Native SQL)

Native SQL — the SQL runs on the BigQuery side (server-side). Prefix with #DirectSQL to use this mode. Shows how to return a timestamp column as date or datetime using CAST(col_timestamp AS DATE) or CAST(col_timestamp AS DATETIME).

Standard SQL query example

This is the base query accepted by the connector. To execute it in SQL Server, you have to pass it to the Data Gateway via a Linked Server. See how to accomplish this using the examples below.

#DirectSQL 
SELECT id, col_timestamp, CAST(col_timestamp AS DATE) AS timestamp_as_date, CAST(col_timestamp AS DATETIME) AS timestamp_as_datetime
FROM MyProject.MyDataset.MyTable
LIMIT 10

Using OPENQUERY in SQL Server

SELECT * FROM OPENQUERY([LS_TO_GOOGLE_BIGQUERY_IN_GATEWAY], '#DirectSQL 
SELECT id, col_timestamp, CAST(col_timestamp AS DATE) AS timestamp_as_date, CAST(col_timestamp AS DATETIME) AS timestamp_as_datetime
FROM MyProject.MyDataset.MyTable
LIMIT 10')

Using EXEC in SQL Server (handling larger SQL text)

The major drawback of OPENQUERY is its inability to incorporate variables within SQL statements. This often leads to the use of cumbersome dynamic SQL (with numerous ticks and escape characters).

Fortunately, starting with SQL 2005 and onwards, you can utilize the EXEC (your_sql) AT [LS_TO_GOOGLE_BIGQUERY_IN_GATEWAY] syntax.

DECLARE @MyQuery NVARCHAR(MAX) = '#DirectSQL 
SELECT id, col_timestamp, CAST(col_timestamp AS DATE) AS timestamp_as_date, CAST(col_timestamp AS DATETIME) AS timestamp_as_datetime
FROM MyProject.MyDataset.MyTable
LIMIT 10'
EXEC (@MyQuery) AT [LS_TO_GOOGLE_BIGQUERY_IN_GATEWAY]