Introduction

Home Comparison

Converting Objects

Table View Stored Procedure Datatypes

Converting SQL

SELECT Statement INSERT Statement UPDATE Statement MERGE Statement DELETE Statement Column Alias QUALIFY Clause

Home » Guides

Bookmark · Report · More actions.. Lock comments · Pin thread

Convert SELECT statements from Teradata to BigQuery - Migration Guide

Here are the comparison between Teradata & BigQuery SQL SELECT versions:

Teradata	BigQuery	Comments
SELECT c FROM database.table	SELECT c FROM project.dataset.table	Columns implicitly inferred from the table are supported
SELECT table.c FROM database.table	SELECT table.c FROM project.dataset.table	Using an explicit table reference is supported
SELECT t.c FROM database.table t	SELECT t.c FROM project.dataset.table t	Using an explicit table alias is supported
SELECT t.c,count(1) FROM database.table t group by 1	SELECT t.c,count(1) FROM database.table t group by 1	Using positional references in the group by clause is supported
SELECT (subquery) AS flag, CASE WHEN flag = 1 THEN ...	WITH flags AS ( subquery ), SELECT CASE WHEN flags.flag = 1 THEN ...	In BigQuery, columns cannot reference the output of other columns defined within the same select list. Prefer moving a subquery into a WITH clause
SELECT TOP 10 * FROM table	SELECT * FROM table LIMIT 10

Joins in Teradata vs BigQuery

Teradata	BigQuery
FROM A, B ON A.id = B.id	FROM A JOIN B ON A.id = B.id

Using a comma between tables in Teradata is equal to an INNER JOIN, while in BigQuery it equals a CROSS JOIN (Cartesian product)

◀ Previous Tutorial

Next Tutorial ▶

INSERT Statement

Post Comment