I use this query
SELECT * FROM `project.DATASET.*`
to select all the data in DATASET,
There is a way to add a new column to identify which table belong each record?
You're using a wildcard query, which support a special _TABLE_SUFFIX identifier. Most use it for filtering the set of matched tables, but you can project it as a result column as well.
More info here: https://cloud.google.com/bigquery/docs/querying-wildcard-tables
Something like this:
SELECT
_TABLE_SUFFIX as src_tbl,
*
FROM `project.dataset.*`
Related
I have a scheduled query set up, but I want to select FROM my_project.my_database.my_table_{todays_date} each day.
I found how to create variables in BigQuery like:
DECLARE todays_date STRING DEFAULT REPLACE(CAST(CURRENT_DATE AS STRING), '-', '').
(Date Format: YYYYMMDD (no underscore or hyphen))
But how could I query from this table each day?
`my_project.my_database.my_table_{todays_date}`
You can achieve this using queries with wildcards in the table name. The documentation here explains it very well:
https://cloud.google.com/bigquery/docs/querying-wildcard-tables
Additionally in your case if you wanted to filter against a subset of the tables you could do something like this where the _TABLE_SUFFIX psuedo column is used to filter to select tables based on the #run_date variable if being done through a scheduled query:
SELECT *
FROM my_project.my_dataset.my_table_*
WHERE _TABLE_SUFFIX = CAST(#run_date AS STRING)
I need dynamically obtain table name from system table and perform a select query on this table example:
SELECT "schema"+'.'+"table" FROM SVV_TABLE_INFO WHERE "table" LIKE '%blabla%'
it returns my_schema.the_main_blabla_table
And after I get this table name I need to perform :
SELECT * FROM my_schema.the_main_blabla_table LIMIT 100
Is it possible to in a single query?
If you are talking about select subquery after "from" i can say that you can do this.
You will get something like this:
SELECT * FROM
(
SELECT "schema"+'.'+"table" FROM SVV_TABLE_INFO WHERE "table" LIKE '%blabla%'
)
LIMIT 100
Unfortunately, i can't test it on yor data, but i very interested in result because i have never done something like this. If i get your question incorrect, tell me pls.
Amazon Redshift does not support the ability to take the output of a query and use it as part of another query.
Your application will need to query Redshift to obtain the relevant table name(s), then make another call to Redshift to query that table.
I am a newbie in Oracle SQL, though I have experience in SQL Server.
In SQL Server, to select the rows from a table with a particular column in front:
select columnName,* from tableName
In Oracle:
select columnName,* from tableName
gives error ORA-00936: missing expression, as below:
Please guide.
I can't view images, but here's what I think you need:
select t.column_name, t.*
from table_name t
i.e. you should prefix that particular column name with a table alias ("t"), and then use the same alias with the asterisk ("t.*") to retrieve all table columns.
In Oracle, if you need to view a column but also all columns, you need to define an alias for the table.
Select columnName, A.*
from tableName A;
few things we need to keep it in mind
Alias name in sql - used to derive the individual column name via select query
When you are going to use *[select all] you don't have to worry about the alias name
But when you try to pull all the columns and some specific fields you want to filter then you should go for "Alias"
Alias its object key to refer the inter column
select stu.studentName,stu.* from student stu;
I want tow write a Teradata SQL query.
I have two attributes: date and name.
I want to create do a comparison for those two only using ONE subquery. I want it to look something like:
date,name= SELECT date, name FROM ...
Is it possible? How does that syntax look like
Have you tried the following:
SELECT {columns}
FROM {TableA}
WHERE (date,name) IN (SELECT date, name FROM {TableB});
I have datasets of the same structure and i know I can query them like this, they are named by date:
SELECT column
FROM [xx.ga_sessions_20141019] ,[xx.ga_sessions_20141020],[xx.ga_sessions_20141021]
WHERE column = 'condition';
However I actually want to query various months of this data... so instead of listing them all in the same way as above, is there syntax that you can use that looks like:
SELECT column
FROM [xx.ga_sessions_201410*] ,[xx.ga_sessions_201411*]
WHERE column = 'condition';
Take a look at the table wildcard functions section of the BigQuery query reference. TABLE_DATE_RANGE or TABLE_QUERY will work for you here. Something like:
SELECT column
FROM TABLE_DATE_RANGE(xx.ga_sessions_,
TIMESTAMP('2014-10-19'),
TIMESTAMP('2014-10-21'))
WHERE column = 'condition';