I am trying to write a BigQuery script that I can store as a procedure, I would like one of the arguments I pass to be used in the table name that is written out by the script, for example:
DECLARE id STRING;
SET id = '123';
CREATE OR REPLACE TABLE test.id AS(
SELECT * FROM dataset.table
)
However, in this example the table is created with the name id rather than the value of the "id" variable, 123. Is there any way I can dynamically create a table using the value of a declared variable in the BigQuery UI?
Why not just use Execute Immediate with concat if you know the table schema?
EXECUTE IMMEDIATE CONCAT('CREATE TABLE `', id, '` (column_name STRING)');
So far we have officially announced BigQuery scripting document, which is still in Beta phase, leveraging usage of dynamic parameters (variables) as a placeholders for values in SQL queries . However, according to Parameterized queries in BigQuery documentation, query parameters can't be used for SQL object identifiers:
Parameters cannot be used as substitutes for identifiers, column
names, table names, or other parts of the query.
Maybe you can use a wildcard table. You would create a wildcard table with all subtables you want to query and use the WHERE clause to select any subtable you want. Just be careful, the tables must have the same schema.
Related
I have a look-up table containing a list of fully qualified table paths in a Big Query table called all_tables. For example
|table_list|
|----------|
|project_name.dataset_name1.table_1|
|project_name.dataset_name2.table_1|
|project_name.dataset_name3.table_1|
|project_name.dataset_name4.table_1|
|project_name.dataset_name5.table_1|
I am trying to iterate through these tables to pull out elements I need for another procedure using the for-in syntax in Big Query. This is a simplified version of the query I am using
```
FOR table IN (select * from my_project.my_dataset.all_tables)
DO
select * from table;
END FOR;
```
This isn't working. It picks up the list of tables correctly, but when it substitutes the dataset name in the line 3 select statement, it says
**Invalid value: Table "table" must be qualified with a dataset (e.g. dataset.table)**
I know what the error is, but I am not sure how to make it 'see' the value of table as a table path.
All paths are correct, and I am doing it this way as I am querying multiple tables across multiple datasets for a table creation query.
You should a dynamic sql to refer the table name as a variable, so consider below query:
FOR table IN (select * from my_project.my_dataset.all_tables)
DO
EXECUTE IMMEDIATE FORMAT("""
SELECT * FROM %s;
""", table.table_list);
END FOR;
I am trying to write a BigQuery script that I can store as a procedure, I would like one of the arguments I pass to be used in the table name that is written out by the script, for example:
DECLARE id STRING;
SET id = '123';
CREATE OR REPLACE TABLE test.id AS(
SELECT * FROM dataset.table
)
However, in this example the table is created with the name id rather than the value of the "id" variable, 123. Is there any way I can dynamically create a table using the value of a declared variable in the BigQuery UI?
Why not just use Execute Immediate with concat if you know the table schema?
EXECUTE IMMEDIATE CONCAT('CREATE TABLE `', id, '` (column_name STRING)');
So far we have officially announced BigQuery scripting document, which is still in Beta phase, leveraging usage of dynamic parameters (variables) as a placeholders for values in SQL queries . However, according to Parameterized queries in BigQuery documentation, query parameters can't be used for SQL object identifiers:
Parameters cannot be used as substitutes for identifiers, column
names, table names, or other parts of the query.
Maybe you can use a wildcard table. You would create a wildcard table with all subtables you want to query and use the WHERE clause to select any subtable you want. Just be careful, the tables must have the same schema.
I am trying to search for information on this topic in sql but search is not showing me results.
SELECT * FROM TABLE(package/procedure/function);
Which topic does the above sql statement come under? Can I have a link to a doc?
The TABLE collection expression is described here in the Oracle documentation.
In short, it is used to convert a collection or pipelined function into a table that can be queried by a SELECT statement.
Typically, the collection must be of a datatype that is defined at the database level (i.e. a datatype that was created by a create or replace type ... statement).
e.g.
select *
from table(sample_pkg.func_that_rtrns_array);
I have a form where people can type in a start and end date, as well as a column name prefix.
In the backend, I want to do something along the lines of
SELECT *, CAST('{{startDate}}' AS TIMESTAMP) AS ({{prefix}} + '_startDate')
Is this possible? Basically, I want to dynamically create the name of the new column. The table is immediately returned to the user, so I don't want to mutate the underlying table itself. Thanks!
You can execute dynamic query that you have prepared by using EXECUTE keyword, otherwise it is not possible to have dynamic structure of SQL.
Since you are preparing your SQL outside database, you can use something like:
SELECT *, CAST('{{startDate}}' AS TIMESTAMP) AS {{prefix}}_startDate
Assuming that {{prefix}} is replaced with some string by your template before it is sent to database.
INFORMIX-SQL or any other SQL-based DB:
Suppose I have an app where depending on the value of some columns, example:
company.code char(3) {abc}
company.branch char(2) {01}
Can I construct table name "abc01" for inclusion in SELECT * FROM abc01; ?
In other words, a variable table name.. same question applies for column names.
Only in a language which can manipulate character strings and handle Dynamic SQL. It has to create the statement on the fly.
You can only use placeholders in queries for values, not for the structural elements of the query such as the table name or column name.
Only if you use dynamic sql. It's like you build sql code in your app, then use something like execute immediate.
sprintf(cdb_text1, "create table %s (field1 char(3));", usr_db_id);
EXEC SQL execute immediate :cdb_text;
If you use dynamic sql, it's bad because of sql injections.