I am trying to set a variable's value as a table's name. This is the query I am using.
DECLARE var STRING;
SELECT var = (SELECT
ARRAY_AGG(table_id)[OFFSET(0)]
FROM `dx-api-project.dv360_integration.__TABLES__`);
SELECT var
The query runs all fine, without any error. But when I see var's value, it shows null. However, when I just execute the query without variable declaration and assignment, ARRAY_AGG(table_id)[OFFSET(0)]'s value comes out to be what it should be.
Can anyone help me understand the issue here? Thank you
CodePudding user response：
Use SET instead of SELECT. Valid syntax for setting a variable is :
DECLARE var STRING;
SET var = (SELECT ARRAY_AGG(table_id)[OFFSET(0)]
FROM `dx-api-project.dv360_integration.__TABLES__`);
or initialize a variable with a default value,
DECLARE var STRING DEFAULT (
SELECT ARRAY_AGG(table_id)[OFFSET(0)]
FROM `dx-api-project.dv360_integration.__TABLES__`
);