parse date form string in bigquery

Question

I have a table in bigquery that has a column name \"timeStamp\" with data type of STRING. The value in this column looks like this \"20180902\".

This is how I am trying

Answer 1

Below example shows that if value is really "20180902" as you state it should work

#standardSQL
WITH `project.dataset.table` AS (
  SELECT '20180902' timeStamp   
)
SELECT 
  `timeStamp`, 
  PARSE_DATE('%Y%m%d', timeStamp    ) AS date    
FROM `project.dataset.table`

with result as

Row   timeStamp   date   
1     20180902    2018-09-02     

so the issue potentially in some wrong value in some rows - and you need to identify these row(s)

Answer 2

I found the issue. My table had a row at the bottom that had the value "timeStamp" . Deleted that row and everything worked .