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Convert String List to Average
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Convert String List to Average

MediumSQL · PostgreSQL

Problem

You have a column in a data frame that contains strings like [1,2,3,4,5]; convert it into an average integer value.

Write a SQL query that reads the string, extracts the numbers inside the brackets, and returns the average as an integer for each row.

Output

  1. One row per non-empty input row
  2. Columns: row_id, average_value
  3. Ignore rows where the string is NULL, empty, or contains no valid numbers
  4. Return results ordered by row_id

Schema

sample_arrays
ColumnTypeDescription
row_idPKINTUnique row identifier
array_stringVARCHAR(100)String containing bracketed comma-separated integers
Tablessample_arrays
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