Summary
Data collection and processing can lead to imperfections, making it crucial to check for irregularities before analysis. Cleaning the data is a significant step, especially for string columns in engines like BigQuery. Functions such as TRIM/RTRIM/LTRIM, REPLACE, UPPER/LOWER/NORMALIZE, and SUBSTR/SUBSTRING help process strings, remove whitespace, replace substrings, control casing, and cut strings. The objective is to standardize data, identify related observations, and detect missing data.
