How Can I Count Character Occurrences (e.g., 'Y') within SQL Columns?

Counting Character Occurrences in SQL Columns

Efficiently determining the frequency of specific characters within SQL text columns is crucial for data analysis. Let's consider a column containing only 'Y' and 'N' characters, representing boolean values. The challenge is to count the number of 'Y's in each row.

Method for Boolean ('Y'/'N') Columns

For columns exclusively containing 'Y' and 'N', a concise SQL query provides the 'Y' count:

SELECT LEN(REPLACE(col, 'N', '')) AS Y_Count
FROM your_table;

This replaces all 'N's with empty strings, leaving only 'Y's. LEN() then calculates the length, giving the 'Y' count.

Method for General String Columns

If the column contains arbitrary strings, a slightly different approach is needed to count occurrences of a specific character (e.g., 'Y'):

SELECT LEN(col) - LEN(REPLACE(col, 'Y', '')) AS Y_Count
FROM your_table;

This calculates the difference between the original string length and the length after removing all 'Y's. This difference equals the number of 'Y's. This method is more versatile and works for any character within a string.

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