ASELECT text_id,LENGTH(text_content) - LENGTH(REPLACE(text_content,'*','')) AS num
FROM textTable;
BSELECT text_id,LENGTH(text_content) - LENGTH(REPLACE(text_content,'@','')) AS num
FROM textTable;
CSELECT text_id,LENGTH(REPLACE(text_content,'*','')) AS num
FROM textTable;
DSELECT text_id, LENGTH('*') AS num
FROM textTable;