Delete SQLite Row with where clause with multiple clauses

I have a feeling that KEY_DATE, KEY_GRADE, etc are you Java variable names not your actual column names. Try changing your code to this:

.delete(DATABASE_TABLE,        KEY_DATE + "='date' AND " + KEY_GRADE + "='style2' AND " +        KEY_STYLE + "='style' AND " + KEY_PUMPLEVEL + "='pumpLevel'",        null);

Also I assume that 'date', 'style', etc are stored in local variables, you should use the whereArgs parameter to project yourself from SQL Injection Attacks:

.delete(DATABASE_TABLE,        KEY_DATE + "=? AND " + KEY_GRADE + "=? AND " +        KEY_STYLE + "=? AND " + KEY_PUMPLEVEL + "=?",        new String[] {date, grade, style, pumpLevel});

(where date = "date", grade = "style2", etc)

Added from comments

To delete the last row use this:

.delete(DATABASE_TABLE,        "ROWID = (SELECT Max(ROWID) FROM " + DATABASE_TABLE + ")",        null);

To delete your last matching row try this:

.delete(DATABASE_TABLE,        "ROWID = (SELECT Max(ROWID) FROM " + DATABASE_TABLE + " WHERE " +            "KEY_DATE='date' AND KEY_GRADE='style2' AND " +            "KEY_STYLE='style' AND KEY_PUMPLEVEL='pumpLevel')",        null);

But see my second note about SQL Injection Attacks to protect your data.

You should use:

Database.delete(DATABASE_TABLE,                "KEY_DATE=? AND KEY_GRADE = ? AND KEY_STYLE = ? AND KEY_PUMPLEVEL = ?",                 new String[]{"date", "style2", "style", "pumpLevel"});

which simplifies escaping values.