SELECT college, region, seed FROM tournament ORDER BY region, seed; SELECT college, region AS r, seed AS s FROM tournament ORDER BY r, s; SELECT college, region, seed FROM tournament ORDER BY 2, 3;
--要以相反的順序進(jìn)行分類，應(yīng)把DESC（降序）關(guān)鍵字添加到ORDER BY子句中的列名稱中。默認(rèn)值為升序；該值可以使用ASC關(guān)鍵詞明確地指定。 SELECT a, COUNT(b) FROM test_table ORDER BY a DESC；
GROUP BY查詢
復(fù)制代碼 代碼如下:
SELECT a, COUNT(b) FROM test_table GROUP BY a DESC； SELECT COUNT(col1) AS col2 FROM t GROUP BY col2 HAVING col2 = 2;
-- HAVING不能用于應(yīng)被用于WHERE子句的條目,不能編寫如下語句： SELECT col_name FROM tbl_name HAVING col_name > 0; --而應(yīng)該這么編寫 SELECT col_name FROM tbl_name WHERE col_name > 0;
--HAVING子句可以引用總計函數(shù)，而WHERE子句不能引用： SELECT user, MAX(salary) FROM users GROUP BY user HAVING MAX(salary)>10;
LIMIT查詢
復(fù)制代碼 代碼如下:
SELECT * FROM tbl LIMIT 10; # Retrieve rows 0-9; SELECT * FROM tbl LIMIT 5,10; # Retrieve rows 6-15;
--如果要恢復(fù)從某個偏移量到結(jié)果集合的末端之間的所有的行，您可以對第二個參數(shù)是使用比較大的數(shù)。 --以下語句可以恢復(fù)從第96行到最后的所有行： SELECT * FROM tbl LIMIT 95,18446744073709551615;
