sqlite
資料庫;使用;內(nèi)嵌關(guān)係資料庫
having
英['h?v??]? ?美[ 'h?v??]??
n.所有,持有
v.有( have的現(xiàn)在分詞);(親屬關(guān)係中)接受;拿;買
SQLite Having函數(shù) 語法
作用:HAVING 子句允許指定條件來篩選將出現(xiàn)在最終結(jié)果中的分組結(jié)果。
WHERE 子句在所選列上設(shè)定條件,而 HAVING 子句則在 GROUP BY 子句建立的分組上設(shè)定條件。
語法:以下是HAVING 子句在SELECT 查詢中的位置:
SELECT
FROM
WHERE
GROUP?BY
HAVING
ORDER?BY
在一個查詢中,HAVING 子句必須放在GROUP BY 子句之後,必須放在ORDER BY 子句之前。以下是包含HAVING 子句的SELECT 語句的語法:
SELECT?column1,?column2
FROM?table1,?table2
WHERE?[?conditions?]##?]
ORDER?BY?column1,?column2
SQLite Having函數(shù) 範例
COMPANY 表有以下記錄: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 1 Paul 32 California 20000.0 2 Allen 25 Texas 15000.0 3 Teddy 23 Norway 20000.0 4 Mark 25 Rich-Mond 65000.0 5 David 27 Texas 85000.0 6 Kim 22 South-Hall 45000.0 7 James 24 Houston 10000.0 8 Paul 24 Houston 20000.0 9 James 44 Norway 5000.0 10 James 45 Texas 5000.0 下面是一個實例,它將顯示名稱計數(shù)小于 2 的所有記錄: sqlite > SELECT * FROM COMPANY GROUP BY name HAVING count(name) < 2; 這將產(chǎn)生以下結(jié)果: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 2 Allen 25 Texas 15000 5 David 27 Texas 85000 6 Kim 22 South-Hall 45000 4 Mark 25 Rich-Mond 65000 3 Teddy 23 Norway 20000 下面是一個實例,它將顯示名稱計數(shù)大于 2 的所有記錄: sqlite > SELECT * FROM COMPANY GROUP BY name HAVING count(name) > 2; 這將產(chǎn)生以下結(jié)果: ID NAME AGE ADDRESS SALARY ---------- ---------- ---------- ---------- ---------- 10 James 45 Texas 5000