SQL 查詢

SQL 查詢

SQL SELECT

SELECT column1, column2, ... FROM table_name; * 代表全部列名 [推薦] 分別列出查詢列名

SQL DISTINCT[去重復]

SELECT DISTINCT column1, column2, ... FROM table_name; [注意]僅返回不同的數(shù)據(jù)行，相同行數(shù)據(jù)只顯示一行

SQL WHERE[帶子句]

SELECT column1, column2, ... FROM table_name WHERE condition; [子句]

= 等于

<> 不等于 [!=]

\> 大于

< 小于

\>= 大于等于

<=小于等于

BETWEEN范圍

LIKE 相似

IN ()內(nèi)容

SQL AND & OR [運算符]

SELECT column1, column2, ... FROM table_name WHERE condition1 AND condition2 OR condition3 NOT condition4 ...; [運算符]為真 執(zhí)行返回，為假 執(zhí)行跳過忽略

SQL ORDER BY[按關(guān)鍵字排序]

SELECT column1, column2, ... FROM table_name ORDER BY column1, column2, ... ASC|DESC; [備注] ORDER BY 關(guān)鍵字用于按升序或降序?qū)Y(jié)果集進行排序。 ORDER BY 關(guān)鍵字默認情況下按升序排序記錄。