1.查詢整個表中所有語句:select *from tablename
2.查詢某一列或幾列: select column1,column2... from tablename
3.去重:SELECT DISTINCT column_name,column_name
FROM table_name;
4.排序order by : (默認升序)
SELECT column_name,column_name
FROM table_name
ORDER BY column_name,column_name ASC|DESC;
5.limit,限制查詢顯示的數量
select column1... from tablename limit number
6.LIKE &通配符 (通配符與LIKE通常一塊使用)
- LIKE : select column1,column2... from tablename where colonum like pattern
- 通配符:
7.IN in允許在where中存在多個選項
select column1,column2... from tablename where colonumin (name1,name2...)
8.between...and...,用於選擇兩個數之間的值(閉區間)
select column1,column2... from tablename where colonumbetween value1and
value2;
9.多表查詢之連接
- 內連接(INNER JOIN或JOIN): select a.column1..., b.column1... from tablename1 a join tablename2 b on a.column=b.column
- 左連接(left join):select a.column1..., b.column1... from tablename1 a left join tablename2 b on a.column=b.column
- 右連接(right join):select a.column1..., b.column1... from tablename1 a right join tablename2 b on a.column=b.column