插入语句：

        INSERT INTO table1 VALUES (value1, value2, valueAll);

        INSERT INTO table1(field1, field2) VALUES (value1, value2);

更新语句：

        UPDATEtable1 SET field1='value1', field2='value2' WHERE field3='value3';

删除语句：

        DELETEFROM table1 WHERE field1='value1';

SELECT 语句：SELECT DISTINCT field1, field2 FROM table1;

            DISTINCT --值不重复

            SELECT * FROM table1 WHERE field1='value';

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left join  on