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标题：SQL常用命令使用方法
<p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">SQL常用命令使用方法--黑客必备基础知识</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">1) 数据记录筛选：</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="select * from 数据表 where 字段名=字段值 order by 字段名 [desc]"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="select * from 数据表 where 字段名 like %字段值% order by 字段名 [desc]"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="select top 10 * from 数据表 where 字段名 order by 字段名 [desc]"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="select * from 数据表 where 字段名 in ( 值1 , 值2 , 值3 )"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="select * from 数据表 where 字段名 between 值1 and 值2"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">(2) 更新数据记录：</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="update 数据表 set 字段名=字段值 where 条件表达式"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="update 数据表 set 字段1=值1,字段2=值2 …… 字段n=值n where 条件表达式"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">(3) 删除数据记录：</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="delete from 数据表 where 条件表达式"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="delete from 数据表" (将数据表所有记录删除)</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">(4) 添加数据记录：</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="insert into 数据表 (字段1,字段2,字段3 …) valuess (值1,值2,值3 …)"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="insert into 目标数据表 select * from 源数据表" (把源数据表的记录添加到目标数据表)</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">(5) 数据记录统计函数：</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">AVG(字段名) 得出一个表格栏平均值</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">COUNT(*|字段名) 对数据行数的统计或对某一栏有值的数据行数统计</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">MAX(字段名) 取得一个表格栏最大的值</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">MIN(字段名) 取得一个表格栏最小的值</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">SUM(字段名) 把数据栏的值相加</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">引用以上函数的方法：</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">sql="select sum(字段名) as 别名 from 数据表 where 条件表达式"</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">set rs=conn.excute(sql)</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">用 rs("别名") 获取统的计值，其它函数运用同上。</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">(5) 数据表的建立和删除：</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">create TABLE 数据表名称(字段1 类型1(长度),字段2 类型2(长度) …… )</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">例：create TABLE tab01(name varchar(50),datetime default now())</p><p class="p-txt" style="margin: 20px 40px; padding: 0px; font-size: 18px; line-height: 1.4; font-family: 微软雅黑, "Hiragino Sans GB", arial, helvetica, clean;">(6)asp常用的sql注入命令</p>
