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POremove additional rows with mysql
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  1. POremove additional rows with mysql
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    copied!<p>I have a database that contains the tables.</p> <pre><code>create table student ( stu_code integer, stu_name varchar(32), primary key (stu_code) ) create table teacher ( tea_code integer not null, tea_name varchar(25), primary key (tea_code) ) create table course ( cor_code integer not null, cor_name varchar(32), salary float(32), unit integer, primary key (cor_code) ) create table term ( stu_code integer, cor_code integer, tea_code integer, grade decimal(25), year integer, ) </code></pre> <p>I've filled three tables manually.</p> <p>And term Table was generated by a Javascript code : </p> <pre><code>&lt;html&gt; &lt;body&gt; &lt;div id="rnd"&gt;&lt;/div&gt; &lt;script type="text/javascript"&gt; function rnd(a,b){ return Math.floor(Math.random()*(b-a+1))+a; } for (var i=0;i&lt;600;i++) { var stu = rnd(41,49), cor = rnd(10,26), tea = rnd(81,90), year = rnd(1391,1392), grade = rnd(8,20); (year==1392)?grade = null:true; document.writeln( "insert into term (stu_code,cor_code,tea_code,grade,year) values " +"(884221" +stu+"," +"180" +cor+"," +"15120" +tea+"," +grade +"," +year +");" +"&lt;br&gt;" ); } &lt;/script&gt; &lt;/body&gt; &lt;/html&gt; </code></pre> <p>My problem is there are additional rows in term Table.</p> <p>How do I integrate/remove additional rows ?</p> <p>Is there a way to fill the table with no additional random row?</p> <p><strong>/* update : */</strong></p> <p>for example : </p> <pre><code>insert into term (s,c,t,g) values (45,16,88,16,91); insert into term (s,c,t,g) values (45,16,86,10,91); insert into term (s,c,t,g) values (45,16,87,8,91); insert into term (s,c,t,g) values (41,15,85,20,91); insert into term (s,c,t,g) values (41,15,88,17,91); </code></pre> <p>now i want to display : </p> <pre><code>insert into term (s,c,t,g) values (45,16,88,16,91); insert into term (s,c,t,g) values (41,15,85,20,91); or insert into term (s,c,t,g) values (45,16,88,16,91); insert into term (s,c,t,g) values (41,15,88,17,91); or insert into term (s,c,t,g) values (45,16,86,10,91); insert into term (s,c,t,g) values (41,15,85,20,91); or insert into term (s,c,t,g) values (45,16,86,10,91); insert into term (s,c,t,g) values (41,15,88,17,91); or insert into term (s,c,t,g) values (45,16,87,8,91); insert into term (s,c,t,g) values (41,15,85,20,91); or insert into term (s,c,t,g) values (45,16,87,8,91); insert into term (s,c,t,g) values (41,15,88,17,91); </code></pre> <p><strong>/*end update */</strong></p> <p><strong>/* update again */</strong></p> <p>I could write a code in Sql Server But this code does not work in Mysql why? What is the equivalent of this code in Mysql?</p> <pre><code>delete from term where stu_code in( select stu_code from term group by stu_code,cod_code,year having COUNT(stu_code)&gt;=2 </code></pre> <p><strong>/* end last update */</strong></p> <p>please help me to solve this !</p> <p>thanks :x</p>
 

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