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标题: COPY A SQLITE DB TABLE FROM DISK INTO MEMORY [打印本页]

作者: shiyiming    时间: 2010-10-22 13:24
标题: COPY A SQLITE DB TABLE FROM DISK INTO MEMORY
From Wensui Liu's blog

<font size="2"><font color="#0000ff">##################################################</font><br /><font color="#0000ff"># A DEMO HOW TO COPY A SQLITE DB TABLE FROM DISK #</font><br /><font color="#0000ff"># INTO MEMORY                                    #</font><br /><font color="#0000ff">##################################################</font><br /><br /><font color="#a020f0">import</font> sqlite3<br /><br /><font color="#0000ff"># CONNECT TO THE IN-MEMORY DATABASE</font><br />con = sqlite3.connect(&quot;<font color="#ff00ff">&#58;memory&#58;</font>&quot;)<br />cur = con.cursor()<br /><br /><font color="#0000ff"># ATTACH SQLITE DB IN THE DISK</font><br />cur.execute(&quot;<font color="#ff00ff">attach 'd&#58;\mydb' as filedb</font>&quot;)<br /><br /><font color="#0000ff"># COPY THE TABLE INTO IN-MEMORY DB</font><br />cur.execute(&quot;<font color="#ff00ff">create table memory_tbl as select * from filedb.mytab</font>&quot;)<br /><br /><font color="#0000ff"># RELEASE THE DB IN THE DISK</font><br />cur.execute(&quot;<font color="#ff00ff">detach filedb</font>&quot;)<br /><br /><font color="#0000ff"># FETCH ROWS FROM IN-MEMORY DB</font><br />cur.execute(&quot;<font color="#ff00ff">select Sepal_Length, Species from memory_tbl limit 3</font>&quot;)<br /><br /><font color="#804040"><b>for</b></font> row <font color="#804040"><b>in</b></font> cur.fetchall()&#58;<br />  <font color="#804040"><b>print</b></font> row<br /><br /><font color="#0000ff"># OUTPUT&#58;</font><br /><font color="#0000ff"># (5.0999999999999996, u'setosa')</font><br /><font color="#0000ff"># (4.9000000000000004, u'setosa')</font><br /><font color="#0000ff"># (4.7000000000000002, u'setosa')</font></font>




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