vpruthi/doc-exports
1
0
Fork 0
forked from docs/doc-exports
Code Pull Requests Activity
doc-exports/docs/dws/dev/dws_04_0101.html
Lu, Huayi e6fa411af0 DWS DEV 830.201 version 
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com>
Co-authored-by: Lu, Huayi <luhuayi@huawei.com>
Co-committed-by: Lu, Huayi <luhuayi@huawei.com>
2024-05-16 07:24:04 +00:00

184 lines
21 KiB
HTML
Raw Blame History

<a name="EN-US_TOPIC_0000001188163768"></a><a name="EN-US_TOPIC_0000001188163768"></a>
<h1 class="topictitle1">Example: Migrating Data from MySQL to <span id="text1998246280">GaussDB(DWS)</span></h1>
<div id="body1527239099917"><p id="EN-US_TOPIC_0000001188163768__a02b83f0a4e214fdb9d608a621306138c">The following example shows how to use CopyManager to migrate data from MySQL to <span id="EN-US_TOPIC_0000001188163768__text1658087719">GaussDB(DWS)</span>.</p>
<div class="codecoloring" codetype="Java" id="EN-US_TOPIC_0000001188163768__s64720293e41e4573a8039a2ff56dd019"><div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span class="normal"> 1</span>
<span class="normal"> 2</span>
<span class="normal"> 3</span>
<span class="normal"> 4</span>
<span class="normal"> 5</span>
<span class="normal"> 6</span>
<span class="normal"> 7</span>
<span class="normal"> 8</span>
<span class="normal"> 9</span>
<span class="normal">10</span>
<span class="normal">11</span>
<span class="normal">12</span>
<span class="normal">13</span>
<span class="normal">14</span>
<span class="normal">15</span>
<span class="normal">16</span>
<span class="normal">17</span>
<span class="normal">18</span>
<span class="normal">19</span>
<span class="normal">20</span>
<span class="normal">21</span>
<span class="normal">22</span>
<span class="normal">23</span>
<span class="normal">24</span>
<span class="normal">25</span>
<span class="normal">26</span>
<span class="normal">27</span>
<span class="normal">28</span>
<span class="normal">29</span>
<span class="normal">30</span>
<span class="normal">31</span>
<span class="normal">32</span>
<span class="normal">33</span>
<span class="normal">34</span>
<span class="normal">35</span>
<span class="normal">36</span>
<span class="normal">37</span>
<span class="normal">38</span>
<span class="normal">39</span>
<span class="normal">40</span>
<span class="normal">41</span>
<span class="normal">42</span>
<span class="normal">43</span>
<span class="normal">44</span>
<span class="normal">45</span>
<span class="normal">46</span>
<span class="normal">47</span>
<span class="normal">48</span>
<span class="normal">49</span>
<span class="normal">50</span>
<span class="normal">51</span>
<span class="normal">52</span>
<span class="normal">53</span>
<span class="normal">54</span>
<span class="normal">55</span>
<span class="normal">56</span>
<span class="normal">57</span>
<span class="normal">58</span>
<span class="normal">59</span>
<span class="normal">60</span>
<span class="normal">61</span>
<span class="normal">62</span>
<span class="normal">63</span>
<span class="normal">64</span>
<span class="normal">65</span>
<span class="normal">66</span>
<span class="normal">67</span>
<span class="normal">68</span>
<span class="normal">69</span>
<span class="normal">70</span>
<span class="normal">71</span>
<span class="normal">72</span>
<span class="normal">73</span>
<span class="normal">74</span>
<span class="normal">75</span>
<span class="normal">76</span>
<span class="normal">77</span>
<span class="normal">78</span>
<span class="normal">79</span>
<span class="normal">80</span>
<span class="normal">81</span>
<span class="normal">82</span>
<span class="normal">83</span>
<span class="normal">84</span>
<span class="normal">85</span></pre></div></td><td class="code"><div><pre><span></span><span class="c1">//gsjdbc4.jar is used as an example.</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">java.io.StringReader</span><span class="p">;</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">java.sql.Connection</span><span class="p">;</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">java.sql.DriverManager</span><span class="p">;</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">java.sql.ResultSet</span><span class="p">;</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">java.sql.SQLException</span><span class="p">;</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">java.sql.Statement</span><span class="p">;</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">org.postgresql.copy.CopyManager</span><span class="p">;</span>
<span class="kn">import</span><span class="w"> </span><span class="nn">org.postgresql.core.BaseConnection</span><span class="p">;</span>
<span class="kd">public</span><span class="w"> </span><span class="kd">class</span> <span class="nc">Migration</span><span class="p">{</span>
<span class="w"> </span><span class="kd">public</span><span class="w"> </span><span class="kd">static</span><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">main</span><span class="p">(</span><span class="n">String</span><span class="o">[]</span><span class="w"> </span><span class="n">args</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">url</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">String</span><span class="p">(</span><span class="s">&quot;jdbc:postgresql://10.180.155.74:8000/gaussdb&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">//URL of the database</span>
<span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">user</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">String</span><span class="p">(</span><span class="s">&quot;jack&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">//DWS username</span>
<span class="n">String</span><span class="w"> </span><span class="n">pass</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">String</span><span class="p">(</span><span class="s">&quot;********&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">//DWS Password</span>
<span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">tablename</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">String</span><span class="p">(</span><span class="s">&quot;migration_table&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">//Define table information.</span>
<span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">delimiter</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">String</span><span class="p">(</span><span class="s">&quot;|&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">//Define a delimiter.</span>
<span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">encoding</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">String</span><span class="p">(</span><span class="s">&quot;UTF8&quot;</span><span class="p">);</span><span class="w"> </span><span class="c1">//Define a character set.</span>
<span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">driver</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s">&quot;org.postgresql.Driver&quot;</span><span class="p">;</span>
<span class="w"> </span><span class="n">StringBuffer</span><span class="w"> </span><span class="n">buffer</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">StringBuffer</span><span class="p">();</span><span class="w"> </span><span class="c1">//Define the buffer to store formatted data.</span>
<span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="c1">//Obtain the query result set of the source database.</span>
<span class="w"> </span><span class="n">ResultSet</span><span class="w"> </span><span class="n">rs</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">getDataSet</span><span class="p">();</span>
<span class="w"> </span><span class="c1">//Traverse the result set and obtain records row by row.</span>
<span class="w"> </span><span class="c1">//The values of columns in each record are separated by the specified delimiter and end with a newline character to form strings.</span>
<span class="w"> </span><span class="c1">////Add the strings to the buffer.</span>
<span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="n">rs</span><span class="p">.</span><span class="na">next</span><span class="p">())</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">buffer</span><span class="p">.</span><span class="na">append</span><span class="p">(</span><span class="n">rs</span><span class="p">.</span><span class="na">getString</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">delimiter</span>
<span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">rs</span><span class="p">.</span><span class="na">getString</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">delimiter</span>
<span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">rs</span><span class="p">.</span><span class="na">getString</span><span class="p">(</span><span class="mi">3</span><span class="p">)</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">delimiter</span>
<span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">rs</span><span class="p">.</span><span class="na">getString</span><span class="p">(</span><span class="mi">4</span><span class="p">)</span>
<span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot;\n&quot;</span><span class="p">);</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="n">rs</span><span class="p">.</span><span class="na">close</span><span class="p">();</span>
<span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="c1">//Connect to the target database.</span>
<span class="w"> </span><span class="n">Class</span><span class="p">.</span><span class="na">forName</span><span class="p">(</span><span class="n">driver</span><span class="p">);</span>
<span class="w"> </span><span class="n">Connection</span><span class="w"> </span><span class="n">conn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">DriverManager</span><span class="p">.</span><span class="na">getConnection</span><span class="p">(</span><span class="n">url</span><span class="p">,</span><span class="w"> </span><span class="n">user</span><span class="p">,</span><span class="w"> </span><span class="n">pass</span><span class="p">);</span>
<span class="w"> </span><span class="n">BaseConnection</span><span class="w"> </span><span class="n">baseConn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="n">BaseConnection</span><span class="p">)</span><span class="w"> </span><span class="n">conn</span><span class="p">;</span>
<span class="w"> </span><span class="n">baseConn</span><span class="p">.</span><span class="na">setAutoCommit</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span>
<span class="w"> </span><span class="c1">//Initialize table information.</span>
<span class="w"> </span><span class="n">String</span><span class="w"> </span><span class="n">sql</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s">&quot;Copy &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">tablename</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot; from STDIN DELIMITER &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot;'&quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">delimiter</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot;'&quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot; ENCODING &quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot;'&quot;</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="n">encoding</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="s">&quot;'&quot;</span><span class="p">;</span>
<span class="w"> </span><span class="c1">//Submit data in the buffer.</span>
<span class="w"> </span><span class="n">CopyManager</span><span class="w"> </span><span class="n">cp</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">CopyManager</span><span class="p">(</span><span class="n">baseConn</span><span class="p">);</span>
<span class="w"> </span><span class="n">StringReader</span><span class="w"> </span><span class="n">reader</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">new</span><span class="w"> </span><span class="n">StringReader</span><span class="p">(</span><span class="n">buffer</span><span class="p">.</span><span class="na">toString</span><span class="p">());</span>
<span class="w"> </span><span class="n">cp</span><span class="p">.</span><span class="na">copyIn</span><span class="p">(</span><span class="n">sql</span><span class="p">,</span><span class="w"> </span><span class="n">reader</span><span class="p">);</span>
<span class="w"> </span><span class="n">baseConn</span><span class="p">.</span><span class="na">commit</span><span class="p">();</span>
<span class="w"> </span><span class="n">reader</span><span class="p">.</span><span class="na">close</span><span class="p">();</span>
<span class="w"> </span><span class="n">baseConn</span><span class="p">.</span><span class="na">close</span><span class="p">();</span>
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="n">ClassNotFoundException</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">e</span><span class="p">.</span><span class="na">printStackTrace</span><span class="p">(</span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">);</span>
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="n">SQLException</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">e</span><span class="p">.</span><span class="na">printStackTrace</span><span class="p">(</span><span class="n">System</span><span class="p">.</span><span class="na">out</span><span class="p">);</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="n">Exception</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">e</span><span class="p">.</span><span class="na">printStackTrace</span><span class="p">();</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="c1">//******************************** </span>
<span class="w"> </span><span class="c1">//Return the query result from the source database.</span>
<span class="w"> </span><span class="c1">//********************************* </span>
<span class="w"> </span><span class="kd">private</span><span class="w"> </span><span class="kd">static</span><span class="w"> </span><span class="n">ResultSet</span><span class="w"> </span><span class="nf">getDataSet</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">ResultSet</span><span class="w"> </span><span class="n">rs</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="kc">null</span><span class="p">;</span>
<span class="w"> </span><span class="k">try</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">Class</span><span class="p">.</span><span class="na">forName</span><span class="p">(</span><span class="s">&quot;com.mysql.jdbc.Driver&quot;</span><span class="p">).</span><span class="na">newInstance</span><span class="p">();</span>
<span class="w"> </span><span class="n">Connection</span><span class="w"> </span><span class="n">conn</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">DriverManager</span><span class="p">.</span><span class="na">getConnection</span><span class="p">(</span><span class="s">&quot;jdbc:mysql://10.119.179.227:3306/jack?useSSL=false&amp;allowPublicKeyRetrieval=true&quot;</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;jack&quot;</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;********&quot;</span><span class="p">);</span>
<span class="w"> </span><span class="n">Statement</span><span class="w"> </span><span class="n">stmt</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">conn</span><span class="p">.</span><span class="na">createStatement</span><span class="p">();</span>
<span class="w"> </span><span class="n">rs</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">stmt</span><span class="p">.</span><span class="na">executeQuery</span><span class="p">(</span><span class="s">&quot;select * from migration_table&quot;</span><span class="p">);</span>
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="n">SQLException</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">e</span><span class="p">.</span><span class="na">printStackTrace</span><span class="p">();</span>
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">catch</span><span class="w"> </span><span class="p">(</span><span class="n">Exception</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">e</span><span class="p">.</span><span class="na">printStackTrace</span><span class="p">();</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="n">rs</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="p">}</span>
</pre></div></td></tr></table></div>
</div>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="dws_04_0088.html">JDBC-Based Development</a></div>
</div>
</div>
View Git Blame Copy Permalink