我有三个表，其中两个在master_biz数据库中，第三个在master_custom数据库中。
master_biz.legend_asset表
<style type="text/css">
table.tableizer-table {
font-size: 12px;
border: 1px solid #CCC;
font-family: Arial, Helvetica, sans-serif;
}
.tableizer-table td {
padding: 4px;
margin: 3px;
border: 1px solid #CCC;
}
.tableizer-table th {
background-color: #104E8B;
color: #FFF;
font-weight: bold;
}
</style>
<table class="tableizer-table">
<thead>
<tr class="tableizer-firstrow">
<th>id</th>
<th>did</th>
<th>roa_id</th>
<th>make</th>
<th>model</th>
<th>type</th>
<th>function</th>
<th>status</th>
<th>owner</th>
<th>serial</th>
<th>asset_tag</th>
<th>rfid</th>
<th>date_edit</th>
<th>user_edit</th>
<th>a_notes</th>
<th>owner_admin</th>
<th>owner_tech</th>
</tr>
</thead>
<tbody>
<tr>
<td>2</td>
<td>0</td>
<td>1</td>
<td>Tenable</td>
<td>Nessus</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/23/2016 16:19</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>3</td>
<td>0</td>
<td>1</td>
<td>Tenable</td>
<td>Nessus</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/20/2016 18:59</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>4</td>
<td>0</td>
<td>2</td>
<td>Microsoft</td>
<td>Windows Server Standard 2012 R2</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/20/2016 18:59</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>5</td>
<td>0</td>
<td>0</td>
<td>Solarwinds</td>
<td>Kiwi CAT Tools</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/20/2016 18:59</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>6</td>
<td>0</td>
<td>1</td>
<td>Splunk</td>
<td>Enterprise</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/20/2016 18:59</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>7</td>
<td>0</td>
<td>1</td>
<td>Splunk</td>
<td>Enterprise Support</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/23/2016 16:19</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>8</td>
<td>0</td>
<td>1</td>
<td>VMware</td>
<td>vSphere 5/6 Support Standard</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/20/2016 18:59</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>9</td>
<td>0</td>
<td>1</td>
<td>VMware</td>
<td>vSphere 5/6 Support Enterprise Plus</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/20/2016 18:59</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
<tr>
<td>10</td>
<td>0</td>
<td>1</td>
<td>VMware</td>
<td>vCenter 5/6 Support Standard</td>
<td> </td>
<td>Unknown</td>
<td>Production</td>
<td> </td>
<td> </td>
<td>NULL</td>
<td> </td>
<td>5/20/2016 18:59</td>
<td>1</td>
<td> </td>
<td>0</td>
<td>0</td>
</tr>
</tbody>
</table>
master_biz.asset_location表
<style type="text/css">
table.tableizer-table {
font-size: 12px;
border: 1px solid #CCC;
font-family: Arial, Helvetica, sans-serif;
}
.tableizer-table td {
padding: 4px;
margin: 3px;
border: 1px solid #CCC;
}
.tableizer-table th {
background-color: #104E8B;
color: #FFF;
font-weight: bold;
}
</style>
<table class="tableizer-table">
<thead>
<tr class="tableizer-firstrow">
<th>iid</th>
<th>location</th>
<th>floor</th>
<th>room</th>
<th>plate</th>
<th>panel</th>
<th>punch</th>
<th>zone</th>
<th>rack</th>
<th>shelf</th>
<th>date_edit</th>
<th>user_edit</th>
<th>l_notes</th>
</tr>
</thead>
<tbody>
<tr>
<td>1</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>2</td>
<td>Lab</td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>3</td>
<td>Production</td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>4</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>5</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>6</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>7</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>8</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>9</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td> </td>
</tr>
<tr>
<td>10</td>
<td> </td>
<td>0</td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td> </td>
<td>0000-00-00 00:00:00</td>
<td>1</td>
<td></td>
</tr>
</tbody>
</table>
master_custom.custom_app_table_4表
<style type="text/css">
table.tableizer-table {
font-size: 12px;
border: 1px solid #CCC;
font-family: Arial, Helvetica, sans-serif;
}
.tableizer-table td {
padding: 4px;
margin: 3px;
border: 1px solid #CCC;
}
.tableizer-table th {
background-color: #104E8B;
color: #FFF;
font-weight: bold;
}
</style>
<table class="tableizer-table">
<thead>
<tr class="tableizer-firstrow">
<th>id</th>
<th>2_2</th>
<th>8_2</th>
<th>9_2</th>
<th>10_2</th>
<th>11_2</th>
<th>12_2</th>
<th>13_2</th>
</tr>
</thead>
<tbody>
<tr>
<td>2</td>
<td>Software License</td>
<td>Tenable</td>
<td>Professional</td>
<td>1</td>
<td>5/10/2017</td>
<td>2190</td>
<td> </td>
</tr>
<tr>
<td>3</td>
<td>Software License</td>
<td>Tenable</td>
<td>Professional</td>
<td>1</td>
<td>5/10/2017</td>
<td>2190</td>
<td> </td>
</tr>
<tr>
<td>4</td>
<td>Software License</td>
<td>Microsoft</td>
<td>Standard</td>
<td>10</td>
<td>5/3/2016</td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>5</td>
<td>Software Maintenance</td>
<td>Solarwinds</td>
<td>N/A</td>
<td>4</td>
<td>10/30/2016</td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>6</td>
<td>Software License</td>
<td>Splunk</td>
<td>20GB</td>
<td>1</td>
<td>6/1/2016</td>
<td>60000</td>
<td> </td>
</tr>
<tr>
<td>7</td>
<td>Software Maintenance</td>
<td>Splunk</td>
<td>Enterprise</td>
<td>1</td>
<td>6/1/2016</td>
<td>0</td>
<td> </td>
</tr>
<tr>
<td>8</td>
<td>Software Maintenance</td>
<td>VMware</td>
<td>24x7 Production</td>
<td>30</td>
<td>5/10/2017</td>
<td> </td>
<td> </td>
</tr>
<tr>
<td>9</td>
<td>Software Maintenance</td>
<td>VMware</td>
<td>Subscription Only</td>
<td>46</td>
<td>5/10/2017</td>
<td>4375</td>
<td> </td>
</tr>
<tr>
<td>10</td>
<td>Software Maintenance</td>
<td>VMware</td>
<td>Subscription Only</td>
<td>3</td>
<td>5/10/2017</td>
<td>530</td>
<td></td>
</tr>
</tbody>
</table>
我目前正在使用以下代码加入其中两个表格。 这段代码可行，但是我留下了许多额外的列和列名，这些列和列名并不能准确地表示数据。
SELECT *
FROM master_biz.legend_asset
RIGHT JOIN master_custom.custom_app_table_4
USING (id);
我想使用id列和iid列加入所有这三个表。我还需要能够只选择我需要的列。
我认为应该怎么做：
SELECT
master_custom.custom_app_table_4.ID AS ASSET_ID,
master_custom.custom_app_table_4.2_2 AS CONTRACT_TYPE,
master_custom.custom_app_table_4.8_2 AS SUPPLIER,
master_custom.custom_app_table_4.9_2 AS SUPPORT_LEVEL,
master_custom.custom_app_table_4.10_2 AS QUANTITY,
master_custom.custom_app_table_4.11_2 AS LICENSE_EXPIRATION,
master_custom.custom_app_table_4.12_2 AS LICENSE_COST,
master_biz.legend_asset.roa_id AS ORGANIZATION_NUMBER,
master_biz.legend_asset.make AS MANUFACTURER,
master_biz.legend_asset.model AS PRODUCT,
master_biz.legend_asset.status AS STATUS
FROM
master_custom.custom_app_table_4,
master_biz.legend_asset
Left JOIN
master_biz.legend_asset
ON
master_custom.custom_app_table_4.ASSET_ID=master_biz.legend_asset.ID
执行时收到的错误代码：
#1066 - Not unique table/alias: 'legend_asset'
如果有人知道如何实现这一目标，并愿意分享，我们将不胜感激。
我原来的帖子在这里： MySQL and Splunk - Select and Join 由于主要问题已得到解决，我觉得提出另一个问题是为了让未来帮助寻求者不那么忙。
答案 0 :(得分：1)
您重新加载同一张桌子两次：</ p>
FROM
master_custom.custom_app_table_4,
master_biz.legend_asset <---#1
Left JOIN
master_biz.legend_asset <---#2
表格中至少有两个提到的名称必须别名，例如：
FROM
master_custom.custom_app_table_4,
master_biz.legend_asset AS foo
Left JOIN
master_biz.legend_asset AS bar
然后根据需要在查询中的其他位置使用foo和bar。
答案 1 :(得分：1)
看起来你加入了＆＃34; master_biz.legend_asset＆＃34;表两次。您需要为每个提供别名才能使其工作（请参阅下面的mbla1和mbla2）。您还需要为Select子句中的每一列使用这些别名。
SELECT
master_custom.custom_app_table_4.ID AS ASSET_ID,
master_custom.custom_app_table_4.2_2 AS CONTRACT_TYPE,
master_custom.custom_app_table_4.8_2 AS SUPPLIER,
master_custom.custom_app_table_4.9_2 AS SUPPORT_LEVEL,
master_custom.custom_app_table_4.10_2 AS QUANTITY,
master_custom.custom_app_table_4.11_2 AS LICENSE_EXPIRATION,
master_custom.custom_app_table_4.12_2 AS LICENSE_COST,
mbla1.roa_id AS ORGANIZATION_NUMBER, --Aliased column
mbla1.make AS MANUFACTURER, --Aliased column
mbla2.model AS PRODUCT, --Aliased column
mbla2.status AS STATUS --Aliased column
FROM
master_custom.custom_app_table_4,
master_biz.legend_asset mbla1 --Aliased table
Left JOIN
master_biz.legend_asset mbla2 --Aliased table
ON
master_custom.custom_app_table_4.ASSET_ID=master_biz.legend_asset.ID