Add table value mapping

Overview

In the Value Mapping configuration of a dashboard chart, configure three mapping rules to replace empty values: map Empty String to 0, map NaN to 0, and map Null or undefined to 0. Example query and analysis statement: * | select split_part(request_uri,'?',1) as path, count(1) as pv, '' as empty, 'NaN' as nan group by split_part(request_uri,'?',1) order by pv desc limit 10.

1. Query and analysis: You can query and analyze logs in the console. For example, you can retrieve logs, aggregate log data, and generate statistics.

2. Add a chart: Each dashboard consists of one or more charts. Each chart is based on one or more query and analysis statements.

3. Add a value mapping: Convert string values in a table to numbers.

Step 1: Query and analysis

1. Log on to the Simple Log Service console. In the Projects section, click the project you want.

   

2. On the Log Storage > Logstores tab, click the logstore you want.

   

3. Enter a query and analysis statement, and then click Last 15 Minutes to set the time range.

   For example, to query the paths and number of imported files, use the following statement:

   * | select split_part(request_uri,'?',1) as path, count(1) as pv, '' as empty, 'NaN' as nan group by split_part(request_uri,'?',1) order by pv desc limit 10

Step 2: Add a chart

1. In the left-side navigation pane, choose Dashboard > Dashboards. In the Dashboard list, click the dashboard you want. In the upper-right corner of the dashboard page, click Edit. In edit mode, choose Add > Add Chart.

   

2. In the General Configurations section, select the icon for Chart Type. On the Query and Analysis tab, select your data source (in this case, LogStore (SQL)), select the target Logstore, and enter a query statement.

   In the upper-right corner, select a time range such as Last 15 Minutes and click Apply.

   Set Chart Type to Table. An example query: * | select *.

Step 3: Add a value mapping