Syntax and examples of color functions - Simple Log Service

This topic describes the syntax of color functions. This topic also provides examples on how to use the functions.

The following table describes the color functions that are supported by Simple Log Service.

Important

If you want to use strings in analytic statements, you must enclose the strings in single quotation marks (''). Strings that are not enclosed or strings that are enclosed in double quotation marks ("") indicate field names or column names. For example, 'status' indicates the status string, and status or "status" indicates the status log field.
When you use color functions in the Simple Log Service console, the display of query and analysis results is compromised. To avoid this issue, we recommend that you view the query and analysis results on your server.
- Display of query and analysis results in the console
- Display of query and analysis results on a server

Function	Syntax	Description	Supported in SQL	Supported in SPL
bar function	bar(x, width)	Returns a part of an ANSI bar chart. You can configure the width parameter to specify the width of the ANSI bar chart. However, you cannot configure the high_color or low_color parameter to specify the colors for the chart. The default values of the high_color and low_color parameters are used. The default value of the low_color parameter is red, and the default value of the high_color parameter is green. In addition, you can configure x to specify the length of the part that is returned by the function.	√	×
bar function	bar(x, width, low_color, high_color)	Returns a part of an ANSI bar chart. You can configure the width parameter to specify the width of the ANSI bar chart. You can also configure the high_color and low_color parameters to specify custom colors for the chart. In addition, you can configure x to specify the length of the part that is returned by the function.	√	×
color function	color(string)	Converts a color string to a color type.	√	×
	color(x, low, high, low_color, high_color)	Returns a color between high_color and low_color based on the portions of high_color and low_color. The portions are determined by the proportion of x between high and low.	√	×
	color(y, low_color, high_color)	Returns a color between high_color and low_color based on the portions of high_color and low_color. The portions are determined by y.	√	×
render function	render(boolean expression)	Returns results by using color rendering. If the Boolean expression evaluates to true, the function returns a green tick. If the Boolean expression evaluates to false, the function returns a red cross.	√	×
render function	render(x, color)	Returns results by using custom color rendering.	√	×
rgb function	rgb(red, green, blue)	Returns a color value based on an RGB value.	√	×

bar function

The bar function returns an ANSI bar chart.

Syntax

If you use the following syntax, the function returns a part of an ANSI bar chart. You can configure the width parameter to specify the width of the ANSI bar chart. However, you cannot configure the high_color or low_color parameter to specify the colors for the chart. The default values of the high_color and low_color parameters are used. The default value of the low_color parameter is red, and the default value of the high_color parameter is green. In addition, you can configure x to specify the length of the part that is returned by the function.
```
bar(x, width)
```
If you use the following syntax, the function returns a part of an ANSI bar chart. You can configure the width parameter to specify the width of the ANSI bar chart. You can also configure the high_color and low_color parameters to specify custom colors for the chart. In addition, you can configure x to specify the length of the part that is returned by the function.
```
bar(x, width, low_color, high_color)
```

Parameters

Parameter	Description
x	The proportion of the part that is returned by the function to the ANSI bar chart. The value of this parameter is of the double type. Valid values: [0,1].
width	The width of the ANSI bar chart.
low_color	The RGB value of the start color.
high_color	The RGB value of the end color.

Return value type

The varchar type.

Examples

Example 1: Obtain a part of an ANSI bar chart based on the proportion of page views (PVs) within a specified hour to the total PVs.

Query statement

* |
SELECT
  Method,
  bar(pv/m,100)
FROM(
    SELECT
      *,
      max(pv) over() AS m
    FROM(
        SELECT
          Method,
          count(1) AS pv
        FROM         internal-operation_log
        WHERE
          __date__ > '2021-09-10 00:00:00'
          AND __date__ < '2021-09-10 01:00:00'
        GROUP BY
          Method
      )
  )

Query and analysis results (console)
Query and analysis results (server)

Example 2: Obtain an ANSI bar chart that is displayed in red and white and has a width of 50.
- Query statement
```
* | SELECT bar(1,50,rgb(255,255,255),rgb(255,0,0))
```
- Query and analysis results (console)
- Query and analysis results (server)

color function

The color function returns the color that corresponds to a value.

Syntax

If you use the following syntax, the function converts a color string to a color type.
```
color(string)
```
If you use the following syntax, the function returns a color between high_color and low_color based on the portions of high_color and low_color. The portions are determined by the proportion of x between high and low.
```
color(x, low, high, low_color, high_color)
```
If you use the following syntax, the function returns a color between high_color and low_color based on the portions of high_color and low_color. The portions are determined by y.
```
color(y, low_color, high_color)
```

Parameters

Parameter	Description
x	The value of this parameter is of the double type.
y	The value of this parameter is of the double type. Valid values: [0,1].
low	The minimum value. The value of this parameter is of the double type.
high	The maximum value. The value of this parameter is of the double type.
low_color	The RGB value of the start color.
high_color	The RGB value of the end color.
string	The string. Valid values: black, red, green, yellow, blue, magenta, cyan, and white. The value can also be an RGB value in the Cascading Style Sheet (CSS) format. Example: #000.

Return value type

The color type.

Examples

Example 1: Convert a color string to a color type.
- Query statement
```
* | SELECT color('#000')
```
- Query and analysis results (console)
- Query and analysis results (server)
Example 2: Obtain a part of an ANSI bar chart. The remainder of the request_length field value is calculated. Then, the color function returns a color that corresponds to the remainder, and the bar function returns a part of an ANSI bar chart based on the color.
- Query statement
```
*|SELECT x,bar(10,10, color(x, 0,10, rgb(255,0,0), rgb(0,255,0)), rgb(0,255,0)) FROM(SELECT  *FROM (SELECT  request_length%10 x FROM  log))
```
- Query and analysis results (console)
- Query and analysis results (server)
Example 3: Obtain a part of an ANSI bar chart. The color function returns a color, and the bar function returns a part of an ANSI bar chart based on the color.
- Query statement
```
*|SELECT bar(10,10, color(0.3, rgb(255,255,255), rgb(255,0,0)), rgb(0,255,0))
```
- Query and analysis results (console)
- Query and analysis results (server)

render function

The render function returns results by using color rendering.

Syntax

If you use the following syntax, the function returns results by using color rendering. If the Boolean expression evaluates to true, the function returns a green tick. If the Boolean expression evaluates to false, the function returns a red cross.
```
render(boolean expression)
```
If you use the following syntax, the function returns results by using custom color rendering.
```
render(x, color)
```

Parameters

Parameter	Description
boolean expression	The Boolean expression.
x	The X coordinate. The value of this parameter is of the integer type.
color	The color. The value of this parameter is of the color type.

Return value type

The varchar type.

Examples

Example 1: Check whether the number of PVs is less than 1,000. The count function returns the number of PVs, and the render function determines whether the number of PVs is less than 1,000 and returns results by using color rendering. If the number of PVs is less than 1,000, the render function returns a green tick.
- Query statement
```
* | SELECT render(count(*)<1000)
```
- Query and analysis results (console)
- Query and analysis results (server)
Example 2: Obtain the total number of logs by using green rendering. The count function returns the total number of logs, and the render function returns results by using green rendering.
- Query statement
```
* | SELECT render(count(*),rgb(48,169,16))
```
- Query and analysis results (console)
- Query and analysis results (server)

rgb function

The rgb function returns a color value based on an RGB value.

Syntax

rgb(red, green, blue)

Parameters

Parameter	Description
red	The portion of red. Valid values: [0,255]. The value of this parameter is of the integer type.
green	The portion of green. Valid values: [0,255]. The value of this parameter is of the integer type.
blue	The portion of blue. Valid values: [0,255]. The value of this parameter is of the integer type.

Return value type

The color type.

Examples

Obtain a color value based on an RGB value.

Query statement
```
*|SELECT rgb(255,0,0)
```
Query and analysis results (console)
Query and analysis results (server)