Posts (page 68)
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5 min readTo delete an instance of a chart using chart.js, you can first retrieve the chart instance that you want to delete by using the Chart.get(chartId) method. Once you have the chart instance, you can call the destroy() method on it to remove the chart from the DOM and clean up any associated resources. This will effectively delete the instance of the chart and free up any memory that was being used. Remember to also remove any references to the chart instance to prevent memory leaks.
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4 min readTo take the difference of dates in Oracle, you can use the DATEDIFF function along with the appropriate date formats. This function calculates the difference between two dates and returns the result in the desired units (days, months, years, etc.). You can also use simple subtraction to calculate the difference between two dates, which will return the result in days. Additionally, you can use the INTERVAL keyword to specify the unit of measurement for the date difference calculation.
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5 min readTo convert a Unix timestamp to a date using Chart.js, you can use the built-in Date object in JavaScript. First, you can create a new Date object and pass the Unix timestamp as a parameter. Then, you can use various methods of the Date object to extract the date in the format you desire, such as using getDate(), getMonth(), getFullYear(), getHours(), getMinutes(), and getSeconds().
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5 min readTo add a y-axis label in chart.js with vue.js, you can use the 'scales' option in your chart configuration. Within the 'scales' key, you can specify the 'yAxes' key to define the properties of the y-axis. Within the 'yAxes' key, you can set the 'scaleLabel' key to specify the label for the y-axis. Here is an example of how you can add a y-axis label in chart.js with vue.
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4 min readTo get a substring after a specific pattern in Oracle, you can use the SUBSTR function in combination with the INSTR function. First, use INSTR to find the position of the specific pattern in the string. Then, use SUBSTR to extract the substring starting from the position after the specific pattern.
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3 min readTo sort tooltip values in Chart.js, you can use the tooltips.callbacks.label function to customize the tooltip label. Within this function, you can access the tooltip item array and sort the values as needed before displaying them in the tooltip. By sorting the tooltip values, you can present the data in a more organized and meaningful way for the users.[rating:868fd947-1080-4ee7-96f9-1ec8a84c1019]How to customize the sorting function for tooltip values in chart.js.
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3 min readIn Oracle, you can sort varchar values using the ORDER BY clause in a SELECT statement. By default, varchar values are sorted in ascending order. If you want to sort them in descending order, you can use the DESC keyword after the column name in the ORDER BY clause. Keep in mind that varchar values are sorted alphabetically, so numbers and special characters may affect the sorting order.
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4 min readTo load data values from a cookie into chart.js, you first need to retrieve the data stored in the cookie using JavaScript. You can use the document.cookie property to access the cookie data and then parse it to extract the values you need for your chart.Once you have extracted the data values, you can use them to update the dataset of your chart in chart.js. You will need to loop through the data and update the appropriate data points or labels in the chart dataset.
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6 min readTo retrieve deleted data from tables in Oracle, you can use the Flashback Query feature. Flashback Query allows you to query a table and see its contents at a previous point in time, including the data that has been deleted. You can use the AS OF clause in your SELECT statement to specify a timestamp or SCN (System Change Number) to retrieve the data as it existed at that point in time.
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4 min readTo get the size of a chart without labels in Chart.js, you can use the "width" and "height" properties of the chart object. You can access these properties after initializing the chart using the Chart.js library. By accessing the "width" and "height" properties, you can determine the dimensions of the chart canvas without including the space taken up by the labels.
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6 min readTo apply gradient color in chart.js, you can create a gradient object using the CanvasRenderingContext2D.createLinearGradient() method. You can then define the colors and positions of the gradient stops within the gradient object. Finally, you can set the fill style of the chart element to the gradient object you created. This will apply the gradient color to the chart element.[rating:868fd947-1080-4ee7-96f9-1ec8a84c1019]What are some examples of charts where gradient colors work best.
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5 min readTo add chart.js type definition to your project, you need to install the @types/chart.js package using a package manager like npm or yarn. This package provides TypeScript definitions for chart.js library, allowing you to use it in a TypeScript project with proper type checking and code completion.To install the @types/chart.js package, you can run the following command in your project directory: npm install --save-dev @types/chart.