Posts (page 68)
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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.
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5 min readTo change the date format in chart.js, you can use the "time" properties in the options object when creating your chart. Within the "scales" object, you can specify the format you want for the x-axis labels by setting the "type" property to "time" and the "time" property to an object with a "displayFormats" property where you can define the format you prefer for the date.
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5 min readTo display a line chart using Chart.js in React.js, you will first need to install the Chart.js library and the react-chartjs-2 wrapper. You can do this by running the following command in your project directory:npm install chart.js react-chartjs-2Once the installation is complete, you can import the Line component from 'react-chartjs-2' in your React component file. You can then create a data object that contains the labels and datasets for your chart.
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5 min readTo dynamically update data in chart.js, you can first store your chart instance as a variable so that you can easily access and update it later. Whenever you want to update the data, you can simply modify the data property of your chart instance with the new data that you want to display. Once you have updated the data, you can call the update() method on your chart instance to apply the changes and redraw the chart with the updated data.
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3 min readTo manage the y-axis on a chart using chart.js, you can customize the y-axis by setting various options in the configuration object. You can control elements such as the minimum and maximum values of the y-axis, the step size, the grid lines, the labels, and the axis title. You can also format the y-axis labels using callback functions to display the values in a specific way. Additionally, you can display multiple y-axes on the same chart to compare different datasets.