Posts (page 53)
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6 min readTo zoom in or out with wxPython, you can use the SetScale method of wx.GraphicsContext. You can create a GraphicsContext object using the CreateGraphicsContext method of a wx.Window object. Once you have the GraphicsContext, you can use its SetScale method to zoom in or out by specifying values for the x and y scales. For example, to zoom in on an object by a factor of 2, you can use context.SetScale(2, 2). Similarly, to zoom out by a factor of 0.5, you can use context.SetScale(0.5, 0.5).
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5 min readTo fetch records between two timestamps in Oracle, you can use the "BETWEEN" keyword along with the "TO_TIMESTAMP" function. You can specify the start and end timestamps in the query to retrieve records that fall within that time range.
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4 min readWhen choosing the size of a tablespace in Oracle, it is important to consider factors such as the amount of data that will be stored in the tablespace, the growth rate of the data, and the allocated budget for storage. It is recommended to allocate enough space to accommodate the current data as well as future growth, to prevent performance issues and the need for frequent resizing of the tablespace.
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3 min readIn Oracle, you can parse JSON data using the JSON_VALUE, JSON_QUERY, and JSON_TABLE functions. The JSON_VALUE function is used to extract scalar values from JSON objects, while JSON_QUERY is used to extract object or array values. JSON_TABLE function is used to convert JSON data into relational format.You can also use the dot notation to navigate through the JSON hierarchy in Oracle. For example, you can access nested objects by specifying the key path using the dot notation.
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6 min readTo update a CLOB (Character Large Object) field in Oracle, you can use the dbms_lob package. First, you need to select the CLOB data using a select statement. Then, use the dbms_lob.write procedure to update the CLOB data.Here is an example of how you can update a CLOB field in Oracle: DECLARE l_clob CLOB; BEGIN SELECT clob_column INTO l_clob FROM your_table WHERE condition; dbms_lob.write(l_clob, DBMS_LOB.
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8 min readTo run Oracle PL/SQL in Python, you can use the cx_Oracle module, which allows Python programs to connect to Oracle databases. With cx_Oracle, you can execute SQL and PL/SQL statements, fetch data from Oracle databases, and interact with Oracle stored procedures, functions, and packages.To get started, you need to install the cx_Oracle module in your Python environment.
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5 min readIn Oracle, updating table statistics is important for the query optimizer to generate efficient execution plans. To update table statistics in Oracle, you can use the DBMS_STATS package.You can gather statistics for a specific table or schema using the DBMS_STATS package procedures such as GATHER_TABLE_STATS or GATHER_SCHEMA_STATS. These procedures collect information about the data distribution in the table, index statistics, and column histograms.
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5 min readIn Oracle, if a subquery returns more than one value, it can cause an error when used in a query. To resolve this issue, you can try using the IN or ANY keyword to compare the results of the subquery with a single value. Another option is to use the MAX() or MIN() functions to aggregate the results of the subquery into a single value. You can also use the ROWNUM or ROW_NUMBER() function to limit the number of results returned by the subquery.
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4 min readTo sort by a dynamic column in Oracle, you can use a CASE statement in the ORDER BY clause. This allows you to dynamically select the column based on a condition. For example, you can use a CASE statement to sort by different columns depending on user input or other factors. This flexibility gives you the ability to customize the sorting logic in your queries based on changing requirements. By using a CASE statement in the ORDER BY clause, you can achieve dynamic sorting in Oracle queries.
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5 min readTo draw polygons with Point2D in wxPython, you need to first create a list of Point2D objects representing the vertices of the polygon. You can then use the DrawPolygon method of the device context (DC) to draw the polygon on a wxPython canvas.Here's a simple example code snippet that demonstrates how to draw a polygon with Point2D in wxPython: import wx class MyPanel(wx.Panel): def __init__(self, parent): super().__init__(parent) self.Bind(wx.EVT_PAINT, self.
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6 min readTo split string words with REGEXP_SUBSTR in Oracle SQL, you can use the following syntax:SELECT REGEXP_SUBSTR(column_name, '[^ ]+', 1, LEVEL) AS word FROM table_name CONNECT BY LEVEL <= REGEXP_COUNT(column_name, '[^ ]+');In this query:"column_name" is the column containing the string you want to split."table_name" is the name of the table containing the column.
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5 min readTo select the average value from a count in Oracle SQL, you can use a subquery to first obtain the count and then calculate the average. Here is an example query:SELECT AVG(cnt) as average_count FROM ( SELECT COUNT(*) as cnt FROM your_table GROUP BY some_column );In this query, "your_table" is the table from which you want to count the records, and "some_column" is the column you want to group by.