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5 min readTo add ALTER SESSION privileges to a user in Oracle SQL, you can use the GRANT statement. By executing the GRANT ALTER SESSION TO username; command, you can grant the user the ability to alter their session settings. This can be useful for users who need to adjust certain settings for their specific requirements during a session. To revoke this privilege, you can use the REVOKE statement in a similar manner.
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3 min readIn Oracle, you can group query results based on a particular column using the GROUP BY clause in a SQL query. To group query results based on a job column, you can use a query like:SELECT job, COUNT(*) as total FROM employees GROUP BY job;This query will group all the employees based on their job titles and count the total number of employees in each job category.
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5 min readTo use a window function with a case statement in Oracle SQL, you can include the case statement inside the window function's definition. This allows you to apply conditional logic to the rows in the window partition before the window function is applied.For example, if you want to calculate the sum of a column based on a condition using a window function, you can use a case statement within the sum function.
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5 min readThe "not in" operator in Oracle SQL is used to retrieve records that do not match the values specified in a list. It functions as the opposite of the "in" operator.To use the "not in" operator, you would typically structure your query like this: SELECT column_names FROM table_name WHERE column_name NOT IN (value1, value2, ...);The values listed in the parentheses are the ones that you want to exclude from the query results.
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4 min readTo connect to an Oracle database with Python, you can use the cx_Oracle library. First, you need to install the library by using pip install cx_Oracle. Then, you need to import the library in your Python script by using import cx_Oracle. Next, you can establish a connection to the Oracle database by using the cx_Oracle.connect() function and providing the necessary connection details such as username, password, host, and service name.
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3 min readTo get the system date and time in Oracle SQL, you can use the SYSDATE function. This function returns the current date and time in the database server's time zone. You can simply call SYSDATE in your SQL query to retrieve the system date and time. Additionally, you can also use the CURRENT_TIMESTAMP function to get the current timestamp, which includes both date and time information.
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4 min readTo create custom authentication in Oracle APEX, you can use the built-in authentication schemes or create your own custom authentication scheme.To create a custom authentication scheme, you will need to write PL/SQL code to authenticate users against a custom table or source. This can involve validating user credentials, checking against a database table, or integrating with an external authentication system.
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6 min readTo insert binary XML into an Oracle table, you can use the DBMS_LOB package provided by Oracle. First, you need to convert the binary XML into a BLOB (Binary Large Object) data type using PL/SQL code. You can then insert this BLOB data into a table column of type BLOB.
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6 min readTo select and join more than two tables in Oracle, you can use the JOIN keyword along with the appropriate join conditions. You can join three or more tables by specifying additional tables in the JOIN clause using the ON keyword to define the join condition.For example, if you have tables A, B, and C that you want to join, you can write a SQL query like this:SELECT * FROM tableA JOIN tableB ON tableA.column = tableB.column JOIN tableC ON tableB.column = tableC.
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2 min readTo select the average from row results in Oracle, you can use the AVG() function in a SQL query. This function calculates the average value of a numeric column or expression.
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4 min readTo store a JSON array in Oracle, you can use the JSON data type introduced in Oracle Database 12c. You can define a column with the JSON data type and store the JSON array as a string in that column. Oracle also provides functions and operators for working with JSON data, such as JSON_OBJECT, JSON_ARRAY, JSON_VALUE, and JSON_QUERY. Additionally, you can use the PL/SQL JSON API to work with JSON data in Oracle.