Posts (page 114)
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6 min readTo generate a Rc from a reference to T in Rust, you can use the Rc::clone method. This method creates a new reference-counted pointer to the same underlying data as the original reference. Here's an example: use std::rc::Rc; fn main() { let data = String::from("Hello, Rust!"); let ptr = Rc::new(&data); let cloned_ptr = Rc::clone(&ptr); println!("Original data: {}", *ptr); println.
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7 min readTo implement a trait on an integer type in Rust, you first need to define the trait using the trait keyword followed by the trait name and its methods. Then, you can implement the trait for a specific integer type by using the impl keyword followed by the trait name and the integer type. Inside the impl block, you can define the implementation of the trait methods for that particular integer type. You can then use the methods defined in the trait on instances of the integer type.
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4 min readInvalid identifier errors in Oracle typically occur when you try to reference a table, column, or object that does not exist in the database. To avoid these errors, make sure you double-check the spelling of the identifier in your SQL statements. It's also important to be aware of the scope of your identifiers, as they may not be accessible in certain contexts.
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3 min readTo break out of a loop in Rust and return a value, you can use the break keyword to exit the loop and the return keyword to return a value from the function containing the loop. By combining these two keywords, you can break out of the loop and immediately return a value. Just make sure to place the value you want to return after the return keyword. This way, you can effectively break out of a loop and return a value in Rust.
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5 min readIn Oracle functions, dividing by zero can result in a runtime error. To handle this situation, you can use the NULLIF function in combination with a conditional statement to check if the denominator is zero before performing the division operation. By using NULLIF, you can return a NULL value instead of an error when dividing by zero. This allows you to handle the divide by zero scenario gracefully and continue with the function execution without crashing.
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7 min readIn Rust, the Specification Pattern can be implemented by defining a trait that represents the specification interface. This trait should have a single method that takes a reference to an object and returns a boolean value indicating whether the object meets the criteria specified by the specification.You can then create concrete implementations of this trait for different types of specifications. These implementations can check specific conditions on the object and return the result accordingly.
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8 min readTo fix the "ORA-01735: invalid ALTER TABLE option" error in Oracle 11g, you can follow these steps:Check the syntax of your ALTER TABLE statement to make sure it is correct according to the Oracle 11g documentation. Make sure you are using valid options for the ALTER TABLE command. Common options include adding columns, modifying columns, dropping columns, and adding constraints. Check if there are any typos or errors in your ALTER TABLE statement that may be causing the error.
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5 min readTo get data from enums in Rust, you can use pattern matching to access the values associated with each variant. Enums in Rust can have associated data with them, which can be accessed by matching on the enum variant.For example, if you have an enum like: enum Color { RGB(u8, u8, u8), CMYK(u8, u8, u8, u8), } You can access the associated data by matching on the enum variant like this: let color = Color::RGB(255, 0, 0); match color { Color::RGB(r, g, b) => { println.
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4 min readIn Rust, you can convert ASCII characters to integers by using the as keyword to perform a cast. For example, if you have a variable c of type char representing an ASCII character, you can convert it to its corresponding integer value by casting it to the u8 type like this: let c = 'A'; let num = c as u8; This will convert the character 'A' to the integer 65, which is the ASCII value of the character 'A'.
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6 min readIn Oracle, the error message "column ambiguously defined" occurs when a column is referenced in a query that exists in more than one of the tables being joined, but the database engine cannot tell from which table the column should be selected.To fix this error, you need to explicitly specify which table the column belongs to by prefixing the column name with the table alias or table name in the SELECT statement.
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4 min readTo remove null characters from a string in Rust, you can use the chars method to iterate over each character in the string and filter out the null characters. Here is an example code snippet to achieve this: fn remove_null_chars(input: &str) -> String { input.chars().filter(|&c| c != '\0').collect() } fn main() { let input = "Hello\0World"; let result = remove_null_chars(input); println.
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8 min readTo merge two or more unknown tables into one table in Oracle, you can use the UNION ALL keyword in a SQL query. This keyword allows you to combine the results of multiple SELECT statements into a single result set.First, you need to identify the columns that are common among the tables you want to merge. Then, you can write a SELECT statement for each table, selecting the common columns and any additional columns you want to include in the merged table.