Posts - Page 115 (page 115)
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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.
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6 min readTo check if a key is currently pressed in Rust, you can use the termion or crossterm crate to interact with the terminal and handle input. You can create an event loop that continuously checks for key press events and then perform the desired action based on the key pressed. This can be done by listening for specific key codes or characters using functions provided by the crate. By checking the current state of the terminal input, you can determine if a key is being pressed at any given moment.
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6 min readTo add months of two columns in Oracle database, you can use the ADD_MONTHS function. This function takes a date as input and adds a specified number of months to it. You can calculate the sum of months in two columns by using this function in a SQL query. Simply provide the column names or date values as arguments to the ADD_MONTHS function, along with the number of months you want to add.
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4 min readTo check if two HashMaps are identical in Rust, you can compare their key-value pairs. First, you can check if the two HashMaps have the same length using the len() method. Then, iterate over one of the HashMaps and check if each key-value pair exists in the second HashMap using the get() method. If all key-value pairs match, then the two HashMaps are identical. You can create a function to encapsulate this logic and return a boolean value indicating whether the HashMaps are identical or not.
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8 min readIn Hibernate, to join separate table data columns in a query, you can use the HQL (Hibernate Query Language) or Criteria API. By using HQL, you can write a SQL-like query to select specific columns from multiple tables and then create a custom result transform to combine the data from the separate tables. Alternatively, you can use the Criteria API to join the tables using criteria and then select the desired columns to be fetched in the result set.
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4 min readTo get specific data from XML in an Oracle table, you can use the XMLType data type and XML functions provided by Oracle. First, you need to query the XML column in the table using the XMLType constructor function. Then, you can use XPath expressions to navigate through the XML structure and extract the specific data you need. For example, you can use the extractValue() function to retrieve a specific element or attribute value from the XML document.