PHP Blog
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6 min readTo find unique values from an array of objects in MongoDB, you can use the aggregation framework. One common approach is to use the $unwind operator to deconstruct the array into individual documents, then use the $group operator to group documents by the desired field and use the $addToSet operator to create a set of unique values. Finally, you can use the $project operator to reshape the output if needed. This will allow you to find unique values from an array of objects in MongoDB.
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7 min readTo find an array and a specific value for a field in Mongoose, you can use the find() method with a query parameter. You can specify the field you want to search for and the value you are looking for in the query object. For example, if you want to find an array of documents where the field name has a specific value of John, you can do the following: Model.find({ name: 'John' }, (err, result) => { if (err) { console.log(err); } else { console.
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5 min readTo limit text score with the $gt operator in MongoDB, you can use the $text operator along with the $meta projection operator to limit the documents based on their text score. By specifying a minimum threshold for the text score using the $gt operator, you can exclude documents that do not meet the specified score criteria. This allows you to filter out documents that have lower text relevancy or quality in your search results.
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5 min readTo filter list values in DynamoDB, you can use the CONTAINS condition in a Query or Scan operation to check if a list attribute contains a specific value. This can be used to filter the results based on the presence of a particular value in a list attribute. Additionally, you can also use the NOT_CONTAINS condition to filter out items that do not contain a specific value in the list attribute.
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4 min readTo push to an array in MongoDB, you can use the $push operator in an update operation. The $push operator appends a specified value to an array. Here is an example of how to push a value to an array in MongoDB: db.collection.updateOne( { _id: ObjectId("5f6479c9161e0f3cbfacb4b7") }, { $push: { fruits: "banana" } } ) In this example, we are pushing the value "banana" to the "fruits" array in a document with the specified _id.
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4 min readIn order to enable CTR encryption in RocksDB, you first need to set up a custom encryption object that includes the encryption algorithm and key. This can be done by creating a new instance of rocksdb::BlockCipher and initializing it with the desired encryption algorithm and key. Once the encryption object is set up, you can then pass it to RocksDB when opening a database by setting the Encryption option to the encryption object that was created.
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3 min readTo use regexp_like for wildcard search in Oracle, you can provide a regular expression pattern as the second argument in the function. The regular expression pattern can include wildcard characters such as '.', '*', and '+'.For example, to search for all values in a column that start with the letter 'A', you can use the following SQL query: SELECT * FROM table_name WHERE REGEXP_LIKE(column_name, '^A.
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5 min readTo compare two dates from an Oracle database, you can use the built-in functions and operators provided by Oracle. You can use the ">" (greater than), "<" (less than), ">=" (greater than or equal to), "<=" (less than or equal to), "=", and "<>" (not equal to) operators to compare two date values. You can also use the TO_DATE function to convert date values to the same date format for comparison.
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4 min readTo convert an extracted value from a datetime column to a character data type in Oracle, you can use the TO_CHAR function in your SQL query. This function allows you to format the date and time values as needed.
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5 min readTo generate an ID in Oracle, you can use the SEQUENCE feature. First, you need to create a sequence using the CREATE SEQUENCE statement. You can specify the starting value, increment value, and other properties of the sequence.Once the sequence is created, you can use the NEXTVAL function to generate a new ID each time it is called. For example, if you have a sequence named my_sequence, you can generate a new ID by calling my_sequence.NEXTVAL.
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5 min readThe GROUP BY function in Oracle is used to group rows that have the same values into summary rows. This can be helpful when performing calculations on groups of data, such as finding the total sales for each product category.To use the GROUP BY function in Oracle, you need to specify which columns you want to group by in your SELECT statement.