Remove Data SQL Method

The removeData function allows you to Remove specific records (rows) / Data from a table within a given data source (database). You can selectively remove data based on certain conditions.

Parameters:

1. dataname (Data Source Name):

   • Replace 'your_data_source_name' with the actual name of your data source (database).
   • This parameter specifies the database where the table exists.

2. tableName:

   • Replace 'your_table_name' with the name of the table from which you want to remove data.
   • The table name identifies the target table for the removal operation.

3. dataToRemove:

   • This parameter is an array of arrays, where each inner array represents a record (row) to be removed.
   • Each inner array contains values corresponding to the columns in the table.
   • In your example, we have two records to remove:
     • [1, 'John', 30]
     • [3, 'Bob', 35]

Execution:

1. Setting Up the Data Source:

   • Ensure that you've established a connection to the specified data source (database) before calling the removeData method.

2. Calling the removeData Method:

   • Once you've set the appropriate values for dataname, tableName, and dataToRemove, invoke the removeData method.
   • The method sends a query to the database engine to delete the specified records.

3. Handling the Result:

   • The method returns a promise that resolves with an object containing the following properties:
     • acknowledged: A boolean indicating whether the operation was successful.
     • message: A success message if data removal is successful.
     • errorMessage: An error message if the operation encounters any issues.

Example Usage:

Suppose we have a table named Employees with columns id, name, and age. We want to remove the records for employees with IDs 1 and 3. Here's how you can use the removeData method:

const dataname = 'your_data_source_name';
const tableName = 'Employees'; // Assume this table exists
const dataToRemove = [
  [1, 'John', 30],
  [3, 'Bob', 35]
];
 
// Call the removeData method
db.removeData(dataname, tableName, dataToRemove)
  .then((result) => {
    if (result.acknowledged) {
      console.log(result.message); // Log success message
    } else {
      console.error(result.errorMessage); // Log error message
    }
  })
  .catch((error) => {
    console.error('An error occurred:', error); // Catch any unexpected errors
  });

Notes:

• Adjust the dataToRemove array to match the specific records you want to delete.
• Handle any errors by catching exceptions using .catch().