mysql_fetch_row() retrieves the next row of a result set: When used after mysql_store_result() , mysql_fetch_row() returns NULL if there are no more rows to retrieve.
What is the purpose of using mysql_fetch_array () & Mysqli_num_rows ()?
MySQL_fetch_array() is a function used to retrieve a row from a MySQL database query as an array. It can be used to quickly retrieve a single row from the result set returned by a SELECT query. The mysqli_num_rows() function is used to return the number of rows present in a result set. It can be used to check if any rows were returned after executing a SELECT statement. Both functions can be used in conjunction to loop through the returned result set, retrieve and display each row, and count the total number of rows retrieved.
What is Mysql_row?
MySQL_row is a PHP function used to fetch a single row of data from a MySQL result resource. It can be used to retrieve the data associated with a query executed by the ‘mysql_query’ function. This function returns an array that contains the data associated with a single row in the result set. This array has the same form as that returned by the ‘mysql_fetch_array’ function, with the added advantage that it only contains the data from the specified row number in the result set. The array returned by this function will contain both associative and numeric key-value pairs.
MySQL_row can be used to access the record values in a MySQL table as long as the ‘WHERE’ clause is used to specify the exact row from the result set. It should not be used if the query could return multiple records. In such a case, the ‘mysql_fetch_array’ should be used instead.
What is mysql_fetch_array () function?
MySQL_Fetch_Array() is a PHP function used to retrieve row data from a MySQL database result set as an associative array and/or a numeric array. It takes a resource set of data as an argument, usually from an earlier call to a MySQL database query that returns the data in a resource set. The function returns an array of data that contains both numeric and associative keys to each record within the resource set. The associative keys (if the second parameter of the function is set to true) correspond to the names of the fields in the result set. It is important to note that the function returns a single row of data at a time, after which it must be called again to iterate through the resource set and access additional rows of data.
How to use mysql_fetch_row in PHP?
The MySQL_fetch_row() function is used in PHP to retrieve a result set from a MySQL query. The function returns a single row from the result set as an array. The array can then be used to access the data in the row.
Coinciding with each element of the array is the field name of the column in the MySQL table. If you have a table with the columns ‘Name’, ‘Age’, and ‘Gender’, the array returned by the MySQL_fetch_row() function will have the following fields:
array = Name
array = Age
array = Gender
To use the MySQL_fetch_row() function, you must first establish a connection to a MySQL database. This is done using the MySQL_connect() function and an appropriate set of arguments. Once the connection is established, the query can be performed using the MySQL_query() function.
After performing the query, the MySQL_fetch_row() function can then be used to retrieve the result set one row at a time. To do this, you must enter the MySQL_fetch_row() function after the query as follows:
$row = mysql_fetch_row($result);
Where ‘$result’ is the result set from the query. As the MySQL_fetch_row() function moves through each row of the result set the data will be stored in an array. This array can then be used to access the desired data from the row.
For example, if the query is used to retrieve the Name, Age, and Gender of a person from a table, the following code can be used to access the data:
echo $row; // this will display the Name
echo $row; // this will display the Age
echo $row; // this will display the Gender
Using the MySQL_fetch_row() function in PHP is an efficient way to retrieve and process data from a result set. It provides an easy way to access the field names and their corresponding data from each row. Understanding how to use this function can unlock the power of database driven web applications.
What is the difference between mysql_fetch_array () and Mysql_fetch_assoc ()?
The difference between mysql_fetch_array() and mysql_fetch_assoc() lies in how the results of a MySQL query are returned.
mysql_fetch_array() will return an array that contains both numeric and associative keys, while mysql_fetch_assoc() will only return an array with associative keys. This means that if you only need to access the data with the associative keys, you should use mysql_fetch_assoc().
In terms of performance however, mysql_fetch_array() is usually faster than mysql_fetch_assoc(), since the former only needs to loop through the results once while the latter has to loop through it twice. For this reason, mysql_fetch_array() is usually the preferred method when speed is an issue.