Quick Answer: How Do I Check If A Query Is Empty In PHP?

How do I know if SQL Server update query was successful?

You can use the return value of the ExecuteNonQuery to check if the update was successful or not.

You can use @@ROWCOUNT to get the number of rows affected by the last query.

This can be used to decide whether your WHERE clause actually matched something, for example..

How do I check if a list is empty C++?

list::empty() is an inbuilt function in C++ STL which is declared in header file. list::empty() checks whether the given list container is empty(size is 0) or not, and returns true value if the list is empty and false if the list is not empty.

How do I know if my eloquent is empty?

$result->isEmpty(); The isEmpty method returns true if the collection is empty; otherwise, false is returned.

How do I check if SQL query returns nothing PHP?

mysql_query() will only return FALSE if the query failed. It will return TRUE even if you have no rows, but successfully queried the database. This should work. If a query returns nothing it will be a boolean result and it’s value will be 0.

What is collection in laravel?

A collection is a laravel class that uses arrays internally and adds many features to them. You can create a collection simply by using collect method like this. … You can apply all the collection helper method available in Laravel. When we apply helper methods on eloquent collections, they do not query the database.

Is Empty in mysql?

SELECT * FROM yourTableName WHERE yourSpecificColumnName IS NULL OR yourSpecificColumnName = ‘ ‘; The IS NULL constraint can be used whenever the column is empty and the symbol ( ‘ ‘) is used when there is empty value.

What does Mysqli_query return if empty?

For successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query() will return a mysqli_result object. For other successful queries mysqli_query() will return TRUE. A count of zero is a result of one row.

How do you assign a default value if no rows returned from the select query?

Insert your default values into a table variable, then update this tableVar’s single row with a match from your actual table. If a row is found, tableVar will be updated; if not, the default value remains. Return the table variable.

How do I check if a SQL query has returned nothing?

test if count == 0 . select FOUND_ROWS(); it will return the no. of rows returned by select query.

How do I check if a query is successful in PHP?

You can check it with this function. If you are using mysql_query in the backend (whatever $DB->query() uses to query the database), it will return a TRUE or FALSE for INSERT , UPDATE , and DELETE (and a few others), commands, based on their status. if the value is 0 then it wasn’t successful, but if 1 then successful.

How do you check if the table is empty in SQL?

Hello, You can run a COUNT(*) on the table; if it’s empty it return 0 = count of rows.

What is empty DataFrame?

DataFrame – empty property The empty property indicates whether DataFrame is empty or not. True if DataFrame is entirely empty (no items), meaning any of the axes are of length 0. Syntax: DataFrame.empty. Returns: bool, If DataFrame is empty, return True, if not return False.

How check if database is empty?

SELECT COUNT(DISTINCT `TABLE_NAME`) AS anyAliasName FROM `INFORMATION_SCHEMA`. `COLUMNS` WHERE `table_schema` = ‘yourDatabaseName’; The above syntax returns 0 if the database has notable otherwise it returns the number of tables.

How do I know if my Android database is empty?

Set up a query-method (either in your ContentProvider directly) or in another class using your ContentResolver with a projection for one column (ID should do the trick). Then see if the cursor contains anything or not. You can query database with total row count. If it is > 0 then you can run your next code.

How do you check if an ArrayList is empty?

The isEmpty() method of ArrayList in java is used to check if a list is empty or not. It returns true if the list contains no elements otherwise it returns false if the list contains any element.

What does Mysqli_query return?

Returns FALSE on failure. For successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query will return a mysqli_result object. For other successful queries mysqli_query will return TRUE .

How do you execute a SQL query only if another SQL query has no results?

The common table expression ( WITH clause) wraps the first query that we want to execute no matter what. We then select from the first query and use UNION ALL to combine the result with the result of the second query, which we’re executing only if the first query didn’t yield any results (through NOT EXISTS ).

What is MySQLiquery PHP?

Definition and Usage. The mysqli_query() function accepts a string value representing a query as one of the parameters and, executes/performs the given query on the database.

How do I check if a list is empty in Python?

Check if a list is empty in Pythonif not seq: In Python, empty lists evaluate to False and non-empty lists evaluate to True in boolean contexts. … len() function. We can also use len() function to check if the length of a list is equal to zero but this is not recommended by PEP8 and considered unpythonic. … Compare with an empty list.

How check data is empty in laravel?

How to Check Collection is Empty or Not in Laravel?Laravel Collection isEmpty() Example.Syntax: $collecton->isEmpty();Example. public function index() $collection = collect([]); $output = $collection->isEmpty(); … Output: true.Syntax: $collecton->isNotEmpty();Example. public function index() $collection = collect([]); … Output: false. I hope it can help you…

Is Empty collection laravel?

Collection Methods: isEmpty Standard Laravel definition: The isEmpty method returns true if the collection is empty; otherwise, false is returned.