Search has query that will return no results

1. How do you execute a SQL query only if another SQL query has no results?
2. How do I know if MySQL query has nothing returned?
3. What results does an SQL query return?
4. What is the result of a query called?
5. How do I run a SQL query after one?
6. How we can run SQL query show the table and run different queries?
7. How do you check if SQL result is empty?
8. How do I check if a query is empty in PHP?
9. How do I check if SQL query returns nothing PHP?
10. How do I retrieve a row in SQL?
11. How do I select a query in SQL?
12. How do I select a row in SQL?

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 ).

How do I know if MySQL query has nothing returned?

To access the database you should use PDO. Checking if PDO has returned any results is actually pretty simple. Just fetch the results and if the array is empty then there was nothing returned from MySQL.

What results does an SQL query return?

The SQL SELECT statement returns a result set of records, from one or more tables. A SELECT statement retrieves zero or more rows from one or more database tables or database views. In most applications, SELECT is the most commonly used data manipulation language (DML) command.

What is the result of a query called?

Answer: A ResultSet is a Java object that contains the results of executing an SQL query. In other words, it contains the rows that satisfy the conditions of the query. The data stored in a ResultSet object is retrieved through a set of get methods that allows access to the various columns of the current row.

How do I run a SQL query after one?

Simply put three queries one after the other in a . sql file, with semi-colons after each statement, then execute it as a script (either on a SQL*Plus prompt using @scriptname. sql or in TOAD/SQL Developer [or equivalent] using its script execution function).

How we can run SQL query show the table and run different queries?

1. How to run SQL Queries against the database?
2. How SELECT works?
3. • We want to retrieve all the data included in the table: all_info. ...
4. available is shown in the drop-down menu Table Info:
5. • Select the option "all_info", and the description of the table will appear:
6. Saving results as CSV.
7. Hiding Columns.
8. Ordering Data.

How do you check if SQL result is empty?

The JDBC ResultSet doesn't provide any isEmpty(), length() or size() method to check if its empty or not. Hence, when a Java programmer needs to determine if ResultSet is empty or not, it just calls the next() method and if next() return false it means ResultSet is empty.

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

PHP empty() Function

The empty() function checks whether a variable is empty or not. This function returns false if the variable exists and is not empty, otherwise it returns true. The following values evaluates to empty: 0.

How do I check if SQL query returns nothing PHP?

You retrieve the row and check if it's empty… if not you just use $row: $sql = 'SELECT p2gtext FROM p2g'; $result = $pdo->query($sql); // Retrieve the row (will return an empty array if no records match) $row = $result->fetch(); // If the row is empty, show your error msg.. if ( !

How do I retrieve a row in SQL?

SELECT column1, column2 FROM table1, table2 WHERE column2='value'; In the above SQL statement: The SELECT clause specifies one or more columns to be retrieved; to specify multiple columns, use a comma and a space between column names. To retrieve all columns, use the wild card * (an asterisk).

How do I select a query in SQL?

The SQL SELECT Statement

1. SELECT column1, column2, ... FROM table_name;
2. SELECT * FROM table_name;
3. Example. SELECT CustomerName, City FROM Customers;
4. Example. SELECT * FROM Customers;

How do I select a row in SQL?

To select rows using selection symbols for character or graphic data, use the LIKE keyword in a WHERE clause, and the underscore and percent sign as selection symbols. You can create multiple row conditions, and use the AND, OR, or IN keywords to connect the conditions.