Why is my query returning nothing?

Why is my query returning nothing?

4 Answers. Your query is returning nothing because the execution engine is using an index that is incorrectly referenced by this specific application (Sage BusinessVision) you have to work around the issue.

How to check if SQL query returns nothing?

The IS NULL condition is used in SQL to test for a NULL value. It returns TRUE if a NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.

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 check SQL is empty in PHP?

3 Answers. The easiest way is to use mysql_num_rows(). $cnt = mysql_num_rows($Result); if ( 0===$cnt ) { echo ‘no records’; } else { while( false!=( $row=mysql_fetch_array($Result)) ) { // } }

How do I return NULL if no records found SQL?

If your SQL query does not return any data there is not a field with a null value so neither ISNULL nor COALESCE will work as you want them to. By using a sub query, the top level query gets a field with a null value, and both ISNULL and COALESCE will work as you want/expect them to.

What is Nullif SQL Server?

In SQL Server (Transact-SQL), the NULLIF function compares expression1 and expression2. If expression1 and expression2 are equal, the NULLIF function returns NULL. Otherwise, it returns the first expression which is expression1.

How do I know if Mysqli query was successful?

To check if your INSERT was successful, you can use mysqli_affected_rows() . Returns the number of rows affected by the last INSERT, UPDATE, REPLACE or DELETE query. And check for errors against your query and for PHP.

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 do I run one query after another in SQL?

To run a query with multiple statements, ensure that each statement is separated by a semicolon; then set the DSQEC_RUN_MQ global variable to 1 and run the query. When the variable is set to zero, all statements after the first semicolon are ignored.

Is Empty in SQL?

Use the IS [NOT] EMPTY conditions to test whether a specified nested table is empty, regardless whether any elements of the collection are NULL . The condition returns a boolean value: TRUE for an IS EMPTY condition if the collection is empty, and TRUE for an IS NOT EMPTY condition if the collection is not empty.

How to check if query returns any rows without a result?

– Mark ByersMay 21 ’10 at 19:42 it is not clear if you want a result set returned and then check if any rows were int it, or if you just want to check if a query returns any rows without a result set?? – KM. May 21 ’10 at 19:53

How to check if a SELECT query returns an empty set?

Simple check for SELECT query empty result Ask Question Asked11 years, 2 months ago Active9 months ago Viewed277k times 74 9 Can anyone point out how to check if a select query returns non empty result set? For example I have next query:

How to return NULL or value when nothing is returned from?

For fast, accurate and documented assistance in answering your questions, please read this article. I use the ISNULL () function for things of this nature. if the result is null, will replace it with ” (blank string). This assumes that the subquery returns no more than one row, which might not be valid.

Can a subquery return more than one row?

This assumes that the subquery returns no more than one row, which might not be valid. If the answer to your question can be found with a brief Google search, please perform the search yourself, rather than expecting one of the SSC members to do it for you.